12 Monarch Diseases, Parasites, and Caterpillar Killers 🐛☠️😱

ByTony Gomez
Monarch Diseases, Parasites, and Prevention Info & How to Raise Healthy Monarch Butterflies for Release
Raising healthy monarch butterflies relies on using simple raising techniques that promote monarch health and will prevent monarch diseases from occurring in the first place. The sad truth is, once your monarchs are sick, it’s usually too late to save them…

The explosion of comments and questions I receive about monarch diseases suggests they’re a common problem for many raisers. There’s still a lot of work to be done to help everyone raise butterflies with (at least) a 90% survival rate.

In the past few seasons, I’ve raised hundreds of butterflies from tiny monarch egg. The only casualties I’ve experienced are from carelessness (rushing cage cleaning), and accidentally bringing in monarch predators with milkweed…mainly small spiders.

Monarch disease and death do not have to be a regular part of your raising experience.

My goal is to bring you an awe-inspiring and joyful raising experience free of monarch diseases and death….or at least bring loss down to a tolerable level, so you can experience the joys of raising, while helping the struggling monarch population to rebound.

Are you ready to get serious about disease prevention and raise healthy monarchs? Let’s do this…

12 Common Monarch Diseases, Parasites, and Caterpillar Killers + How to Prevent them

Here are 12 monarch health issues that can be largely avoided with a few simple precautions:

 

1. Tachinid Flies

Tachinid flies are hard to differentiate from all the other flies in your garden just innocently pollinating the milkweed. However, if they’re sitting still, look for hairy flies with big red eyes:

Tachinid Fly Parasitoids lay their eggs on monarch caterpillars. The maggots burrow inside the caterpillar and start eating it alive, slowly killing it. Discover how raising monarchs can help them avoid this fate...
Be Suspicious of a red-eyed fly asking your caterpillars to babysit

These parasitic flies lay tiny eggs on monarch caterpillars that will need magnification 🔍 for confirmation:

tachinid fly eggs on a monarch caterpillar. Macrophotography reveals what is often undetected by the naked eye.
Photo by Sarah Wilson of Tallahassee, Florida

The hatching maggots burrow inside the caterpillar and feed from the inside out, eventually killing it. 🐛💀

You can typically tell your caterpillar’s been compromised when it starts to grow smaller and skinnier. Often, it will appear small if it attempts to pupate. The caterpillar often dies while forming its chrysalis. Soon after, white tachinid maggots will exit the caterpillar and repel to the cage floor, leaving long white strands of evidence hanging from the deceased caterpillar.

Monarch Caterpillar Healthy Development Pre Chrysalis
Instead of Growing Big and Plump…
Common Monarch Diseases and caterpillar Killers- Tachinid Flies
…a tachinid-infested caterpillar will eventually grow smaller and skinnier
Monarch Parasites- Tachinid flies lay eggs inside monarch caterpillars. The tachinid larvae eat the caterpillar from the inside out before emerging as tachinid maggots. When this happens we euthanize the affected caterpillar (which will already be close to death) and remove the tachinid maggots and/or pupae.
Two Maggots Emerge

If the caterpillar still manages to form the chrysalis, you’ll start to see dark spots on the chrysalis in the next few days…the maggots will soon emerge. Soon after, they will each form a dark red pupa:

If you find this mysterious tic tac shaped pupae at the bottom of your butterfly cage, a tachinid fly has parasitized one of your monarch caterpillars.

Prevention Tips:

  • Only bring in monarch eggs for raising
  • If bringing in caterpillars, try to collect caterpillars less than 4/10″ (instar 2 and smaller)

Although, I recently had maggots emerge from a small (instar 3) monarch caterpillar I was raising. It was likely parasitized as a small instar 1 or 2 caterpillar…

When tachinid parasitism occurs it’s very disappointing, but these parasites will not spread to other caterpillars in your cage, since they can only be spread by the adult flies. When you find maggots or red tachinid pupae in your cage, simply remove them and raise on!

More info about tachinid flies here

 

2. Ophryocystis elektroscirrha (OE)

OE is a protozoan parasite that caterpillars ingest on milkweed. It’s spread through microscopic spores coming off the wings and bodies of adult butterflies. These protozoa multiply inside the caterpillar and can cause weakness, disfigurement, and an untimely death. You are most likely to notice symptoms of OE infection in the chrysalis or the butterfly. If you suspect your butterfly has severe OE infection, releasing it will only spread the parasite to future monarchs.

Prevention Tips:

Want to know more about OE and disinfecting monarchs, milkweed, and raising supplies? Click here

💀 BLACK DEATH 💀

 

3a. NPV (Nuclear Polyhedrosis Virus)

Commonly referred to as black death, your caterpillars will deflate, turn black, then liquify like something out of a horror movie! This virus can also affect chrysalides as the entire monarch chrysalis turns black.

Prevention Tips:

  • Raise 5 Caterpillars MAX (per cage) so habitat is easy to keep clean 
  • Use a mesh cage that allows good ventilation, allowing water to evaporate
  • Vacuum up frass, wipe down and dry cage daily
  • Rinse milkweed cuttings and leaves with water before serving
  • Clean cages with a diluted 5%-10% regular bleach solution (1 part beach to 10 parts water) at the end of every season, or use a pre-diluted chlorine bleach cleaner
  • After bleach treatment, rinse cages thoroughly with water (and dry) before reusing or storing away. 
  • Caterpillars leaking fluid or refusing to eat for more than 24 hours should be separated from the rest
  • If you have sick caterpillars or chrysalides turn black, disinfect the affected cage before raising more monarchs…and switch out the milkweed supply!

More info on NPV

 

3b. Pseudomonas (Bacterial Disease)

This bacteria can be found in soil and on plants. This bacterium thrives in warm, moist conditions which is why it’s important to have a habitat with good air flow where excess moisture can evaporate. Pseudomonas typically affect caterpillars that are already weakened by other diseases. Similar to NPV, monarch caterpillars and chrysalides will slowly fade to black death.

Prevention Tips:

  • Raise 5 Caterpillars MAX (per cage) so habitat is easy to keep clean
  • Raise Indoors (by open window) to keep caterpillars out of heavy rain 
  • Use a mesh cage that allows good ventilation, allowing water to evaporate
  • Use stem cuttings instead of potted plants to eliminate soil from their habitat
  • If using potted plants, cover the soil or water with a hydrogen peroxide mix to kill pathogens
  • Vacuum up frass, wipe down and dry cage daily
  • Rinse milkweed cuttings and leaves with water before serving
  • Clean cages with a diluted 5%-10% regular bleach solution (1 part beach to 10 parts water) at the end of every season, or use a pre-diluted chlorine bleach cleaner
  • After bleach treatment, rinse cages thoroughly with water (and dry) before reusing or storing away. 
  • Caterpillars leaking fluid or refusing to eat for more than 48 hours should be separated from the rest
  • If you have sick caterpillars or chrysalides turn black, disinfect the affected cage before raising more monarchs…and switch out the milkweed supply!
 

4. Tainted Milkweed

It’s hard to imagine that anyone selling milkweed would treat it with pesticides, since the vast majority of milkweed customers are buying it to support monarch caterpillars and butterflies. Unfortunately, this is not always the case…

In the world of raising butterflies, tainted milkweed often rears its ugly leaves when people run out of milkweed for their caterpillars and are forced to make a milkweed emergency run to the nearest store/nursery. If you ever have to do this, make sure you are purchasing pesticide-free milkweed, or your poor caterpillars will never get the chance to finish their amazing transformation…

If your caterpillar has ingested pesticides it will often expel green vomit. If this happens, rinse the caterpillar off under a faucet, then place it on a new milkweed source immediately! If the current milkweed has been treated with systemic pesticides, the chemicals are inside the plant and can’t be rinsed off.

Another sign of pesticide poisoning is when a caterpillar dies in the middle of forming its chrysalis. This occurs when caterpillars ingest insect growth regulators, which include organic pesticides like neem oil.

Both of these events can be disturbing and disappointing, but here’s how you can largely avoid them:

Prevention Tips:

  • Find local milkweed sources that grow plants without pesticides
  • Find online milkweed resources that grow plants without pesticides
  • Plant more milkweed in your garden to avoid having to make emergency runs
  • Realize pesticide companies are not referring to caterpillars when they list their products as organic and/or safe for beneficial insects

growing tip: if you suspect nursery plants have been treated with systemic pesticides, cut them back to 6-12″ so healthy new stems and foliage can emerge. The regrowth will be fine for future caterpillars. (wait 60 days to use treated plants again, just to be on the safe side.) 

Find Pesticide-free Milkweed Resources

 

5. Trichogramma Wasps

Until recently, I thought bringing in monarch eggs assured you of hatching healthy monarch caterpillars. But there’s a new parasite in town… Trichogramma wasps lay their eggs inside of monarch eggs. If your egg turns completely dark (instead of only dark on top) monitor it for 48 hours to insure it’s not a viable monarch. If it doesn’t hatch, squeeze the egg inside the milkweed leaf and discard or little wasps will emerge in about 10 days!

When monarch eggs get dark spotting, the egg has been compromised by parasitic wasps and the monarch embryo will not survive to become a munching monarch caterpillar...
Bad News
A healthy monarch egg will turn dark on top a few hours before hatching. This is the baby monarch caterpillar's head about to eat its way to freedom...
Good News

Prevention Tips:

  • If you see a monarch female depositing eggs, collect them right away
 

6. Chalcid Wasps

These mini parasitic wasps stalk your j’ing caterpillar waiting for the perfect moment to parasitize it…right after the caterpillar forms a chrysalis. While it’s still soft, they lay their eggs inside. Hundreds of wasps will eventually emerge from the chrysalis at the expense of your deceased monarch…

Youtube video

Prevention Tips:

  • Use fine mesh enclosures to raise monarchs. Larger holes in laundry baskets will allow these impossibly small wasps access to your monarchs during this most-vulnerable time.
  • If raising outdoors, do not leave your habitat open for long periods while cleaning and check the cage for flying insects before closing…better yet, clean cages indoors.

note: chalcid wasps are found worldwide, but concentrated in tropical and subtropical regions

 

7. Anal Prolapse

It's not known what causes anal prolapse in monarch caterpillars, but this condition is always fatal to the poor caterpillar.
Photo Courtesy of Lori Anne Probst Photography

When this occurs the caterpillar’s rectum protrudes from its anus, leaving a vibrant green ball exposed at the end of your caterpillar. It’s not known what causes this, but it’s always fatal to the caterpillar.

 

8. Dehydration

I realize this isn’t a disease, but it’s a far too common problem that is taking precious monarchs away from us before they bloom into beautiful butterflies. Dehydrated monarchs can get stuck inside their chrysalides causing deformation and death. They may also have issues forming them.

Prevention Tips:

  • spritz milkweed and caterpillars daily with a  spray bottle filled with water- make sure the caterpillar cage has good ventilation (i.e. a mesh cage) so the water evaporates and there isn’t condensation inside the habitat that could cause disease
  • Hydration of monarchs must start at the egg stage for healthy development

Some experts and enthusiasts disagree with spritzing milkweed/caterpillars, but imagine eating food for two weeks without water…and staying healthy?!

 

9. Invisible Predators

These are the monarch predators that you unwittingly invite in to your cage, trapping them inside with your unsuspecting monarchs. I have done this with small spiders and stink bugs. This can be a problem when you raise on potted plants because of all the nooks and crannies where predators can easily avoid detection.

Prevention Tips:

  • raise monarchs on small cuttings or individual leaves so it’s easier to inspect the milkweed
  • thoroughly rinse milkweed before serving it up to monarch caterpillars
  • spray potted plants with water to detect spider webs
 

10. Bacillus thuringiensis (BT)

This naturally-occurring bacteria is used in powders and sprays to protect food crops. It has become a widely used pest management tool to control the spread of gypsy moth caterpillars in spring, with all other caterpillars (including monarchs) becoming collateral damage.

When ingested, BT ruptures the gut lining of monarch caterpillars. The irritated caterpillar stops eating and will die within a few days.

BT can be legally used on certified organic plants.

Prevention Tips:

  • don’t just ask if the plant was grown organically.
  • do ask if Bacillus thuringiensis (BT) was used specifically
  • don’t use BT around milkweed and other host plants
  • thoroughly rinse any plants you think may have been accidentally exposed
 

11. Flea & Tick Treatments 🐱🐶

A community member recently contacted with this cautionary tale…

She had just applied a topical flea and tick medicine on her cat. The cat had shown interest in the caterpillars and rubbed against their cage several times. Two days later, all of the caterpillars were on death’s doorstep and had to be euthanized.

If this happens to you, rinse caterpillars, cage, and milkweed with water and maybe they’ll recover. Otherwise…

Prevention Tips:

  • keep pets recently treated with flea and tick medicine away from growing caterpillars.
  • If you’ve handled a dog or cat that’s had a flea treatment applied, wash your hands before handling monarchs, milkweed, or raising supplies.
 

What should you do if you suspect your monarch has a disease or parasite, but aren’t 100% sure?

Isolate the egg, caterpillar, chrysalis, or butterfly and monitor it for confirmation of an issue. If the questionable individual is kept in a separate food container or mesh habitat, it will not spread potential pathogens to the rest of the monarchs you are raising.

 

12. Wood Butterfly Cages

Wood raising cages are hard to disinfect, which can cause ongoing disease issues. According to Monarch expert Dr. Karen Oberhauser:

“It is difficult to clean wood cages unless you have access to an autoclave. At Minnesota, we use wood and screen cages to rear larvae, and have successfully decontaminated them in an autoclave. If you use mesh or plastic cages, they can be decontaminated by soaking them in a 10% bleach solution (approximately 10 ml Chlorox bleach to 100 ml water) or 100% ethanol for at least 15 minutes, then rinsed well. Use the bleach solution to soak any tools that you use to transfer larvae, rinsing them after they are soaked. Wipe down countertops and other surfaces with the bleach solution in areas in which you have reared larvae or kept butterflies. The spores survive long periods of time (over a year), and can also survive freezing temperatures, so equipment that you used last year or left outside over the winter will still be able to infect larvae.”

Prevention Tips:

Just an ounce of prevention in raising monarch butterflies will help you avoid monarch diseases, parasites, and death, so you can grow healthy monarchs to support the butterfly population!

Please read through the comments below for more info about Monarch Diseases, Parasites, & Caterpillar Killers. For further assistance raising healthy butterflies, a ✬✬✬✬✬ rated PDF download on How To Raise More Monarchs, with Less Effort is available for purchase HERE

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  1. I had a caterpillar who went inti chrysalis while smaller than average. When the butterfly emerged it was smaller and fell off the covering of chrysalis to bottom of cage. I tried to keep it in sunlight and let it grab on to stick to attach to screening but it would not hold on. The wings wer wrikled and could no dry. I tried to straighten them out but could only do some. It is still alive and am wondering if I should mess with wings again.

  2. This summer, I have successfully raised about a dozen caterpillars, most from either eggs that hatched or from 1st instars. I had one egg that had the wasp parasite, which I removed, & I found one 5th instar that I brought in but kept separate as a precaution (good thing, because it had maggots). Most have done well, seeming almost cheerful on their milkweed, which I took as cuttings and washed routinely to keep mold, etc. off of it. I thought, “What could go wrong” about letting my daughter’s science teacher take 2 for the classroom (w/care instructions that I provided). Well… she had trouble keeping the milkweed from drying out in her hot classroom, had them in a mesh container that I learned had been used last year for painted ladies & never cleaned, & then threw another “mystery caterpillar” in with them (which I think eventually died). I rescued them on Thursday & thought they were nearly dead. Both looked shriveled & barely moved. They perked up w/fresh milkweed leaves & a spritz of water, but today (Sunday) the larger of the 2 (3rd instar) looked a bit forlorn & eventually kind of “flopped over” & is lying seemingly lifeless. I have seen them go still before molting but not usually on their side. I’m reluctant to assume it is dead, since the filaments still seem rather erect, as though there is still life. In past years, when a caterpillar died, the filaments & overall body became decidedly more shriveled in appearance. Have you seen this before? How long should I wait before assuming/confirming death?

    1. Hi Sally, if its lying on its side something is wrong…I would separate the caterpillar from others and monitor its progress. Typically, if a caterpillar appears sick for more than 48 hours I would euthanize. You can wait a little longer if you’re not sure.

  3. It’s going to frost tonight, should I bring inside some caterpillars that are outside feeding on milkweed in my yard?

    1. Hi Marli, you could…and maybe bring in some milkweed leaves to put in the refrigerator, or stem cuttings to make sure there’s still viable milkweed

  4. I need help! First year having milkweed plants in the garden and have been getting a lot of caterpillars… Did not see any chrysalis so bought mesh cages (thought wasps were killing them). Not sure if it’s the wrong one since one of the sides is clear plastic.

    I lost a few caterpillars to the fly with the red eyes… But have others form chrysalis – – they look healthy But then they have turned white and/or look half eaten.

    what can i do? There are a bunch of aphids on all my plants but from what I’ve read they don’t hurt the caterpillars… Is the plastic side of the cage heating them up too much? Help!

    1. Hi Robin, the PVC window side of the cage should not be places to receive direct sun. If caterpillars run out of milkweed or milkweed is dried up, they have been reported to eat chrysalides. Here’s info about Oleander aphids

  5. HELP! I have had a few different problems with one batch of caterpillars. All hatched from eggs indoors, placed in covered food containers until instar 2, fed with the normal sandvine leaves that my cats love which were rinsed with water.

    So far 7 of the 36 have turned darker and just died on the bottom of the cage or maybe the side (not hanging like classic NPV). Its been about one a day. A few hours after death they leak a brown liquid and sometimes smell, but are only a little darker, not really black. I’ve isolated sick ones and wipe out the mesh container with bleach, wash with soap and water and the rinse with just water so as not to poison the cats. Meanwhile many of the others have already pupated normally so I’m choosing to continue to raise the few left who seem okay in the same container. This has been going on for about a week.

    Today I noticed something different – red frass, some that is hard and some that is watery. And now one caterpillar who was hanging in a J started to split its skin to pupate but it was like the green inside slipped down inside the skin and it is now hanging from the skin only. If it actually finishes splitting (it has paused now), the chrysalis will fall.

    My questions:
    1) Is this NPV?
    2) Is there any chance the normal chrysalides will eclose normally if they were exposed to fellow caterpillars with NPV?
    3) If they do eclose as butterflies, will they infect other butterflies or the next generation?
    4) Is the red poop and strange happening with this pupating cat caused by the NPV, or is this a new problem? I’ve never heard of anything like it.

    Any other tips are appreciated! I’ve never dealt with NPV like this. In the one rare time I had it in the past it was from caterpillars I had collected, not eggs, and they did the classic turning completely black and hanging. This is really mystifying me.

    1. Hi Trista, this doesn’t sound like any of the diseases or other issues listed here. I would separate the problem caterpillar/chrysalis and monitor them to see if the issue becomes clear….good luck!

    2. Trista – I don’t know how old your post is, but that was not red frass. That’s the pupae of the tachinid fly. They are first white maggots and then become the red pupae. I’ve kept some to see what they look like and they are the tachinid. Hope this helps if you hadn’t found out by now.

  6. I am a first time raiser of Monarchs. I usually do Painted Lady Butterflies so this is all new to me. I have 3 Chrysalis that have a silk strand hanging from them. Does that mean that they are infected with a bug of sorts? Should they be removed?

  7. Just had a horse hair worm come out of a caterpillar in front of our eyes 4″ long. I cannot find ANY info on this being a “thing”. The caterpillar died. I understand these worms get their hosts to throw their body into water (not an option here). These worms need to be in water to survive where they lay in wait for MONTHS for a mate. I took pictures of the worm in a container “dry” it was dying so I added water and it sprang back to life where I guess it thinks a mate may be coming. I will squash it …but I contacted the State to see if they are interested since we are having wetter years.

  8. Hi there. A caterpillar raised from an egg on washed leaf cuttings in its own cage and in it’s 5th in star vomited green liquid for at least 14 hours. It was moved from my living room to a quiet dim location and vomited a little but began eating again. Less than 24 hours later it formed a J and then a perfect looking chrysalis. Today it emerged beautifully. Should this one be released?

    1. Hi Tasha, I have never heard anything like what you’re describing. Sounds possibly like potential exposure to pesticides or other chemicals. If the butterfly seems healthy and ready for flight, I would release…good luck!

  9. One of our biggest problems this year was the abundance of aphids. We had barely any monarchs lay eggs and almost no caterpillars. We had many that did not emerge from their eggs and now my last one seems to be compromised by a tachanid fly. Does anyone know any natural ways to keep the aphids at bay while protecting the monarchs? Lady bugs?

  10. Hi Tony.
    I have kind of a crazy story.. we live in Colorado and while taking a road trip a few weeks ago I picked up a Monarch with broken wings from a gas station parking lot in West Virginia thinking I could repair her wings. By the time I realized they were beyond repair she began laying eggs. In Virginia I picked up a milkweed and butterfly enclosure. She passed away and I now am back in Colorado and had 6 (not down to 5) caterpillars that hatched (not sure if they were hers or already laid on the plant when I bought it). I have no experience but have been trying to learn what to do. The cats look healthy and are eating. Today I picked up some wild milkweed for them since they ate all of the other one. I am keeping them in the enclosure on my balcony. What else should I do for them and will they be able to chrysalis and emerge and migrate properly? Thanks so much!

    1. Hi Cally, sounds you were destined to be a monarch mama…congrats! If you want more raising info, be sure to sign up for raise the migration emails here

      1. Hi Tony,
        I have been raising Monarchs since the ’90’s! This year I had over 50 between caterpillars and eggs yet I’ve suffered some devastating attrition due to black death and other unknown ailments. To date I’ve released 24 Monarchs with quite a number of chrysalis’ still in the works. I live in rural Sussex County NJ and obtained all of my Monarchs the old fashioned way – looking for them! The milkweed has come from the farm where my horse is boarded and from several other locations along rural roads. I don’t suspect poisoning but it is still distressing to find them dead at all stages – from little babies to dying before they form the chrysalis.

        1. Hi Carol, it’s really hard to say if you don’t know whether the milkweed has been sprayed with pesticides. The best way to insure your milkweed isn’t tainted is by growing your own or only collecting from areas you’re 100% sure haven’t been sprayed. good luck!

  11. It seems my first comment didnt go through. So my caterpillar #4 had an anal prolapse, and has not eaten in about a day. #1 was a chrysalis that fell and i believe has passed. #5 has strange spots that may be either scars or possibe OE??? The spots/splotches look like the heartline. most are near the rear. Most look under the skin, but a few look like scar tissue. Also this caterpillar was found missing 1 antenna and the other antenna was bit off. So maybe it had a scuffle w predators and the splotches are scars?? On the plus side #9 appeared, it was hidden in plant. #5 was hanging in J today, so may be about to pupate.

  12. I should that #5 s unusual spots or blotches, look almost way the heartline looks. most look like under the skin, almost like a bruise. a few look like something punctured the skin and its almost scab like. The skin that looks scab like is smooth, but looks tougher then the rest.

  13. I was having a great season raising and releasing 46 monarchs from eggs found in my milkweed garden. Towards the end of the season, I suddenly had a couple dozen 3-5th instar cats on my milkweed and they stripped it down to nothing. So rather than having them starve, I brought them in and gave them cut milkweed from neighboring fields. Not ONE has survived. Some died while pupating or failed to eclose and now I know the cause. TACHINID FLIES. I have 15 chrysalises that I am sure are infected. I sadly euthanized today even though I knew they were already dead. I dissected the chrysalis to be sure of the cause and there were 3-5 larvae in each one. I am sick. I wish I could add a picture, but maybe nobody wants to see that anyway. I had naively thought that we didn’t have tachinid flies but now I know we do and I am more determined to collect more eggs next summer!

    1. We’ve had a great season up to now with about 50 healthy robust caterpillars and butterflies
      My latest group is stuck at about the 3rd and 4th enstar
      They are eating like the previous groups I had this summer. Do you think it’s necessary to disinfect all the leaves they eat. Any thoughts

  14. Hi there! I have a chrysalis that from day one has been brown, should I euthanize?

  15. This is the first year we’ve noticed OE symptoms in the monarch butterflies that are hatching around our house. Three have hatched with disfigured wings, others haven’t hatched at all.
    We live in an area that has a lot of natural milkweed growing.
    My question is, now that OE seems present in my backyard is there something we should do so that it doesn’t come back again next year on the milkweed?
    We live in MN so it will freeze,

  16. I have had a very sad September 2018 with my monarch caterpillars/butterflies that I either brought in as eggs or small caterpillars. I have lost caterpillars to Tachinid flies, anal prolapse, and now butterflies to OE. My OE butterflies that emerged from chrysalis stage were deformed with crunched wings and one that had miniature wings on a normal body. Sadly all were euthanized. On the other hand, my swallowtails were very successful this year.

  17. Asking for advice. Yesterday afternoon, I transferred all my cats from a spent incarnata in my garden (all leaves had been stripped by the voracious cats), over to organic curassavica that I bought through a vendor recommended on this site (so I’m pretty sure it’s organic, and the info sheet with the plants reinforced that info). I brought these pots in due to being in the hurricane’s path. Only the largest cat (4.5 cm) has wanted to eat, scarfing a little over 2 leaves last night. Now he has crawled down to the floor and put out some dark green vomit. Should I isolate him? What about the others who are not wanting to eat? Thanks in advance!

    1. Hi Andrenne, it’s always best to isolate and monitor until you figure out if there is an issue. Tony

  18. I’ve been doing some research on NPV and it seems that there is a bad smell associated with the black death. I have lost 6 caterpillars to what I think is NPV but I have never noticed a bad smell, none of them turned black like all the pictures I was seeing and only one ever really liquified after it tried to form a chrysalis. My milkweed supply outside was well past its prime and I had a random pumpkin plant grow in my milkweed this year that has some white fungus (at least I think it’s a fungus) on it. Could their deaths be from a fungus or am I just in NPV denial?

    1. Hi Chelsea, monarchs can also get bacterial diseases like pseudomonas where the chrysalis will also turn dark

  19. Hi everyone, this is my first year raising monarchs……we started with just 2 cats this year so we could ensure we were caring for them properly. My first one has already resulted in a beautiful butterfly and was released a week ago. The second one is currently in chrysalis, but i think something may be wrong with it. The chrysalis had started to turn clear but then went very dark. You could see the monarch wing pattern inside for a day or so but it went very dark black. It stayed like this for about 2 days, and now the chrysalis is solid black. If you shine a light on it, you can still see the orange wing pattern inside the chrysalis, but it just looks solid black to the eye. It has been like this for a few days. I have no other cats or chrysalis in the enclosure so no other monarchs are at risk….I am just wondering if anyone thinks this sounds like black death? Or if we should keep waiting to see if it ecloses?

    1. This sounds viral or bacterial. If the chrysalis stays like this more than 48 hours I would remove and euthanize…

  20. My Caterpillar ate and began forming a chrysalis, but stopped, and has died. What happened?

    1. Hi Stephanie, this is a common symptom of exposure to insect growth regulators…pesticides.

  21. also, if you are using milkweed outside that does not die back you are giving OE a chance to flourish.. the milk weed needs to be cut all the way back once a year and or plant the stuff that dies back. This is like the most important thing. People trying to help Monarchs often plant milkweed that stays around all year and are actually harming the population and spreading OE to the wild population.

  22. I had a butterfly totally eclose and inflate ( if that is the correct term) her wings. She hung for several hours then I moved her outside to a plant. The temps were in the low 70’s . She hung on the plant until dusk another 4 hours and hadn’t moved so I returned her to the mesh cage because the temps were going into the 50’s over night. In the morning she was dead and her wings were still very soft and almost heavy feeling. I checked her for OE and did not see any spores. Just wondering what could have been the problem?
    I also want to thank you for your great website. It has answered a lot of questions for me.

    1. Hi Judy, if it wasn’t OE, perhaps it was exposure to a chemical or pesticide? Not sure on this one, but hopefully it was a fluke. 50’s for temps are not an issue.

      1. Just a thought…but maybe her wings were still soft and damp feeling from the dew forming over night? So sorry you lost one. This time of year seems to get tricky with them.

  23. I just had a crysalis eclose today that has deformed back wings. When you look at it head on, with its wings folded, they are just curled out about 1/4 inch from the edge on one side and 3/8 inch from the edge on the other (not symmetrical). This butterfly pupated on its side and seemed small at the time to pupate. Do you think it has OE? And should I still release it? Thanks.

    1. Hi Elise, it sounds like there is a health issue, likely OE…I would not release it.

  24. I am very new at raising monarchs. Only doing it because a butterfly laid lots of eggs on my aesclepias tuberosa and the plants could not support that many caterpillars. Anyway, I have one little guy who doesn’t look right. I could send you a photo. There appears to be something stuck on his face. It looks similar to his skin, and I dunno, but he can’t seem to eat.

    1. Hi, it sounds like the face cap might be stuck. They shed the caps when they are molting. When this happens it’s ‘mechanical failure’. There’s not anything you can do besides hope it can get it loose so it can start feeding again.

  25. hi i found a monarch that had been killed by black death and there was a large fith instar on the underside of the leaf will he make it to adult.(it was in the wild) and i don’t know if i should bring it in

    1. you can bring it in…just keep it separated from other monarchs. good luck!

      1. Hi I have had a few monarchs and all have hatched quickly an healthily but my last one is in Chrisalis stage but it looks like there’s a whole in it and the side with the hole is a much lighter green then the rest of it it’s almost a yellow color compared to the emerald color of the rest of him I can see he is still moving inside but the part with the hole is ware his wings will develop do u think he will make it I do wat to do please help much thanks kalani

        1. Hi Kalani, all you can do is monitor and hope for the best once they’re in chrysalis stage. Good luck…

  26. i have 3 monarch chrysalises that have been in chrysalis stage for a week and a half now. all 3 have started to turn black at the top and I thought they were starting to get clear so they would emerge. they have been like this for 3 days now. are they dead? what happened? I have tried finding pictures online of this but nothing matches. 🙁 very sad!

    1. hi Lorrie, if the chrysalides turned black (no butterfly markings) it’s likely NPV or bacterial.

  27. I just had a male monarch hatch today and it’s grasp is weaker than normal. It can fly, although it does not have much stamina.
    Please help, this is my 5th year of monarch raising and I have never lost a chrysalis or butterfly yet! I am really worried.

    1. Hi Theresa, if it’s still weak, there is probably an issue like heavy OE infection. I suggest euthanizing in these situations to prevent spreading disease.

  28. Hi, I am a first-time monarch raiser and I fear something happened to our little friend. Everything appeared to be going well, the chrysalis formed and was a beautiful emerald green, it turned dark and you could see the design of the monarch wings through it, but then it never opened. The chrysalis has been dark for several days now, and based on the reading I have done on your site, it appears our friend did not make it. Does this sound like a particular disease that may have caused these symptoms and untimely death?

    1. sorry Andrea, if the chrysalis turned transparent with butterfly markings it’s possible the butterfly had heavy OE infection and the chrysalis was stuck shut. Otherwise, I’m not sure what would cause the butterfly to fully develop but not emerge…

  29. I’m in Northern Florida. Have had terrible problem with Aphids..I’ve tried dampened cloth or paper towel and wipe them, towel with alcohol, coffee in the surrounding soil, marigolds planted close by…nothing has helped. Any other suggestions?

  30. Have you ever experienced cannibalism? My first time raising and one of my cats took a bite out of a freshly formed chrysalis 🙁

    1. Hi Sam, if you have fresh milkweed and the cage isn’t overcrowded, this is not an issue.

  31. Hi. I have a bunch of black swallowtail Caterpillar in my herb garden. Most seem to be doing well and attaching themselves to the branches and side of the box like the should be. But i have three that have no control over their bodies. They are on their side with a shaking like motion and Horn stuck out on the ground. Are they sick? Is there anything I can do to help them?

    1. Hi Cheryl, there is something going on….is it possible any plants were treated with ‘organic’ pesticides like neem oil or BT? could also be a parasite issue. hopefully you can figure out the issue…good luck.

  32. Hi Tony,
    I have a 3 in star caterpillar that has a nub for an antenna on its head and what looks like grey streaking along one side of its body. I looked through the 11 diseases you described on your website, but I can’t figure out if this is anything to be concerned about. I have isolated it for now. Do you know what it could be?

    1. Hi Katy, isolate and monitor…not sure what the issue is from your description but at least you don’t have to worry about the other caterpillars now.

  33. Hi Tony,
    My children and I found a monarch egg on some local milkweed and decided to see if we could care for it and raise a monarch. When the egg hatched and our little teeny caterpillar grew we were thrilled! We had a butterfly habitat and fresh locally growing milkweed. Things were going well. Around the time she should have began her transformation she hung from a leaf and made a J. She seemed a bit undersized maybt, but healthy and vibrant and munching and pooping. Anyway, she formed the J shape and I took my kids to the dentist. When we got home she looked dead! She had fallen down and bright green splatters were all over the lead she was hanging from and the newspaper in the floor. It looked like a piece of her bottom maybe came off. Kids were crying , we were devastated by the loss. Took her outside and she started to move again! Couldn’t beat to kill her, so I left her in the habitat outside protected. In the morning I thought she would be gone, but she was still alive. Day three and still alive and pulled herself back on the leaf and hung again, but nothing happened. She’s still alive but not eating much. Her antenna look sort of grated and her bum and muddled seem injured. What’s going on? We are just so upset and don’t know what happened and what to do now. Advice welcome! I have photos, but not sure how to share them!

    1. Hi Jen, this doesn’t sound good. All you can do is monitor and make sure there’s fresh milkweed (which it sounds like you’ve done)…if you didn’t grow the milkweed, there could be an issue with pesticides.

  34. I officially hate tachnid flies! l brought in ONLY eggs this year after loosing many to tachnids last year. I wash off my leaves, use mesh cages purchased from here, and still had 8 of 20 beautiful green chrysalis’ become mottled and brown parasitized fly maggot bags! I am discouraged because everything I am reading about tachnids and monarchs makes this seem impossible. Had I brought in cats I could have had many more even with the tachnid invasion. Sigh…

    1. Hi Joya, most raisers would agree with your take on tachinids. Adult flies only lay eggs on caterpillars. I’m not sure how your caterpillars become parasitized. Sounds like a fly might have snuck into the enclosure when you entered the cage?

      1. My question is much like Joya’s, (Aug. 31st). I have raised monarchs for many years, and until now, only had an occasional tachinid fly, and then, only from a chrysalis formed by a cat which had been gathered as a cat. This year, I gathered over 400 eggs which were placed in more than 50 fine mesh enclosures over the course of the season. Until about a week ago, I had lost only one monarch this year. Within the last week, I have lost 15 chrysalides (in 12 separate enclosures) to the notorious tachinid. I also thought that if I only collected eggs, used fine mesh enclosures, fed carefully washed MW cuttings, never overcrowded and kept everything clean, tachinid flies would be the last thing of which I’d need to be concerned. I’m quite puzzled. How could this be happening? Any suggestions for avoiding a repeat situation next year?
        Thanks so much for maintaining such a helpful site!

  35. Hi, Tony.

    Thank you for everything you do for monarchs – and us!

    We experienced NPV for the first time this year (we are in Toronto), even though we always rinsed the milkweed. As a result of that sad experience, we now bleach the eggs and milkweed. Do you not believe in using bleach?

    As if NPV wasn’t enough, we also learned a tough lesson vis a vis flea medication. Our two cats don’t go outside, but fleas found their way inside this summer necessitating the use of flea meds. May I suggest not only keeping flea-treated pets away from caterpillars, but that humans create a barrier between themselves and caterpillars and all of their equipment. Before I enter the monarch room, I wash my hands and promptly dry my hands on paper towel BEFORE touching anything, including the faucet to turn it off. I then use the same paper towel to open the fridge. I use my other hand to take the processed milkweed out. The paper towel in my other hand turns the doorknob to the monarch room, turns on lights, etc. I put the paper towel and milkweed down, and then don a fresh pair of disposable gloves to work with the caterpillars.

    It is a pain in the butt, but I have gotten used to it with repetition. I haven’t lost any since beginning this routine (knock on wood). The felines get their second flea treatment on Sunday, and we still have 13 chrysalides and 20 caterpillars.

    1. Hi Kate, we don’t bleach but we rinse milkweed thoroughly with water and spray/rinse eggs with water too. By doing this and using elevated cuttings so caterpillars aren’t crawling around in frass, we never have any issues with sick caterpillars. I don’t use gloves to handle caterpillars, but do wash hands before handling them. Good luck with all your monarchs!

  36. I planted 3 milkweed plants this summer in hopes of helping the Monarch population. I did get to see 3 caterpillars munching away at the leaves but then one day the aphids came and multiplied even as I tried to keep them off. After that the caterpillars left and all my milkweed died. What do you suggest for next years planting to keep the aphids away. By the way I have seen 3 or 4 Monarchs flying around my yard. I also have fennel growing and had 13 Black Swallowtail caterpillars on that plant and hatched 2 out of a butterfly cage. Unfortunately one of them came out of the chrysalis with deformed wings. It is always fascination and exhilarating to watch the transformation. Cant wait till next summer to do it all over again.

  37. Hi Tony,
    I would like to tell you about something that happened to 3 chrysalis, within 1 hour’s time. I have yet to come across anything like it in my research. It looks like I am unable to attach a picture to this.
    I put my largest cat’s in an aquarium for the last day or two of their munching feast. They walk off, climb the side and find a spot under the rim to J hang and make their chrysalis. I have it covered with fine tulle stretched on a frame to keep predators out and the cat’s in.
    I noticed strange movement. I saw the “thrashing” action of the chrysalis as it finishes the skin shedding process. But instead of the shed skin being up near the cremaster, the entire chrysalis was hanging upside down! The newly shed skin was being held by a couple of silk threads around the button. What’s happening?
    How can I help it? Since I move the chrysalis and re-hang them with a string in a habitat to protect them from predators , perhaps I could loop the downward hanging chrysalis’s cremaster with the string, tighten it quickly and it will be able to hang correctly. I had to try before it fell from the silk threads.
    I formed a loop and tried many times to slip it quickly over the tiny black cremaster. Each time, it thrashed, the loop came off.
    I pulled the troubled chrysalis from the clinging silk threads and laid the poor deformed chrysalis body on paper towel. I resumed my attempt to slip the loop over the cremaster. After a couple tries it worked! I pulled the loop tight. It was now hanging in the correct orientation.
    However, the amount of time it hung “upside down” may have been too long. Gravity had pulled in the wrong direction.
    I hung the chrysalis from a pencil. It’s soft green skin was mis-shapen. The head end had partially collapsed. As the chrysalis continued it’s “process” of completion, the shell was not right. It seemed the insides were ballooning on one side. This can’t be good.
    It looked to me as if the “face” of the shedding skin did not detach as it should have, at the start of it’s shedding.
    I am thinking with the face skin still attached, it may have tried to free itself with the typical “thrashing” movement it does. It may have dislodged the cremaster from the silk button, the shed skin must have caught some of the silk threads at the button site. It hung upside down (face up) too long.
    A bit later that ballooning side chrysalis skin appeared to have split open. The poor thing was still moving, as if trying to finish shifting itself into shape. Not good. I will move it to the freezer to euthanize it.
    NOT AGAIN! Within the next hour, the same thing happened to 2 more J hanging cats! What is happening to them? I again helped re-hang the 2nd. But the third… I left alone as it had not been caught by silk threads and it fell to the bottom, 12″ below. I later decided to pick it up with tweezers to take a picture.
    I took a picture and it shows what looks to be it’s legs that have slipped out of the slit. I later viewed the exposed head and front legs, almost a translucent green. That is why I doubt there is a parasite critter involved. I placed all three in the freezer.
    I have not seen anything like this described or pictured online in 4 years of research.
    I would be interested in your thoughts about this “happening”. It was just so odd to have this happen to 3 J hanging cats within an hour. I am relieved it stopped, whatever the cause! I have many more to go. This year, I found OE spores on one new hatch. One J hanging cat seemed to be leaking green fluid-which I removed immediately! Last year (my first year) I released +50 Monarchs, and there will be + 100 this year. Overall, a good year for Monarchs!
    I would appreciate your thoughts on this, if you have any idea.
    One other question regarding your “clippy”. You say he is mating, and you wonder if he will join the migration at least part of the way. If there are Monarch’s still laying eggs and mating, then they aren’t the “super generation” who will begin their reproductive phase next spring. Do all Monarch’s join in the migration, even though their life is near it’s end? Or do they stay behind and never have that “urge” to fly with the rest who are gathering to migrate?

  38. The leaves on my milkweed get a white film on them. Then the aphids come. Took over one whole section of the milkweed. Affected the zinnias as well.
    This happened last year as well.

  39. Hi Tony,
    My monarch was stuck in the chrysalis so I tried to help it out (before I read about OE) anwho my 11 year old daughter was crushed, crying pretty hard seeing this helpless creature dying, I tried to leave it outside for a bird but she kept going outside to check on it, so I let her bring it back inside, to make a long story short I’m desperately trying to find the most humane way to euthanize the poor thing, so I read about ziplocking and freezing , it’s 3 am here and she’s sleeping , please tell me I did the right thing by doing the freezer method.

    1. Sorry to hear about your butterfly Lindsey. You definitely did the right thing by euthanizing as it was probably heavily infected with OE parasites. Euthanizing can be done by freezing or putting it inside a paper towel and squeezing. Tell your daughter the butterfly is in a better place and finally flying free.

  40. I had been having a late summer success with raising cats either by bringing in eggs or instar 1 stages into the enclosure. We received 30 inches of rain during Hurricane Harvey. We did not flood but many of my plants could not handle that much rainfall however the milkweek seemed to be fine. All the cats that were fed that milkweek have died. First they would move very little almost and would wither. I am wondering if the amount of rain may have affected the milkweed nutrient content. I will probably never know for sure but wondered if you have heard of that before. Sorry I didn’t take any photos of the cats. The good news is I still have 7 chrysalis that should be popping out this week!

    Thank you for all the time and effort you put into the website!
    Diane

  41. Hello!

    Thank you for the info from your site – this year was my first raising eastern swallowtail caterpillars (they love to lay eggs on my dill!) I had 4, and 3 made it to crysalis, and became beautiful butterflies that I released. I noticed one of the cats appeared to be expelling a brown liquid, so I quarantined him from the others, and cleaned out their houses to keep from spreading any potential sickness. The cat actually made it to crysalis, but his was smaller and brown, unlike the other green crysalis. The lil guy/girl did hatch, but over a week later than the rest. It seemed ok I thought, but the wings weren’t as straight and hald an antenna was missing. The abdomen was more curved than the others too (almost like a wasp shape). A couple days later after it’s wings were dry, I tried to see if it could fly, but the poor thing fluttered to the ground. I named it butterwalk, and kept it in the enclosure with various host flowers, sugar water and fresh fruit. After it’s initial attempt to fly, it slowed down quite a bit and didn’t flutter in it’s cage as much. I brought it outside with me a couple times to let it enjoy the air. Unfortunately, Butterwalk passed away today, exactly a week later from hatching.

    I was surmising perhaps it was sick to begin with, due to all the things I noticed (purging, small size, brown crysalis, deformity) and I was actually suprised it hatched at all (our temps got super cold then shot back up in the 90s before it hatched) since it seems super late.

    I am really sad, and going over everything I did to see if I did something to cause it despite my careful research. I did notice a tiny white spider crawling on it a few days ago, but I thought maybe that was from a flower. Butterwalk had been lethargic prior to that – since its attempts to fly really. I can only assume it was OE, but I don’t know enough about it to know for sure.

    I am glad I was able to raise and release a few though, rest in peace Butterwalk!

  42. Hi, Tony,

    After a disappointing first year trying to raise monarch cats, I went through your raising booklet over the winter and decided to raise indoors in the largest- size Kritter Keepers. My goal was 50 healthy butterflies; 85 so far!
    Today I found that one of my rather large cats had pooped a ball of dark pink frass. I moved the four biggest to another cage, euthanized the pink pooper, and scrubbed the cage with an 8% bleach solution. All in new cage are eating and pooping healthy green frass, but two of remaining four in cleaned and rinsed cage are motionless on their leaves. I am okay with euthanizing if you recommend it; I learned last year not to save one at the expense of the rest.

    1. Hi Jan, if you think they are sick you can euthanize, but please make sure they aren’t inactive becuase they’re preparing to molt (shed their skin) Thank you for sharing your lesson not to save one at the expense of the rest of your current and/or future monarchs. It’s an important, but sometimes very hard lesson to learn.

      PS…congrats on your 85 releases!

  43. So about a month ago we had found 12 cats in our little garden area. After researching them, we decided to raise these cats do to their predators. Any ways all 12 have made their chrysalis. I have one here that has been clear for a few days now and still hasn’t hatched. The top of it doesn’t look any different then that one’s that have hatched (4 So far). The top is a little black but I can still see the wings just fine. The looks of this chrysalis hasn’t changed and its been well over 48 hours now.. what should we do about this?

    1. Hi James, it should have come out unless the temps are too cold. It might have died in the chrysalis or could be stuck…this can sometimes occur with severe OE infection. If it doesn’t emerge tomorrow, I don’t think it will…

      1. So as we move into fall, if it doesn’t get warmer (MN), are the 6 chrysalides I have hanging doomed if they don’t get hatched in a certain amount of time? I don’t have a warm spot to move them to (Maybe 65 degF.)

        1. Hi Tom, we still have eggs in the twin cities…you have plenty of time for release with chrysalides.

  44. Hi Tony,
    I had a pupa turn black and when I cut it down and put it onto a paper towel it started leaking black fluid. Would that most likely be NPV? I was careful not to get any of the liquid on my mesh container and will bleach it after the last 2 pupas in it eclose soon. Love your site.. I have learned SO much.. this year will be releasing close to 140 monarchs this year.. double my number from last year!

  45. Hi Tony. I had a monarch eclose just about an hour ago. It’s wings have seemed to inflate normally with the exception of the top right section. It is not crumpled, but is perfect looking but small as when it was in the chrysalis – not inflated at all. Could this be an OE infection or something else? What should I do with this little girl? I don’t think she’ll be able to fly with only three of four wings.

  46. My monarch caterpillar (collected at a school) expelled green liquid when I thought it was turning into it’s crysalis. Do you think the milkweed was bad? If so, should the school take out and replant the milkweed?

    1. Hi Ursula, if the chrysalis looks ok, it might be fine. If it didn’t survive, it could be pesticide related, but usually it would vomit before that point.

      if there are pesticides in the plant, you should still be fine planting the milkweed if you cut it back to the ground after planting to allow fresh growth to emerge.

  47. This is my fist year raising Monarchs. I’ve raised Eastern Black Swallowtails in the past. I first encountered an issue with pesticide tainted milkweed purchased from a local nursery which killed 6 out of 10 caterpillars. I separated the remaining cats that were exposed to the pesticide and they all seemed to pupate without issue. 2 more 1st instar cats were accidentally brought in on cuttings. I have one last caterpillar that seems ready to pupate, but it keeps crawling frantically up and down the enclosure, spinning webbing everywhere, but failing to decide on one spot. What could possibly be going on here?

    1. Hi Heather, sometimes you just have to give them time to work it out. Watching them can be a little nerve-wracking. Either the caterpillar will figure it out, or there could still be an issue…good luck!

  48. I had a caterpillar go into a J tonight, but he missed his silk button and is hanging on a couple strands of silk. Looks like he won’t last long hanging there. Any advice would be much appreciated!

      1. Update: Thanks for your reply Tony! Amazingly the silk held fast and it did not fall! I did put a soft towel underneath in case. It had attached on the side of a jar…we had the jar sideways for a couple days and have rehung the chrysalis to let gravity do its thing.

  49. I have 3 caterpillars getting ready to pupate. One of them is in the j shape, but it is leaking a clear liquid. Is this normal, or a sign of a problem?

    1. I should say that the fluid is leaking where the skin should normally crack open in pupation.

    2. Hi Debbie, leaking is not normal but all you can do is monitor and hope it stops…if the fluid is black, this means the caterpillar has a virus.

  50. Hi, Tony,

    I lost a chrysalis yesterday. I’m struggling to diagnose it since it looks like the caterpillar ingested a pesticide, which I’ve never used in my yard. I don’t hunt for milkweed anywhere else and I don’t take in wild cats. This is the third chrysalis this week. One was Tachnid, one was NPV, and I am clueless at to what this one is. I did euthanize a cat that was trailing red stuff a few days ago, and upon pulling this chrysalis out, I found the same red stains under it. Some of it is thick like dry human blood. Any ideas?

  51. I’ve lost the last 6 caterpillars to Black Death and didn’t know I was spreading it on my hands! I also lost 4 to tachinid flies. It’s been a sad year losing 14 out of 45. But I’ve released 22 so far with 2 chrysalis and 2 cats to go. I will sterilize my hands between cleanings.
    Thank you for all your help, Tony!

    1. Hi,

      I am not Tony, but was interested in your problems. I have now collected and released monarchs for 4 years, and have had more deaths this year than ever before. I am located in central southern Michigan. I have had every problem listed in this email, and a few others including butterflies that have wings approximately 1/2 inch long, crumpled wings, half formed chrysalis, and many with an extremely deformed chrysalis. I am really puzzled since in past years I have had an approximate 90% survival rate. So it appears this year may be a bad one. I always the great information from Tony.

      1. Hi Peggy, sorry to hear you are experiencing these issues….the deformed crumpled, wings are a common issue with severe OE infection, but both of these issues could also be from pesticide/chemical exposure. You could try testing for OE to eliminate or confirm that issue.

  52. This is my first year raising Monarchs. Am fascinated with it all and your website has been so helpful!

    My problem is that my adults are coming out of the chrysalis just fine, appearing healthy at first but then they are not able to fly once their wings are inflated. They just hang around with wings closed and within an hour or two will fall to the bottom of the cage and flutter around but mostly just lay motionless on their sides. Is this OE? So far out of 9 that have emerged in the last month, only one was able to fly off normally. The rest are still in cages and I have put orange and banana slices with hummingbird nectar on top in their cage and some of them appear to be eating. I have about 10 more cats in various stages. They appear healthy and are eating well. If some of these cats emerge and can fly well, is ok to release them or should I not release any of them for fear of transmitting more disease? I am concerned about next year. Is there any way I can prevent this from being a problem then?

    1. Hi Kay, OE would be my guess. The tips in this disease post should give you ideas on how to prevent this from happening. Until, you can increase the success rate, I would still with small numbers so you can improve your process. good luck…

  53. So I had my first cat finally finish its transformation to butterfly but I’ve encountered an issue. He eclosed about 6 hours ago and refuses to try flying he seems very lethargic and the unexplainable part is he keeps leaking a clear fluid a couple drops maybe every hour. Does anyone know what this is. I’m keeping him indoors for the night and going to try releasing him again in the morning.

  54. I had a cat in the J last night and this morning it was deflated and limp with a white string hanging down. I understand this is work of the tachinid fly. However, my cats are hanging with a tulle under them as a safety net and under that there is a towel on the floor. I don’t see any sign of a larva or anything. I’m not sure what to do now. Can the larva hatch into a fly in my room and hurt the other cats? What about the already formed chysilides- can they lay eggs in them?

    1. Hi J…the maggots probably crawled under the towel, where you should find red pupae. They would need to mate before parasitizing more caterpillars.

  55. Hi Tony. I love your website. I’m hooked on monarchs especially since I had my first monarch butterfly in my flower garden in a long time after planting three milkweed plants. I was thrilled to see 7 caterpillars one day about 1 inch long. But lost all of them within 6 hours one day. They were there in the morning and when I looked in late afternoon they were all gone but I did some new very small caterpillars . The smaller ones have now grown to be almost as big as the ones I lost (about 8 days later). I had five of the new smaller ones. Two died overnight and turned into all black smaller caterpillars. I took one of the three left and put in an old lizard terrarium with milkweed clippings. Here are a few questions I hope you can answer if you have a chance.
    1) Any idea on why some of the eggs hatched way later on the same plants?
    2) Is it normal for a caterpillar to shrivel up and turn black within in a 12 hour period over night?
    3) My milkweed leaves are running out so I bought a fourth plan but all of them are starting to have leaves turning brown and multi-colors and our nights are getting quite cool (despite global warming – I’m in SE Pennsylvania.) Should I place the other two caterpillars still on the plant outside with the other one in the terrarium and bring in the house for best chance of survival? Will they eat leaves that are not totally green?

    Thanks very much if you get a chance to answer this!!!
    John

    (PS: I am totally hooked on this and plan to really up my game next season by planting multiple milkweed areas in my yard.)

    1. Hi John: 1) the eggs were layed on a different day 2)not normal…this is probably a bacterial disease 3)At this time of the season, sometimes you have to make due with the best milkweed possible…good luck!

  56. I have a question regarding the anal prolapse problem listed in the article, which says “it’s always fatal to the caterpillar.” When exactly does the caterpillar with anal prolapse die and why does it die? I ask because I currently happen to have a caterpillar with anal prolapse. It’s been eating voraciously, just like a normal cat. Every so often, it has to curl its head back to its tail to separate a just-evacuated fecal pellet that gets stuck to its protruding emerald green anus, but otherwise it does not seem to be terribly bothered by the prolapse. It’s being going along like this for 6 days now, getting bigger all the time. I’m pretty sure this cat is 4th instar, so if I’m right, when it molts the next time, perhaps the anus will be internalized again? If it is not and it remains prolapsed, will the prolapsed anus somehow prevent the cat from making a cremaster when it pupates? As I understand it, the cat attaches to its silk mat using its rear prolegs, correct? So, having a prolapsed anus would not prevent it from going into J-formation. But if it can’t make a cremaster, this would mean that the pupa (chrysalis) would have no means to stay attached to the silk mat and it would fall? But I have read about fallen chrysalides that successfully progress through eclose of a normal, healthy butterfly. So, what if I fashion a small enclosure for this cat I have with a prolopsed anus such that any place where it might attach itself for pupation is high enough for it to have space to hang in J-formation but no more than a couple of inches above the paper towel-padded floor of the enclosure? That way, when it falls immediately upon completing the shedding of the skin (because the rear prolegs are there no longer and no cremaster is made), that fall will not injure the chrysalis. I guess I would have to just leave it lying on the paper towel for the duration of the pupal stage, because there will be no cremaster to which to attach a thread in order to hang the chrysalis.

    Where am I going wrong in this line of thinking? What else can I do the increase the chances that this cat will make it all the way through eclose?

    Or, again, can you please tell me at what point every caterpillar with anal prolapse dies?

    Thank you!

    1. It is too bad that your caterpillar is experiencing this ailment. I’ve never experienced this, but from what I’ve read on this site and others sometimes it is best to euthanize and not let the critter suffer nor let it pass on potentially unsuitable genetics. Given that the survival rate in nature is so low, we tend to forget that losing one caterpillar we have raised from a wee egg may not be the greatest loss, even though it does feel like a huge defeat.

      This isn’t meant to be disheartening or cruel, it is just that we can’t save all the monarchs. Just be comforted knowing that the efforts you are making will make a difference with the monarchs that do survive.

    2. Do you have any follow up on the status of this caterpillar that was luving fine w anal prolapse???

  57. I’d been feeding a caterpillar, brought inside at 2nd instar, with milkweed raised from seed I planted last year. It’s the first time I’ve done this and the caterpillar died after forming about 1/3 of a chrysalis. I haven’t used pesticides on the milkweed, but I’ve read that dying with a partial chrysalis is a result of development inhibiting pesticide ingestion. I have several small patches of milkweed around the yard, but am not sure which patch the bad leaves came from. It’s the end of the season so I don’t expect to see any more cats, but don’t want this happening again. Is there anything I can do about my milkweed plants? None of them have flowered yet. Do I need to destroy them all and start over? If I remove the dead plant material will next year’s growth be safe to eat? About 2 years ago (in ignorance) I used a systemic pesticide on two rose bushes, but the milkweed is no where near that soil. I don’t want to rip out the plants, but don’t want to poison the few caterpillars we’re starting to see in the yard.

    1. Hi Sue, if you’re in a region with true winter, your plants will die back to the ground. If not, you can cut them back to the ground. As a preventative measure, treat the soil with hydrogen peroxide before the plants come up next spring, on the off chance it’s a bacterial issue:

      Milkweed Diseases- Treating Plants

  58. Hi Tony, I just began getting my feet wet on raising monarchs this summer. We have successfully raised and released two. A couple of days ago, a new one came out of its chrysalis and was on the bottom of the Kritter keeper, there was dark brown liquid around it. Despite that, it seemed ok and eventually I out it out on some verbena. It has not been able to fly and over the last two days, it looks as if something is eating its wings from the outside in. Any thoughts on what this might be from? Should I euthanize?

    1. Hi Janet, you can either keep the monarch as a pet or euthanize. If the butterfly is weak it probably has OE parasites and it might be best to euthanize.

  59. Last year was my first year raising monarchs in Washington DC. I raised them on two potted swamp milkweed plants that I brought inside the cage. Out of about 10 caterpillars, I had five who successfully reached adulthood. This year I started with 12 under the same conditions. Three did not make it past 2nd or 3rd instar. The rest were all doing well until the two biggest ones successfully formed their chrysalides. Then everyone else seemed to slow down/stop eating. I waited a good while to account for any molting. It’s been more than 48 hours now. One 4th instar dropped, but showed no signs of the common problems (not deflated, black, or infested, etc). Tonight two others dropped to the floor of the mesh cash (which has been cleaned of frass). At first the balled up in shock. But then after a while they seemed to writhe around as if in pain. I tried to gently move them back onto their plant, but they couldn’t hold on. I also spritzed all the plants.

    I didn’t know about using cuttings instead of the potted plants until I just saw it here. I also didn’t do a good job of cleaning the cage from last year. Bit since I have two seemingly healthy chrysalides, can you think of any other reason for these newly developed problems?

  60. My husband and I have been raising monarch caterpillars here in Southern California for the past 4 years now. Though we have had great success, there have of course been times when caterpillars or monarchs have died. Each time, I have come your site – specifically this page – to figure out what the cause was, and have usually always been able to deduce the culprit. However, recently I have had two instances of caterpillar death that I am having a hard time figuring out the causes for. Perhaps you or my fellow monarch enthusiasts could help.

    The 1st – I had two caterpillars in my large mesh cage, both about 3 instars, and raised indoors since they were at 1 instar. We had been in a heat wave all week, but it had finally cooled down enough on this particular day to be about in the high 80s (down from 100). So, I added some fresh milkweed leaves to the cage and placed it outside in the shade for about an hour and a half. When I came back out to collect it, I found that both caterpillars had produced a dark liquid and were shriveled up and dying/dead. I know that vomiting is usually a sign of tainted milkweed, but this all of my milkweed plants are those that I have grown myself from seed, and I have never used pesticides or chemicals on them. Plus, other caterpillars had eaten it several weeks earlier and were fine. Did the caterpillars become too hot being outside? It is usually in the 100s here in the summertime, and have always raised a good crop of caterpillars.

    The 2nd – We had several large, 5 instar caterpillars outside in the garden that looked about ready to ‘J’ yesterday. This morning I went looking for the chrysalises, but was shocked to find one of the cats laying dead on the walkway next to the milkweed plants. There was no sign of tachinid fly strings, vomit, punctures, or any other disturbance to the body. It appeared fully normal, except when I picked it up it felt slightly floppy and almost deflated (but not shriveled).

    Do you have any idea of what the cause could be for either of these? I would love to be able to avoid these results in the future.

    Thank you!

  61. Have you ever had a caterpillar that keeps trying to eat but seems to have lost the ability to bite and chew milkweed leaves? I currently have a 4th instar that was definitely eating sizeable chunks out of leaves, though more slowly than any other caterpillar I’ve seen. But then it started wandering all over the milkweed and the enclosure, stopping frequently to try biting into a leaf edge to no avail. This is the 3rd day like this. It just seems to “gum” the leaf. It is slowing down, not surprisingly, given that it doesn’t seem to be getting any food, but it is still trying to chomp on leaves. I am making some very young leaves available to it, but this doesn’t seem to help. Is it possible that its mandibles have somehow been damaged or dulled? Is there any way I can make it possible for it to ingest food?

    1. Hi Maria, does it look like an old face cap is stuck from the last molt? There’s not a lot you can do when this happens but spritz the caterpillar with water and see if it can get it loose. I know someone was recently able to spray a caterpillar with a stuck face cap, then pry it off with a tweezers…not an easy task. Otherwise, if this is not the case, not sure what else would cause this…

      1. Tony, thanks for that suggestion. I’ll check. But I do not think this cat has molted since the last time I saw it eat. Amazingly, this cat is still alive, still crawling around, still “gumming” at leaves and not getting shriveling up, as far as I can tell. It’s been 5 days now. All I can think is that it’s actually getting enough of a nibble to keep it alive.

        Is it possible that it got too much latex at some point and its mandibles stuck together? Recalling the last leaf I saw it eating, I remember that it did not first cut off the flow by chewing through the main vein near the stem of the milkweed cutting.

        In a desperate attempt to help it, I blended up some leaves with a little water and then soaked a wad of paper towel with the mush and put that in the container. Maybe it can suck some up.

        I guess it’s just going to stay in this instar until it just runs out of steam. I am just astounded that it can still be alive and crawling around after 5 days like this.

        Thanks for your reply, Tony, and for this wonderful website.

        1. Hello Maria, if its just growing thinner and still not eating, you could euthanize as the caterpillar is slowly starving. I’ve never seen caterpillars unable to eat because of latex build up, but we spray cuttings daily, and the cuttings are always in water so the caterpillars are getting fully hydrated milkweed.

      2. This caterpillar is still very much alive this morning. It does not *look* sick. It just does not get bigger or smaller and still crawls around gnawing at the edges of leaves. There was even one small poop on the floor of the deli container I’ve put it in! But that’s one poop in 5 days.

        I did check it’s face and it does not appear to have “mask” stuck to it. It actually looks completely normal. It just isn’t biting off obvious bits of leaves.

  62. Have my first monarchs in their mesh playpen and yesterday afternoon the first one went into its famous hanging “j”. I’ve just noticed that it has one or two drops of clear colourless fluid on it’s lowest hanging point. Is this typical? I have raised these little fellas from eggs found in my backyard on my A. Tuberosa in mid-August and have tried my best to follow all the tips on the website.

    1. Hi Shelly, I’m not sure what the fluid could have been, but hopefully your caterpillar was able to complete its chrysalis transformation…

      1. Thanks for getting back Tony, it didn’t make the chrysalis stage, it started but got stuck and the back didn’t split open. It appeared to injury itself from all the wriggling in the small hole at its head and soon started to drip its blood. I had to euthanize it after about half an hour of torment for me and the critter. Happily though, three of its siblings have formed their chrysalides and there are four more looking very healthy so far. Appreciate your detailed website, it has been very helpful.

  63. Just a comment about spritzing with water. You said something about “eating for two weeks without water” would be hard. Here in Oregon all the caterpillars have to do that because we don’t get any rain in the summer and they survive. I always thought, just like many vegetarian animals, they get their liquid in their food. ours have too! 🙂 Perhaps different in places that have rain in the summer! 🙂

    1. Hi Ann, one of the best times to see caterpillars in your garden is after it rains because the caterpillars come to the leave tops to drink water. If you ever spritz leaves with water, you will often see the caterpillars move their heads as they drink the water. Yes, caterpillars can ‘survive’ without water, but I wonder if they can ‘thrive’ without it…

  64. My fifth instar was acting oddly today: after crawling to the top of his jar and spinning a button (or at least, 3/4 of one, since it looks a bit thin), he began frantically turning in circles, as if he had lost it while trying to sit himself on it–and yes, his back end was acting as if he was trying to grab the button. Then he moved a short distance away before beginning what appears to be the groundwork for a second button! I left him alone for several hours, and when I came back, he was hanging in his J–from a few strands of silk in between his two partial buttons! I know that this is not normal behavior, and it’s quite likely that something is wrong with him (especially as he was found as a third instar), but I have no idea what has caused this behavior. He was just fine yesterday, if possibly a bit lethargic–but not to the point that would suggest anything out of the ordinary. Fifth instars can be quite stubborn, after all, when it comes to having to move when they would rather not…

  65. Hi, Tony — Our monarch season is still young, but already (over the last week) we’ve brought in nineteen cats in various instars. Thus far all seem healthy and are eating greedily, growing like crazy. It took so much longer in the spring! Yesterday, I found a 1″ cat on one of our milkweed leaves nose-to-nose with a tussock caterpillar (we had a bad experience with those last year, as they basically took over the milkweed overwhelming the supply). This year I’ve found four or five and did them in (didn’t really want to, but saw no alternative). I took a fine pencil point and moved the tussock away from the monarch cat, so as to not harm the monarch, but squooshing the tussock. My question: do they hurt one another? The cat is now in the screened cage on our screened porch, along with the others, and is eating and growing. Do I need to worry about it? We’ve also collected milkweed from alongside the highway, where the highway department cuts but doesn’t spray. I’m glad you mentioned washing off the plants, as we hadn’t been doing that. I’ve been vigilant in patrolling our milkweed and trying to keep insect pests away. The info about all the hazards possible to monarchs reads like a horror story. Thanks for all the great advice. Sincerely, Pam Selbert

    1. Hi Pam, I have never heard of there being any issues between tussocks/monarchs besides competing for milkweed…I would not worry if you have enough milkweed to feed both.

  66. My first monarch chrysalis is deformed as it was formed at the bottom of the case where it was slightly wet and now is flattened and 2 days later it started smelling badly. What am I to do?

    1. Hi Mohit, if the chrysalis has a foul smell, this means it turned dark (correct?) and has NPV, a monarch virus. The butterfly did not survive, so I would discard and disinfect your cage…good luck!

  67. Hi Tony
    This is my attempt to raise monarch.
    I brought in 2 large cats and 3 very small ones.
    Today I had 2 crysalis (one turned black) but did emerged a big beautiful, and look like healthy butterfly.
    They are all together in a big plastic bottle covered with plastic screen.
    I put some cotton balls dipped in honey and soaked in water. Also I cut a cone flower and Joe pie weed flower spritzed with water.
    It will be 66 tomorrow but temps drop at night. Should I still release the monarch?
    Is it sick from black crysalis?
    Please help.

  68. Hello,

    With regards to the anal prolapse, I know that a disease called flacherie in silkworms often yields anal prolapses as a result. Flacherie is a disease caused by bacteria of multiple identities including Bacillus, Streptococcus, and Pseudomonas; viruses; and a combination of both. I believe that these infections are responsible for the anal prolapses. I hope this information was of interest to you. Thanks.

    2. I just had 5 cats all die yesterday and they seemed to have been poisoned as they were vomiting and laying on their sides. 2 of them got an anal prolapse during the process. I euthanized them all. It was so sad my 5yr old is devastated. They were all doing fabulous and then the next morning all dying. My dad brought some milkweed cuttings he got from a plant growing on the side of the road- maybe it had something on it??!

  69. Hi Tony,

    Thanks for your tips, they have been invaluable! I just started raising cats a few weeks ago and two have advanced to the pupal stage. One (which I had quarantined because I brought it in on its fourth instar) pupated last night. The chrysalis looks good, but the old skin did not fall off completely, looks like it may have been impaled by the cremaster. Do I need to worry about this? Should I try manually removing it? I’m afraid to disturb the chrysalis, esp. right now when it is so new. Thanks for your advice!

    Laura, Altamont, NY

  70. I’ve been raising monarchs for about four years now and I’ve had a very successful season, releasing somewhere around 300 butterflies. After dealing with several of the issues mentioned in the article I made a decision to bring in eggs only, no caterpillars. Just following that rule has virtually eliminated disease and parasites. It’s heartbreaking sometimes when I see a cat outside and realize that he probably won’t make it if I don’t bring him. But nearly every time I’ve broken my rule the cat died anyway. And it’s even more heartbreaking to watch that.

    1. yes Lisa, bringing in eggs will definitely boost your survival rate raising indoors, but I still can resist bringing in a stray cat every once in a while…Congrats on a successful season!

      1. Me, either! But I have a low success rate when I do that. I live in coastal southern California so perhaps there are more nasties lurking outside because of our continous growing season. It’s great most of the time but we don’t get the winter cold that kills the nasties. No frost here! Any seeds or bulbs that need cold have to live in my refrigerator for the fall and winter or I have to get established plants from a nursery. I grow a lot of tropical milkweed from seed because it doesn’t require cold stratification and it’s easy to grow here. I toss the plants at the end of the season. I do try to grow semi-native (i.e. native to the southwest US but not to So Cal) but I can’t grow enough to support the huge numbers of ravenous cats.

  71. You say to only bring in eggs. I have been bringing in cats in various stages when I find them. I have only had one die that I am not sure whether or not it was injured. I live in PA. Should I not bring in the cats? I thought I was saving them from birds and other predators. (I saw a praying mantis eating a moth on one of my butterfly weed plants.)

    1. I do it for the same reason, now I began to washer with a 5%bleach (about 6 onzas ) 1 gallon of water i summerge minute, rinse with water,Also i began do it with the leaf im very lucky only one died on 20 thinking is better tham the back yarn with so many predator. Good luck.

    2. Hi Pam, we bring in lots of caterpillars over the season…just letting people know that there are more potential problems when you start with caterpillars compared to monarch eggs.

  72. Tony, your newest email couldn’t have come at a better time. I just started raising a few monarchs and recently I saw two tiny yellow “caterpillars” at the bottom of the monarch cage. I had no idea that they were Tachinid larvae until I read your post. Thank you so much for all of your invaluable advice!

  73. Today while cleaning a container a ~2nd instar was at the top, and was not happy being moved. It threw up green liquid. I put it in a separate container and it seems ok. Is it sick or just mad at me? Thanks!

    1. Hi Vicky, sometimes they will spit out green fluid if they are stressed or squeezed to hard. If it stops right after, probably not a serious issue.

  74. This isn’t about disease (I have conquered the black death) but pesky pests.

    I feel like I’m in a lose-lose-lose situation. If I let my milkweed grow inside my pool cage (to “protect” it), I get ridiculous aphid infestations (co-planting basil did NOT work this year). If I let the milkweed grow outside the pool cage, the natural predators pretty much take care of the aphids, but the monarchs start laying eggs on immature leaves and the eggs/caterpillars don’t survive due to their own predators. If I bring my plants inside after they have acquired monarch eggs/caterpillars, they all survive, and then I run out of milkweed because nature didn’t intend for them all to survive.

    I live in Florida and raise them year-round, so it is an ongoing issue. It was easy to manage my monarch population last year when aphids weren’t so much a problem, but this year the aphids are just out of control and I can’t stand the little yellow buggers. Any suggestions?

    In an unrelated question, my last batch of monarchs emerged with the normal patterns but were a brown color, not the normal orange. Ever seen that before?

    1. Hi Melanie, I’d rather deal with the predators than aphid infestations, which ruin the milkweed you need to support monarchs. Having the opportunity to raise just a few monarchs indoors can make a difference…we don’t don’t bring plants indoors, but use stem cuttings instead:

      Using Cuttings to Feed Caterpillars

  75. Hi Tony, thanks for all the very detailed and specific information on Monarch diseases and parasites — much appreciated. We’re raising Monarchs in the Bay Area of California and so far have only had one or two butterflies fail to launch, some at the chrysalis stage, and occasionally, very sadly, at the butterfly-emergence stage, when the poor thing comes out malformed or crippled. We’ve sometimes in the past tried to keep them alive with watermelon cubes and sugar water, but it’s always just a sad, sad failure.

    It doesn’t happen often, but sometimes it’s necessary to put a malformed but still-alive newly-emerged butterfly out of its misery. We’ve debated about the most humane way to do this. I have opted for the one sharp quick final death smoosh under a flat rock in the garden, and the whole thing is over in a quarter of a second (after profusely apologizing to the poor little guy beforehand). My neighbor puts her malformed-and-will-never-make-it butterflies in the freezer, but the cold, dark, slowly numbing approach seems needlessly long and agonizing. We have cats in the house so I don’t want to try any toxic chemicals (no way I’m bringing chloroform into the house, and where could you even buy something like that anyway?).

    Any suggestions on the best way to perform this horrible, but occasionally necessary humane mercy killing of a failed butterfly?

    1. Hi Dan, I also opt for the ‘smooshing’ when this is necessary, but some people can’t bring themselves to do this. I’m not sure if they experience any pain in the freezer, but if it were me, I’d prefer to go quickly…

      1. I had this same question for Tony regarding what is the best way. I’m not sure I can smoosh. I was hoping that putting them in the garden and letting nature take it’s course however, it was still alive. If it was a dog, we would go to the vet. I’m so glad I was able to watch dozens of healthy monarchs fly away this season. This part of the raising monarchs certainly teaches us about the life cycle. Thanks for listening. I might do the freezer thing. Any other suggestions? Put them back in the garden ?

        1. Hi Debbie, if they are diseased, I would not place them back in the garden. You can always put the monarch in a plastic baggie in your freezer and then discard after 24 hours.

  76. Hi,
    I am in Monroe Township, N.J., and active in our community garden. We had 10-12 healthy appearing caterpillars about 2 weeks ago. They were all present on one day and gone 2-3 days later. There were 2 blackened, desiccated, cat remains on their respective leaves, and no signs of the others. Someone said he’s seen 2 Assassin bugs in the area around that time. Could these bugs have done that damage, are the desiccated remains what one might expect from their action? Is there another possible explanation?
    Thanks.

  77. Hi Tony,

    This is my second year raising Monarchs. I’ve been finding that the shell of the chrysalides sometimes breaks in an improper place while the Monarch is eclosing, often cracking in a circle around the cremaster causing the chrysalis to fall. It seems like sometimes my chrysalides have shells that are too thin and break too easily. I’ve also noticed that occasionally the chrysalis has a deformity where there is a “gap” near where the wings meet. Also I’ve noticed that many of the Monarchs have simply fallen on the ground when trying to emerge. Can you think of any possible cause of this? Thanks

    1. Hi Daniel, sorry to hear about these problems. If emerging monarchs are weak and/or deformed this is a sign of heavy OE infection. Chrysalides can also be deformed from OE, or at least show dark spots. If you are in Southern California, heavy OE infection is a common problem. Milkweed should be rinsed thoroughly before feeding caterpillars, habitats cleaned regularly, and some even use bleach to disinfect eggs:

      Info on using bleach for disinfecting monarch eggs

  78. Like others, this is my first experience trying to raise monarchs. There are 10 beautiful chrysalides all green with gold flecks hanging in a “hatchery” made of a wooden crate covered in mesh on the patio set. Next to them is the caterpillar mesh cage with about 15 caterpillars munching away inside. Most are third instar; one is a first and he has his own space away from the larger ones.
    I learned that cats seem to prefer shade to attach their chrysalis, so I put a cloth on the top of one side of the mesh cage which is proving popular for pupating. It makes relocating the chrysalides easier for me because they’re located close to the side zip opening.
    Unfortunately, we had a strong gust of wind through the patio which caused a milkweed crash, crushing one of the cats. Now I have a brick placed inside the cage on each side, weighing the cage down in place.
    Things were getting back to normal I thought until a couple of the larger cats went into the J. We had a heat wave here in coastal California (90s) at the same time as they were getting ready to pupate. They were large, bright, healthy looking cats, but they only formed a partial chrysalis each. A dark liquid fell from one. I took everyone out and cleaned the cage just in case.
    The milkweed is pesticide-free. The cats looked and behaved healthy before their chrysalis attempt.
    I’ve also started spritzing their cage with water during these hot days.
    Can heat cause a pupating cat to die?
    Colleen

    1. Hi Colleen, dying mid-pupation is a common symptom of growth regulators (pesticides) in plants. They can also die before pupating if they have tachinid fly parasites. If they are in a mesh cage and not getting too much direct sunlight, 90 degree temps are not the issue. Hope you can figure out the issue…

      1. AHHH! I could have written the comment above. In the California Bay Area, raising monarchs for the first time, caterpillars went into the J formation 2 days ago, now they all seem to be dead, and there’s some dark liquid on the mesh of the habitat. We had the same unusually hot weather the last few days, but the habitat was shaded. Don’t think the milkweed had pesticides. It’s really a bummer!

        1. Hi Sue, if they’re oozing a dark fluid (and it has a foul odor) it could also be NPV, a monarch virus. With a mesh cage in the shade, heat should not be a problem. Sorry and I hope you can figure out the issue…

    2. Hi Tony. I fond your site extremely helpful! I have a question… I have an outdoor mesh covered cage consisting of two pots of milkweed. On your site it recommends separating cats who are ready to pupate from the rest of the plants and cats because when they form the chrysalis and exit as a butterfly, you don’t want to mix the meconium with the remaining cats and milkweed. I found a cat at the top of the cage and it looks like it’s ready to pupate. It is not yet hanging in the J formation but it appears to be sleeping. It was facing head up on the side of the cage but near the very top. I moved him to a new mesh cage hoping that he would form a chrysalis in the new cage. When I moved him I realized that he is still sleeping and has since curled up in a ball formation on the bottom of the new cage. After I did this I realized that perhaps I shouldn’t have moved him. Will he wake up and eventually form the chrysalis at the top of the cage? Should I have left him alone? I just would like some advice on what to do next time. My intentions were good but I have heard that you aren’t supposed to disturb caterpillars when they look like they are ready to pupate.

      1. Hi Kristina, if they’ve spun their silk button to hang from, they should definitely not be moved. Otherwise, it should not be an issue.

        At this point, all you can do is leave the caterpillar on the cage floor and see what it does. If he’s still on the cage floor you might want to put a (regular) paper towel under him…good luck!

  79. Hi, I’m fairly new to breeding monarchs, and I moved to New England where I was able to find caterpillars and milkweed everywhere here. I’ve gathered up 10 caterpillars, anywhere from first to forth Instar. The first of them was hanging yesterday and made his chrysalis overnight, and I’m not sure what went wrong, it seems like it had an issue forming, has a hole along a blackened seam of the chrysalis. I have a picture but it won’t let me post it in my comment. It had liquid on it, not really all too green though, kinda was more of a murky clear for the most part with dark bits in parts. . I looked for any larvae all over the mesh enclosure but don’t see anything of the sort. Curious what this could be, and if it would likely have affected the other nine that I have. Thanks in advance for your help

    1. Hi Jeremy, it could possibly be a disease or parasites that haven’t emerged yet. Whenever you start with caterpillars, you can never be sure what they were exposed to before you brought them in. Whenever there are problems, just separate and monitor.

  80. So…..
    I collected a total of 12 caterpillars and only 5 have survived and formed a chrysalis. Last night, one emerged and looked healthy. The meconium, however was green. Today, another emerged and again, the meconium is not normal. It’s green. They haven’t fallen and injured themselves and seem normal otherwise.
    There were caterpillars who were in guess sick because I kept seeing green spots on the paper towel so I separated them all. One did have a fly larvae come out.
    Some of the chrysalis are pretty small and I even have a cat that hasn’t even begun to form one.
    So this batch has had a couple issues. I grew the milkweed I fed them so I’m not sure what went wrong. I’m very disappointed. Are the butterflies ok to release?

    1. Hi Alyssa, if the chrysalides are all small and the butterflies are expelling green fluid there’s definitely some issue that’s affecting them. They could be heavily infected with OE parasites. Otherwise, mosquito spraying can also cause problem cause serious problems, and has for many this season…

  81. This is my 2nd year to raise monarchs inside. I hadn’t found any eggs so I was bringing cats inside (31) total the first 12 went through the stages and produced beautiful monarchs. Now, some of the crysalis are turning black and I see some larva. I removed the black ones but I see a web forming between the other crysalis. is this a sign of further infestation?

    1. Hi Jane, the ‘web’ that you’re seeing is probably just from the caterpillars…when they pupate right next to each other there can be some extra silk. good luck!

  82. Hi. I live in Evans GA, and for the first time I am raising Monarch Butterflies. I love your side. It is very informative. I already been protecting the Gulf Fritillary in my front yard, that only eats my Passion Fruit, But these Butterflies lay eggs like crazy, and I have tons of Passion fruit that wants to take over my yard. I also planted plenty of Parsley for the Swallowtail.
    Then I heard about the Monarch Butterfly. I was touched by the fact, that these beautiful creatures, who only eat Milkweed are about to go extinct. I purchase 3 Milkweed plants (I have no clue what kind). I should had purchase more! I had 3 Monarch Butterflies lay eggs like crazy. Our back yard has a very active wildlife, tons of lizards and birds, armadillos and opossums. I had big Swallowtail caterpillars on my parsley, and the next day I checked and they where all gone. Thats when I started to collect them and raise them.
    Now I had 90 (!) Monarch eggs and small caterpillars. When they are small I keep them in plastic containers, with netting material over the top. When they are big enough I transfer them to the Mesh hampers. I clean them out once a day, and replace the Milkweed. I added Pumpkin, because I am running short on Milkweed. I am growing more Milkweed on the side from seedlings I found in my yard, and also from Milkweed twigs. I did not know they start to root, when left in water. I noticed that a few caterpillars still prefer the Milkweed. But it takes some time to grow. But most of the caterpillars love the Pumpkin too.
    So far 62 turn into beautiful green chrysalises, 10 still hanging in the j position. The rest still munching. So far I lost at least 15. Including 4 chrysalis turning black. The Caterpillars just died deflated or turning black and died.
    I removed the black Chrysalis (and of course the dead caterpillars. One chrysalis I could not remove totally without leaving some stuff from the Chrysalis, because other Chrysalis where hanging too close to the sick one. Now I see that some new caterpillars crawled around the area where the sick chrysalis was. I was wondering, if they can get sick from the residue left from the sick chrysalis. Do you have any idea?

  83. I had one successful caterpillar to butterfly earlier this year. In the past few months I’ve had lots of cats but only four made it to the chrysalis stage and it appears that all of them had tachinid flies even though the chrysalis looked very normal. Any suggestions for next season on how to prevent this, and what is the best type of container to use to raise them indoors?

    I’ve been very involved with being a care giver for my parents this past year, and watching the evolution of the cats has been great therapy!

    1. Hi Carol, sorry you are dealing with those flies…I know how frustrating that can be! The best way to avoid them is by bringing in eggs or very small instar 1-2 caterpillars. I prefer raising them in side opening mesh cages and we just started offering them this season. Here’s more info:

      Big Cube and Baby Cube Butterfly Cages

      1. My monarch butterflies are dying a few days after coming out of chrysalis. None of them have crippled wings or any visible problems. They have gaterade, oranges, and nectar water for food. I have sterilized the cage I have them in with bleach water but still have some dying. Is there anything that would be causing this? This is the first year I have had this problem.

        1. Hi Treva, sorry this is happening. It seems odd that they appear completely normal and then die. Is there any reason you’re keeping them in captivity for a few days?

  84. Hello,
    I just had a quick question about OE that I can’t find an answer to on here or some of your extended articles.

    Can OE infect already hardened chrysalis’?

    I am aware that keeping cats and emerging adults separate is a must to avoid OE spore cross contamination, but will the remainder of the pupa (hatching a few days later from the first) have increased risk of OE infection from the newly emerged adults? Or are they safe guarded from possible “further infection” through the hard chrysalis?

    Thanks!

  86. I have been getting tons of monarch cats for 6 months now in sunny San Diego and as far as I can tell only one has formed a chrysalis and survived. The cats grow up into adults and seem to die when they are almost ready to form a chrysalis. Instead they venture away from the milkweed and find a place to rest until about 12-24 hours later when I find them dying in the u-shape hanging from their middle legs, looking liquefied on the inside. They never turn to liquid completely tho as far as I can see. We have sun all day long and no overcrowding. we have layered the old soul with a different kind of soil. But they all make it to big plump beautiful monarch caterpillars before this sad death occurs. Same milkweed we have had for the entire 6 months. So many dead caterpillars. I freeze them as soon as I find them bc I usually catch them when they aren’t completely dead yet. What do I do?

    1. Hi Kelly, it sounds like you are dealing with NPV…a monarch virus. I would cut back all your milkweed so the monarchs can’t lay eggs on it to allow fresh growth to occur. I would also spray down all the soil around the milkweed with a hydrogen peroxide/ water mixture and hope that makes a difference when the milkweed grows back and the monarchs return…hydrogen peroxide is also good for root growth (with the extra oxygen molecule) so it won’t hurt anything:

      Gardening with hydrogen Peroxide

      Good luck! Tony

          1. That looks similar to what has been happening to mine. I may lose the rest of mine. Only 3 left from 12 starting. Big heat wave (100 degrees) that I’m wondering might have contributed. So sad!!! Ordered the big cube though, so I’m ready to start over!!!!! I better switch out my milkweed.

          2. Same thing has happened to mine. So sad…… Raise them from eggs and then this devastating result. All I know is that my success rate is in the 90th percentile…. So as hard as it is to lose a few, the end result is good. This has turned into such a great hobby.

  87. Hi Tony,
    I live in Ohio and ordered some tropical milkweed plants. Last week we found 3 caterpillars. We didn’t bring them inside. Our very first caterpillar made a beautiful chrysalis. It is now all black. Should I get rid of it? Am I correct in assuming wasps will emerge if I don’t?
    Can I still root cuttings from the plants?
    You have a lovely site. Thank you for your hard work and enthusiam!
    De Anna

    1. Hi De Anna, sorry about the chrysalis. If it turned black prematurely it could have a disease or be parasitized by tachinid flies. If it’s been like this for 48 hours I would throw it out. I hope your other caterpillars make it…good luck!

  88. Help! I live on the west coast of Florida and have my milkweed plants outside. I have had a lot of Monarchs outside during this spring into summer and currently the eggs on my plants do not hatch. I see yellow jackets flying around my plants and don’t know how to get ride of them. With the weather here several Monarchs are still around and lay eggs. however the eggs just sit on my plants. Now the leaves are beginning to turn yellow on most plants and are dropping off which have had many eggs in the past months. I am not sure of what to do to keep these guys going. Any ideas? I am rather new at this!

  89. Been living in Minnesota and raising wild Monarchs through their different stages for about eight to nine years now. Before finding this delightful and insightful webpage I thought I was one of just a few who raised Monarchs I honestly had no idea of just how many people out there raised Monarchs. I started raising them when I moved down to Minnesota because I found the little guys in all their stages quite delightful to watch I even bought a book about butterflies from my local book store.

    I have always had issues with parasites but never severe enough to act upon until today. In the past the good majority of my Monarchs have gone from eggs all the way into butterflies with no issues. Honestly I had no idea that Monarch parasites existed until today really. Today I caught a wild Monarch Caterpillar the only one I’ve seen around in awhile which was strange because its that time of year when their all over the place. Anyways this wild Monarch Caterpillar ate plenty of the unwashed Milkweed I left it the Monarch Caterpillar seemed healthy enough. It shed a few times, grew fat and plump, grew a nice size, then climbed up the bucket I kept it in and cacooned all the way up. A good few days in I could see the Monarch Butterfly taking shape inside the cacoon and got all exited because I thought it was ready to come out. Well the poor thing never came out instead something else came out I’m pretty sure destroying the poor Monarch Butterfly in the process. When checking on the cacoon I found four ugly yellow things sqiggling around at the bottom of the bucket a day later they where small dark brown cacoons.

    I raise all sorts of spiders too so I’m thinking of feeding those nasty flies to my spiders once they hatch.

    1. Hi Tiffany, sorry you have been introduced to the tachinid fly parasites. They can be avoided by brining in eggs or smaller caterpillars. Typically, they’re not a huge issue in Minnesota.

  90. Hello,

    I have been loosing my caterpillars due to Tachinid flies, how can I prevent them from getting on the milkweed plant?

  91. I live in Arizona, and we have milkweed vine growing in our backyard. This vine attracts queen butterflies – I know they are not monarchs, but they are closely related.

    About a month ago I found a caterpillar on the vine, saved it in a ventilated jar, fed it every day, and it turned into a healthy, beautiful queen.

    Since then we’ve found three more, and with each one exactly the same thing happens – it attaches itself somewhere, it’s body changes color to green, it seems to successfully form it’s chrysalis on the bottom half of it’s body, but then the upper half of it’s body stops transforming and it dies.

    Any ideas on what might be the problem? Is this also due to fly infestation?

    1. Hi Jake, if the caterpillar was parasitized by flies, maggots/pupae would emerge from the caterpillar. Otherwise, it sounds like a potential problem with pesticide exposure.

  92. Hello! I have raised Monarchs for several years, and for this batch I have not washed the wild milkweed, only looked at it. One of my smaller caterpillars, (who has not been visibly shrinking,) has a black section on it’s rear end. You can still see the stripes, they’re just a bit faded. It appears there is a white, silky looking, little emptied cocoon like thing on one of the leaves. It does not look at all like a monarch chrysalis, it looks almost like a translucent, wrinkly, white sock. Also, I can see a hard clear shell on the bottom of the terrarium, resembling the face of a monarch cat, with the black stripes and all, but nothing seems to be wrong with the face of the believed to be diseased caterpillar. As you recommend, should I separate the caterpillar immediately? Is this the black death? I have not seen this caterpillar eating. Does it have to do with the not clean leaves? Should I clean them now?
    Basically, what do I do?

    1. Hi Mayah,

      the hard, clear shell on the bottom of the cage is a monarch face cap. This happens every time they molt (shed their skin). If a caterpillar is visibly shrinking, this is usually because it has been parasitized by tachinid flies.

      I would just separate and monitor as you were planning. Good luck!

      PS…I always recommend cleaning milkweed leaves before feeding caterpillars to prevent spread of bacteria or disease spores.

  93. Hello! My daughter found a Monarch caterpillar, brought it in, it ate and ate, attached itself to the underside of the jar she had it in, it hung for a period of time, then eventually went limp. (never went into the J shape) Also, 2 or 3 black small pellets were found at the bottom of the jar, and eventually the dead caterpillar dropped down, too. We’ve never seen this having successfully raised many Monarch. Do you have any idea what this was all about??

    1. Hi Jo, the caterpillar was parasitized by the tachinid flies discussed on this page. They can be avoided by bringing in eggs.

  94. Hi Tony, thanks so much for all of your work on behalf of monarchs. I know that many people are benefiting from it. I wanted to let you know about two things. Dr. Karen Oberhauser is a friend of mine and I was up in Minneapolis for a conference in August. We were discussing tachinid flies and a paper she had written some time ago. Her lab has actually discovered 3 new species of the flies because citizen scientists have been sending the pupae or the adult flies into her lab. If you could tell your readers to send their specimens to her lab, instead of destroying them it would be a great benefit to science. You never know when there may be a new species! The same goes for the parasitic wasp. You can check the MLMP website for information on how to do that. I hope you remind people to report their data to MLMP and to journey north on a regular basis. All of the data is critical to help scientists understand what is happening to the monarch population.

    The first and second instar caterpillars that just quit eating and eventually die? We call that “failure to thrive” and in a large percentage of them (I forget the number, sorry) it is due to tachinid fly parasitism. If you dissect the larvae you would find the fly. I thought that was pretty cool.

    Thanks, Trecia Neal Monarch Watch Conservation Specialist

    1. Hi Trecia, I will add a link on the disease page for any that are interested in sending in specimens. I would also suggest you contact the owner of this facebook group:

      The Beautiful Monarch

      Holli is very interested in the scientific components of raising and has lots of interesting (publication quality) macro photos/videos of tachinid flies and other monarch parasites/diseases. Thanks for posting!

    2. Hi I am currently raising monarch caterpillars for the first time and this morning I went to check on them and one of them was on my window seal and surrounded by some green discharge it’s still pretty small I believe third instar. So I separated it from the others to monitor it do you know what this could be?

      1. Hi Shawna, green discharge can be a symptom of pesticide exposure, but if the others are ok, it might not be anything. Separate the caterpillar and continue to monitor…good luck!

        1. One of mine was on the bottom of the “house” with a thin green discharge around it this morning. I put a leaf near it and it climbed on. I removed the paper towel and cleaned the area. No pesticides are ever used in my yard and I always wash the milkweed thoroughly in plain water before putting it in for them to feed on. I have 2 who are getting quite large. The one who had the discharge was behaving as usual during the day. I just checked on them and it is at the top of the house like it might want to start forming a chrysalis, but there is a little bit of the green liquid around the mouth area. My other butterfly seems fine. Should I worry about the one with the discharge?

          1. Hi Kate, all you can do is monitor at this point, but I would probably move the other caterpillar to a separate enclosure if possible…good luck!

    3. What is the MLMP website? I can’t seem to access it. I’d LOVE to send some specimens but need more info. Thank you!
      -Diane Rose
      MyMonarchMonoligues/Facebook public page

  95. Hi, I have had problems with so many different beetles, flies, mites and aphids on my milk weed plants. After a while, the leaves turn black in color. I wash the leaves with just water and some times squish the aphids and mites, but they just come back. Is there anything I can do? Thank you for all the wonderful information you provide.

  96. Hi Tony,
    This year I finally am raising y own milkweed from seeds,but there are too problems:

    1. I have not seen one Monarch, and

    2. there are tiny yellow bugs ?) forming within the newest leaves. Are these harmful? If so, how do I delete them?

    Thanks, Gail

  97. I have been raising and tagging Monarchs for over 10 years. I use 10 gallon aquariums with a wire mesh top. I am having a problem this year that I have never experienced. After the butterfly has emerged from the chrysalis, it is failing to properly “pump up” its wings. After the stunted wings dry, the butterfly will fall to the bottom of the cage and eventually die. This is happening to approximately 1/3 of the butterflies that emerge so it is not a minor issue. Does anyone have any idea what the problem may be? I see no evidence of parasitic wasps. Many thanks.

    1. OK …. after further internet research, it appears that the caterpillars are infected with OE. When the butterfly emerges from the chrysalis, the OE has weakened it and it does not have the strength to hold onto the chrysalis or it cannot pump up its wings. This is exactly what I am seeing.
      I collect caterpillars from milkweed patches in the yard. I assume the caterpillars already are infected with OE. I place them in aquariums and feed them milkweed cut in the yard. I assume that I am just continuing the OE problem. If the caterpillars that I harvest do not have OE, it sounds like they can pick up the spores on the milkweed that I bring in to feed them. True??? I think my solution is to stop rearing the caterpillars indoors for this season. Comments, please. Thank you.

      1. Hi Jim, if you’re in a region where OE is an issue, it’s vital to start raising from eggs and to clean your milkweed before feeding caterpillars. Some people in continuous growing regions also bleach the eggs/milkweed to kill the spores. Please research before trying as too much bleach can dissolve eggs…

    2. Hi Jim, it sounds like it could be OE parasites or possibly exposure to pesticides. If you’re washing the milkweed and cleaning the cage regularly, it’s hard to believe so many butterflies would have such severe OE infection. If not a pesticide, perhaps another chemical…was the milkweed treated with anything to deter milkweed pests like aphids? Tony

  98. Hi Tony,
    A neighbor who also raises Monarchs asked me to ask you (and/or the fans) this because she is too upset/embarrassed to ask–I had mentioned rinsing off the milkweed leaves before using them to feed her cats. She washed the stem and leaves from her home grown plants in soapy water (she said she used dawn) then rinsed thoroughly twice and dried. The small (all hatched about 5 or fewer days ago) cats began dying within a day after she added this milkweed. Some turned black, some made j’s and died. She feels awful about it. Was the mortality probably due to disease or did the soapy water wash (even though rinsed twice) do the cats in? The cats were in more than one cage. Apparently some cats are still alive. She also said the milkweed had not been sprayed with anything and had been fine up to now. (I am not sure if the living cats are in a different cage or had different milkweed.) She had previously raised cats to adults and had been careful about disinfecting and cleaning.

    I would like to reassure her if it was probably not her fault (ie disease not soap). I feel bad for mentioning rinsing the milkweed. The eggs came from wild milkweed from an abandoned field.

    1. Hi Jessica, I rinse our milkweed with cool tap water…no soap! Yes, if the soap was not rinsed off it could probably kill the caterpillars. Pass on the info to your friend and tell her not to be too hard on herself. We all make mistakes along the way, and learning from those mistakes will make her raising process better next time.

      1. Dawn dish soap is ridiculously toxic, just do a little research and you will never believe their seemingly animal friendly adds again, run!

        1. Municipal water is fraught with chemicals, if rinsing leaves considered fresh rain water

          1. I have never had any issues using our tap water in Minnesota and know many others around the country that do the same. Is there a specific chemical that is supposed to cause problems?

  99. I was hoping to find something here about what I’ve been seeing, but I don’t think these any of these describes my problem. My caterpillars (of any size) have been convulsing at the bottom of their cage until they eventually die. They do kind-of turn black, but only after death, and their bodies do not “deflate and ooze”. I raise on individual leaves in fruit fly rearing cups, and have never had this problem in the 5 years I’ve been doing this.

  100. Hi, Tony and all contributors out there! So much good information! Just wanted to say thank you, and to those writing in with problems: don’t give up! We’ve had our share of problems too, and it is discouraging. This year, we have scrupulously followed a cleaning and milkweed renewal regimen, and have released 75 monarchs with 100% healthy survival! We only have one mesh enclosure, so we collect 5 or 6 eggs at a time, to raise enclosed. The rest, we leave in the garden. I know the survival rate isn’t great “out there,” but we do see cats, chrysalids, and butterflies in the yard. We live in Central Florida and grow tropical and swamp milkweed, and asclepias tuberosa. Whenever the plants are vacated, I cut them down to re-grow. I make cuttings from the best stems, and rinse them in a mild bleach solution before setting in sterilized soil to root. The enclosed cats get the sterilized plants, and we’ve had no problems with these. This was the first year that Queens also showed up. I took a few of those eggs into the enclosure too (when the Monarchs were done), and it was fun to see them develop. I thought it best not to mix the Queens and Monarchs, because the Queens seemed like aggressive little buggers. Thanks again; raise on!

    1. great to hear this Chris. You have embraced a strategy I wish more raisers in your region would follow…setting limits and sticking to them. It’s difficult to say no, but essential for raising healthy monarchs. congrats!

  101. I, too, am in Southern California. The last “crop” of Monarch caterpillars I raised all died at various stages of growth. I raised them from eggs, indoors using floral tubes in clean cages. They did not have any of the symptoms described in your article, no vomiting, no parasitic evidence, buying milkweed from reputable sources, nothing to give me a clue as to why. Prior to that last group, I had phenomenal success with over 100 releases using the same rearing techniques. I’ve since carefully sanitized everything, cut milkweed back, all the appropriate measures so I’m cautiously hoping for better success in the future but wish I had some clues about the considerable number of losses.

    1. Hi Chris,

      Your experience sounds like mine. I am also in So Cal (Padadena area) and also just experienced loss of nearly and entire batch of 30 cats. In my case they were raised from eggs indoors, in a clean cage, and yet nearly all showed OE infection. Some were not successful in forming chrysalides, most emerged with deformities, and some did not emerge. This was after raising 30 healthy butterflies earlier in the season. The only cause I can think of was reusing the cage without bleaching between batches of cats. I did let the prior butterflies emerge in that cage (I wasn’t moving the chrysalides out), and then used it for the batch of cats. Perhaps the OE spores can last a few days or weeks ? Needless to say, I’m disappointed and more than a little spooked about raising more. I think our disease prevalence in California has to do with the drought. Everyone I have talked to this year has seen many, many tachnid flies and cases of OE, a very few healthy butterflies 🙁

    2. I have a newly emerged butterfly that has gotten stuck in a large amount of meconium, infected?

    3. I had a similar situation. In Venice, Southern California. The first batch in May, only one monarch emerged healthy. The 2nd June/July around 15 released. Then this week, only one out of 13 survived. They were deformed and some didn’t completely emerge. The cats acted strangely too. Cat fights! They pupated early & the chrysalides were smaller than the healthy group but the raising technique was exactly the same. It is a mystery and so sad to go through all the stages only to lose them all. Dehydration may have been the the problem but it was just as hot in May as July . I rinsed new milkweed every day. I’ve observed an unusual amount of wasps eating the milkweed and hundreds of milkweed bugs devouring the seeds and plants as well as small pesky flies. Now in September there are no Monarchs to be found in my garden although I have spotted a few in the other gardens. Any other suggestions appreciated.

  102. Hello,
    I am raising Monarchs for the third year. This year has by far had the most disease and death. I live in Southern California and am wondering if our drought has something to do with this. I have a caterpillar now who is in a U shape instead of a J shape. Is he sick and should I take him out of the cage before he spreads disease? Thank you for your help and comments!

    1. Hi Allyson, if monarchs are getting inferior milkweed (or not getting enough) because of drought conditions this will stress them and could negatively affect their health. The hanging U shape is more indicative of NPV virus so I would monitor the caterpillar. If you have a second cage, I would move any remaining caterpillars so they don’t get sick too. good luck!

  103. I’ve successfully released a number of monarch butterflies, but I have one chrysalis that is well past its “due date”. It has turned dark black now, though I don’t see any other signs of anything wrong. Any hope for this little guy? Or is he a goner? Any theories as to what went wrong? He had two friends who successfully made the jump from chrysalis to butterfly in the same cage, one a few days earlier and one a few days later…

    1. Hi Jay, if you mean the chrysalis has turned completely black the monarch probably has a virus like NPV and will not emerge. If the chrysalis has been transparent for days, the butterfly is either stuck or it did not make it. You could always try to open the chrysalis, but it’s unlikely the butterfly would be healthy. Congrats on your healthy releases!

      1. Thanks for the quick reply, and for all the information on your site. I will give the failed chrysalis an honorable burial, and hope for better luck and more successful releases next year!

  104. Question: How long should it take for the monarch to come out of its chrysalis? I’m on day 10 and I’m not sure if it’s still alive :/

  105. Hi Tony,
    Could you recommend the easiest cages to raise the cats to butterflies?
    At this time, I have three chrysalis in individual plastic boxes
    and the other two remaining cats are eating like crazy. One seems almost ready
    to leave the box.
    Again, many thanks for all the wonderful info you provide on your website.

  106. I RINSED MY MILKWEED WITH TAP WATER. NEVER AGAIN, IT KILLED 8 CATEPILLERS. THEY BEGAN SPEWING A GREEN LIQUID. SRANK IN SIZE AND DIED. SO NEVER USE TAP WATER. I WILL NEVER RINSE AGAIN. JUST INSPECT THE MILKWEED FOR BUGS AND SPIDERS,

    1. Hi Leslie, sorry about your caterpillars but it is not from your tap water. Spewing green liquid is a symptom of pesticide exposure. Any pesticide spraying in your area recently? New milkweed plants? Rinsing milkweed with water washes away bacteria and potential OE spores…I’ve done it for 35 years with no issues.

      1. You may have relatively decent tap water but Tony I’m telling you, tap water in this country is barely safe for humans, I can’t imagine no one has ever lost a delicate little monarch cat from rinsing with their tap water instead of the only safe water I know of–distilled. My cats got very sick from the tap water at my old house in central Florida. Took me a while to isolate the source until I stopped using tap water as an experiment and they stopped getting sick, then the one and only time I slipped up and gave them tap water again after moving to Indiana and immediately they got the exact same diarrhea (an understatement really, they were leaking watery stools all over the house for 3 days, every time they got up or sat down). They are half Bengal and I’m told bengals are more sensitive to new world contaminants than average N American house cats. I’m only saying this because we are kept in the dark about exactly how toxic many of the contaminants in our tap water really are, and not all municipal water is created equal, so I think it best if people make a habit of rinsing their milkweed with distilled water. I wouldn’t be surprised if pesticides have made it into our well water here where I live in rural southern Indiana surrounded by corn and soybean fields, including two roundup ready cornfields behind and in front of our property.

        1. Hi, it’s sad to hear that tap water in some regions could have that many contaminants…I’m glad you were able to figure out the issue. Their are always some ‘regional’ issues raising monarchs that most others don’t have to deal with…

  107. That’s a good question. I don’t know because
    I placed each caterpillar in its own plastic shoe
    box that I cleaned often. After they stopped eating
    and seemed to be unhappy roaming around, I
    thought they had the NPV and brought them back
    to the bathtub where the boxes were. Somehow they liked
    the doilies. Then, I learned that they need to be on top of something
    to make the chrysalis so I put the doilies back on top of the boxes.
    And, so far after the ‘J’ formation, two chrysalises appeared this a.m. although one
    seems smaller than other. (Is that a bad sign?)

    I’m such a novice in this whole process. When I lived on Cape Cod and grew butterfly/hummingbird
    gardens for 23 years, the habitat itself produced lots of caterpillars to butterflies.
    This is my first venture being a foster mom!!

    1. Hi Allison, raising is a lot simpler with a good raising cage that is escape proof and easy to clean. If you are having issues raising, I would consider a new set up for next season:

      Caterpillar Cage Ideas

      As for one chrysalis being smaller than the other, sometimes they are just smaller. If the chrysalis starts to get dark spots you could have an issue with parasites like tachinid flies. At this point, all you can do is monitor…good luck!

  108. Hi Joy, so sorry to hear this. Check the floor of the cage. You should find either white tachinid fly maggots or red tachinid pupae which have emerged from the chrysalis. Those monarchs will not survive. Make sure to dispose of the tachinid maggots/pupae.

    1. Oh my goodness!! I have been putting a clean paper towel in the bottom of the huts when I cleaned. When I took the paper towels off this morning, there were the red tachinid pupae!!! Does that mean all of the chrysalis are doomed? I did have two butterflies that emerged since yesterday!! When all the caterpillars went to the top to go into their chrysalis, I just left milkweed in the hut that looked fine. Just trying to decide when this happened. So sad!

      1. Hi Joy, just because one monarch has parasites doesn’t mean the others will. The eggs are layed inside the caterpillar by the adult tachinid fly. Just squeeze maggots/tachinid pupae in paper towel (or put them in plastic bag) and discard. Good luck with the rest of your monarchs!

  109. A couple of weeks ago I was thrilled to say I had 28 chrysalis and was hoping to be able to release them all. Seems though I’m having some issues I hadn’t had before. I moved 3 chrysalis to a separate hut thinking they were almost ready to emerge. They have not. Noticed a couple of chrysalis still hanging that have a small string hanging from the bottom of the chrysalis. Does this mean anything? I know I’ve made a couple of mistake raising them but have been pretty diligent about cleaning their huts. Not sure what has happened. 🙁

    1. Joy, I am replying to your rather old question: See what Tony said under #1 Tachnid flies regarding the “string” hanging from the chrysalis.In the caterpillar stage it was infected by a tachnid fly. Its eggs have grown inside the caterpillar. Yes it is a bad sign!

  110. Hi Tony,
    Wonder of wonders!! I thought the four 5 instar cats
    had NPV or some other disease after they stopped eating
    and didn’t seem interested in finding a place to make a chrysalis.
    I brought them back to the plastic shoe boxes in the bath tub
    and placed paper doilies over the boxes since I didn’t realize
    paper towels were just as good. Lo and behold…I came back
    to discover that one had attached itself to the doily and had
    started to form the ‘J.’ I did the same for the other 2 boxes
    and woke this morning to find that they also attached themselves
    to the top and started form ‘Js.’ I have 2 more stage 2 instar cats
    at this time. Hopefully they will continue to eat and grow and make it
    to the chrysalis stage. I really appreciate all the info on your website.
    Many thanks!!

    1. Hi Allison, I’m glad the caterpillars have taken a turn for the better and toward the next stage of transformation…could there have been an issue with the cage you moved them from?

  111. Hello! A chrysalis hatched indoors this morning at 8am and looks totally normal. I hope to release it outside this aft. since it is warm here, about 75 degrees. A fairly large droplet of tan liquid fell to the botton of the container she is in. What could that be? It looks like a drop of spilt coffee. Was that from the chrysalis or it excreted that while in the drying out process? I hope it will be normal and ready to go. Flowers with nectar are in the bottom of the cage but it hasnt gone down there yet 4 hours after hatching. Thank you. I learned a lot reading all the comments and your articles

    1. Hi Smokey, that brown coffee is meconium, which is metabolic waste the butterfly excretes about a half hour after eclosing…totally normal! Butterflies don’t need to feed before they are released. In captivity, it often takes butterflies 24-48 hours before they will feed. They are more interested in finding nectar outside…good luck with your release!

  112. Hi
    Is there a way to protect my butterfly garden without enclosing it? I see many eggs on the milkweed and many caterpillars, but no chrysalis. I also see ants and live in South Florida so there are lizards everywhere which is why I am assuming no chrysalis. I don’t want to interfere too much, but would like to have the caterpillars make it! Thanks for your advice

      1. Thanks! We are going to try it. Would an aquarium with a mesh top work? Is that enough oxygen?

        1. Hi Kat, that can work but is not ideal. The recommended cages work better because you won’t be bothering chrysalises after they are formed. The mesh cages are entered from the side and you can still set the kritter keeper lid down when there is a chrysalis on the roof. good luck!

  113. This is my first year trying to raise monarchs. I read and read, and batch after batch of caterpillars would grow to full size, and disappear. I don’t know if they walked off or got snatched by the crows. Finally, I put up green plastic poultry netting (Home Depot) around my milkweed plants, and my caterpillars grew full size (actually, the small ones were disappearing too) and now I have my first chrysalis right on the netting, and two more just starting to spin their webs. It is very rewarding. There are now over 50 caterpillars of all sizes on my 12 plants.

    1. Hi Williams, sometimes the caterpillars crawl off to pupate. More often, they are picked off by predators. Poultry netting is a good option for raising outside, but there are still more disease problems partly due to excess moisture. I’m glad you found a way to deter the wasps and birds. congrats on your success….

  114. I have a rearing kit I set up with 5 reared cats and 3 chrysalis (not sure where they started tho). One of my Cats, whom I have named Sparki has been a strange one since his 5th instar. While the others would sleep upside down Sparki would always find himself sleeping upright with his head on a leaf or bent in half or even hanging by maybe 4 legs. He was always eating, growing, fat and brightly coloured so if figured he was just a weird dude. I do have photos. Well it seems he was having trouble staying awake so I separated him. However he set up on a stem, didn’t work vary long on his silk pad (My other guy Spot must have spent 6 hours making his silk pad), maybe 10 mins. I found him laying upside down curled up on the floor against a stem. I thought he was a goner, but nope it seems that is his version of a J and he has made only a single thread to hand on to. Is he sick or just a little weird?

    1. Hi Becky, I’m sorry but it sounds like he may have a disease like NPV which is explained in the post. He is probably not going to make it, but you can isolate and monitor. good luck!

      1. I isolated him and he has continued on the the chrysalis stage. His chrysalis is formed ok but it is noticeably smaller then then other chrysalis I have that formed the same day. I would prefer he pass on from natural causes he is no where near my other guys tho. What happens if he doesn’t pass on in the chrysalis stage? I don’t want to release a diseased butterfly, after all I’m trying to raise these guys for conservation not just for the heck of it. Is there a way to test a butterfly for disease before release? I paid good money to buy a kit and the bugs from a actual butterfly conservation place.

        1. Hi Becky, I purchased 3 caterpillars from our state fair and all 3 of the chrysalises/butterflies were noticeably smaller than the ones I raised from eggs. All 3 emerged as healthy butterflies though and were released last weekend. If a butterfly is weak and has problems holding on to the chrysalis, that’s a common symptom of OE. Here’s more info if you want to test the butterfly:

          Testing Monarchs for OE

  115. Hello,
    After about 10 days, the pupa is beginning to turn black superior to the lovely ring of gold nubs, and this afternoon I found what looks like a tiny brown tic-tac on the bottom of the otherwise empty enclosure. There’s also a small whole in the pupa. I know this is a stupid question, but is there no hope at all? Should I just incinerate the pupa and the tic-tac to prevent spreading any parasites and pathogens?
    (I know it’s a maggot and I know all is lost, I just don’t want to believe it!)
    – Christina

    P.S. I live in WI – when would be the best month to purchase caterpillars to foster and release? Is this something you advocate? Thanks!

    1. Hi Christina, welcome to the tachinid fly club :/ kind of a rite of passage when you start raising monarchs… Parasites can be avoided if you bring in eggs, but it’s easy to dispose of the maggots/pupae so I still recommend bringing them in if you can handle the potential disappointment.

      I think buying eggs/caterpillars is a good option if you’re not able to attract them to your garden. Wisconsin had good monarch activity this season, and hopefully that continues next year. You could always try planting milkweed, and if you don’t find eggs by a certain date, then order them. The first week of August would be a good cut off date, and then you could order some to raise/release for the fall migration

  117. Hi! I have recently discovered evidence of tachinid flies… by empty chrysalides and long strings… but my mesh enclosure is sealed (but well ventilated) and I can not find the maggots/flies! I should be able to see them, yes? Are my other caterpillars in danger? We have lost 2 caterpillars in j-hook and 2 chrysalides. About 40 remain (hopefully!) I think this is due to taking in larger caterpillars I collected from outside milkweed.

    1. Hi Vanessa, if you don’t see maggots, they have transformed into red pupae. They should be pretty easy to find since they are noticeably larger than frass…

  118. Hello. I found a monarch caterpillar awhile ago. It went into the chrysalis stage and has been that was for 14 days. Still hasn’t hatched and it still is black in some areas but clear to see its wings. I’m worried that it might be dead but when I bend it it bounces back and doesn’t smell rotten. I need to know if it will hatch or it’s already too late. Please email me ASAP!
    Thank you!

    1. Hi Ashley, the chrysalis will only be transparent for one day. If it is transparent for more time than that thew butterfly is either stuck or dead. Either way, it will not survive…sorry!

  119. I have had so much death lately, and I’m getting discouraged!! I started late in the season…. mid June and had great results!!! Released 34 butterflies. I did have death and came to the realization that not everyone is going to make it. But lately it’s been all death. Late July and August I only released 10 butterflies!!! I don’t know what’s going on. I know by reading it’s that damn fly & OE. And now lately dehydration!!! They are outside in a netted cage/habitat that I cover in Thd heat…. But I’m just sad lately. I don’t know what to do .

    1. Hi Darci, we raise ours in a 3 season porch so they are experiencing the natural environment minus excess moisture and harsh sun. It’s also much easier to clean the cage when it’s inside. You may want to think about a new set up for next season. For now, I would disinfect your cage and let it dry thoroughly before raising again…good luck!

  120. I have good success for the last 2 summers raising monarchs from caterpillars brought in from my gardens or ditch in a 19.5″x10.5″x 12″ tall glass aquarium with a mesh top that I keep inside (21 of 25 cats last year, and 8/8 this year prior to this week). I feed swamp milkweed cuttings from the ditch, cleaned and kept in small bottles of water covered in cling wrap held on with rubber bands. I had 6 large caterpillars and 10 chrysalises (attached to the top of the aquarium), when a friend asked if I could ‘foster’ 15 large caterpillars she found on her tropical milkweed. They had almost stripped her plant of leaves, and she is leaving on vacation mid-week. She brought the cats over two days ago, on the remains of her tropical milkweed in a large plastic container with holes poked in it. I moved them over to my aquarium, along with a bunch of fresh swamp milkweed and some of the tropical leaves, and when we went to bed, they all seemed to be happily munching away. The next morning was a different story, with many of the caterpillars motionless unless disturbed, some hanging off of leaves or draped over stems. Through the day, I removed 14 cats that seemed near death to a second container on swamp milkweed leaves (though none were seen to eat all day), and all were dead by this morning. Another cat was hanging on the top of the aquarium this morning and started to form a chrysalis (even though it was not in a ‘J’ form) but was not able to complete the transformation and was dead my midday. noticed that a few of the sick cats expelled a dark green or black liquid, including the one hanging on top. The other caterpillars in the aquarium (presumably the ones I already had) all seemed fine, continuing to eat and move around; 5 of them have gone into chrysalises and the final one is now a ‘J.’ I was heartbroken to lose so many caterpillars, and dread telling my friend of their demise. I thought perhaps the swamp milkweed from the ditch was tainted, or perhaps the cats were just too crowded, but it seems that (I assume) only the new cats were affected. I also have some smaller caterpillars in two other containers that are doing fine and growing well on the same milkweed. Could there have been a problem with the large cats transitioning from tropical milkweed to swamp milkweed? I brought in some small cats from my tropical milkweed, and they switched over to swamp milkweed with no problems. Any thoughts on what may have happened? I didn’t notice any signs of tachinid maggots. Thanks for any insights!

    1. Hi Deb, sorry to hear this. It sounds like (throwing up green fluid) they were exposed to pesticides from the ditch swamp milkweed. Unfortunately, this happens far to often. Otherwise, caterpillars don’t normally have issues switching between tropical and swamp milkweed when they are both pesticide-free.

  121. Our family has successfully released one monarch butterfly into our garden and our second has just formed his chrysalis. The color is much lighter than the previous butterfly’s chrysalis and it’s wrinkly and not getting that hard shell exterior after over 24 hours. Ideas?

    1. Hi Lauren, all you can do at this point is monitor and see how the chrysalis continues to develop. Some chrysalises are lighter than others and this is normal, but not sure why it wouldn’t be hardening. Hopefully soon…

  123. I had the first monarch emerge but only has one wing, He is still alive and inside in a cage. What do I do? Hate to kill it. Then had two more emerge a few hours ago. Still hanging there , guess not ready to take flight yet. I have food for them nearby. I also found another caterpillar. Not sure if this one will make it being so late, etc. I am new at this, first year. I have always cared for hundreds and hundreds of hummingbirds. Over 50 pounds of sugar a week making nectar. Sometimes more but this monarch thing is brand new to me but want to be able to be the best Monarch mommy but will need help at this. Next year I will be better prepared, God willing I will be able health wise to do these things. But what do I do with the monarch with one wing? He had a cracked chrysalis. And there is another one with a cracked chrysalis. He has not emerged yet. Hoping he is okay but just need to know what to do with this one winged Monarch. HELP! Thanks, Joan

    1. Hi Joan, if the butterfly is unable to fly, you could keep it, but if it’s weak it probably has a disease like OE and it would be best to euthanize. If you keep it, they can be fed from cotton balls dipped in hummingbird nectar…good luck!

  124. While pulling out some old milkweed, I found 11 small cats of assorted size. I added them to my enclosure which had two cats and 12 chrysalis. Today six are chomping away but another five little guys are crawling up the side of or just hanging on the side of the enclosure/not staying on the milkweed. Should I be worried about disease and euthanizing? Or wait a while and see what happens? I moved the ones that look healthy to the opposite side of the enclosure, but I don’t have a second cage for complete isolation. I have not had any problem with disease in any past years, so this is new behavior to me. All advise appreciated.

    1. Gail, there is always a risk bringing in caterpillars, but it is usually worth it. All you can do is monitor them, and isolate any if they appear sick. Good luck!

  125. My husband found me a caterpillar & he has been eating well up until today. I have him in a plastic cage & he crawled to the side farthest away from the milkweed & is just laying there. Does this mean it’s sick?

    1. Hi Rebecca, if the caterpillar is right side up, he may be ready to molt or pupate. If it’s laying on its side, there is something wrong with it. It’s up to the caterpillar now…good luck!

  126. Hi Tony. I have been raising Monarchs for several years and have been going through ups and downs through the years. I will admit that I have not read everything on your web page, so I don’t know if it has been covered, but it was during a bad time, when I had found caterpillars dying that I discovered a small blurb attached to another article and I found my answer as to why. It was an Aha! moment

    It wasn’t a virus or pathogen that was killing them. it was the topical flea and tick repellent that was on the dog. The caterpillars that weren’t dead were either writhing around, having trouble coordinating movement and/or vomiting green liquid. It affects their nervous system. Even with thorough hand washing, traces of it can still be on your hands and can be absorbed through the caterpillars skin. So now, I wash my hands and put on vinyl disposable gloves found at the local pharmacy before handling any plant material, caterpillars or chrysalises, and handle the caterpillars as little as possible. While I have lost some over the years, there hasn’t been a repeat of that.

    I used to use bleach to clean the cages but did not like the lingering smell, especially if I was not able to air them out for a day. It’s not supposed to be good for people, can’t be good for the caterpillars. So now, I use a 40% solution of Everclear grain alcohol for the cages and utensils and 10% – 15% solution to clean the eggs if they are suspect. I used the time frame used by butterfly breeders who use bleach, but you don’t have to be as exact. It can smell like a wicked party went on for a few minutes afterwards, but it dissipates fast. While I live in New Jersey and there is usually not a problem with Oe, I unfortunately had experience with it in butterflies that had been mailed to a group I belong to be used for an educational program and the chrysalises had to be destroyed, ( I prefer the freezer method – they are cold blooded and go to sleep from the cold before freezing) but of the eggs I took home and disinfected, I only had 5 chrysalises that I had to euthanize because they were suspicious looking. No spots, or specks or uneven coloring on any of the others. Perfect jade green chrysalises. So, I think it worked. I did pop a lot of the eggs off of the leaves or just left a tiny bit of leaf with the egg attached and put them on fresh leaves after disinfecting them.

    I hope this information helps anyone out there in their quest to raise healthy Monarchs.

    1. Thank you Heather…this is most helpful info. I’ve heard they can die from exposure to flea/tick treatments but have never seen this first hand. It’s always a good idea to wash hand before handling caterpillars…you never know what might be sensitive to their systems.

      and the everclear??…that’s a new one! Love hearing new ideas and what’s working for others. Thanks again for sharing. Have a wonderful rest of the season…

  127. I have a couple of questions. I got a monarch at the fair a week ago and it is getting huge. I’m expecting a chrysalis to happen any day now. But, it’s stopped eating the milkweed I’ve been bringing it from my backyard two days ago, (transplanted from my grandma’s house two years ago), and doesn’t move that much any more. I clean off the milkweed, (no soaps, just water), and try not to touch the caterpillar.

    A farmer that lives near by sprays Round-up on his crops. I haven’t spotted any green caterpillar puke. Is my milkweed bad for the caterpillar? And is the caterpillar okay, just shedding skin, (or not)? Two days of very little movement is concerning me.

    1. Hi Kirsten, it is possible the caterpillar is going to molt…Otherwise, I think your concern is valid about the milkweed source. All you can really do is watch…if you have another source of milkweed that you know is pesticide-free, you could try switching it out to see if that makes a difference. good luck!

      1. Found some pesticide free milkweed. Caterpillar has eaten some, but not a lot and still moves very little, so I’m still worried since it’s been three days. Still no green puke, poop is solid and blackish like normal. Something else I’ve noticed is that it’s ‘antenna’ (is that what they’re called?) are drooping way down instead of being perked up like I’m used to seeing. Does that indicate anything, (aside from maybe sleeping)?

        1. Hi Kirsten, I wouldn’t worry about the filaments on the caterpillars head. I hope your caterpillar is continuing to grow…good luck!

          1. R.I.P

            The little guy didn’t make it. Found him on the bottom, not moving, having shrunk overnight with no signs of a molted skin. I put in a fresh leaf and the little fella just rolled. No grip, no movement, nothing. The was a puddle of clear liquid by the head, (used a paper towel to check), but I’m not sure what the cause of death was. I’m assuming it was my milkweed. It ate the stuff from my grandmother’s house with no problem, but the day after I returned home and gave it some of mine, the problems started. I guess it was the Round-up.

            Sad. 🙁

  128. Hi Tony,

    I’ve had a pretty good year raising my Monarchs – unfortunately (kind of), I am traveling the first 2 weeks of September, so held off on aggressively seeking more eggs and little cats last month, but have released 29 beauties this year and have one in chrysalis and one munching away. My dog sitter gets to handle those 2 while I’m gone – who, I’m happy to report, is now a Monarch enthusiast and is going to start saving them next year along with me!

    Anyway – I went to a client’s home a couple months ago and the subject came up and I started to show her pics of my butterflies and she said she had milkweed in her yard and that she usually just pulled it out and threw it behind her fence. (I had to stop myself from rushing out there to examine it!). So – I went outside with her and started to examine all of her plants and THEY WERE COVERED WITH EGGS AND BABY CATS!!! Omg – a gold mine to me! So – she wanted me to take them which I did. Now the saddest thing ever – there were 8 total and the eggs hatched, but every single one of those cats died what seemed a terrible death. They would start spazzing/convulsing – curl up, fall off the leaf, etc. It broke my heart, but it didn’t affect all my other babies which was good.

    What the heck could that have been? I feel like they must have ingested poisons – pesticides maybe? None of them made it past the 2 instar stage.

    I love what you are doing.

    Thanks,
    Michele

    1. Hi Michele, so sorry to hear this. I’m with you, sounds like it was probably pesticides. Congratulations on the rest of your successful season!

  129. Hi Tony,
    I have Common Milkweed growing in several places around my house/garden. The 2 cats I found seem ok since their change to chrysalis form. Their green & gold cooking pots are so pretty! 😀 My son found another cat during their eating frenzy, but I decided to let nature take it’s course with that one. Haven’t seen it since. Bad choice! My question is this after reading all these posts. I too did not wash off my milkweed, or spray it while they were eating. The milkweed is never sprayed with chemicals, and the milkweed was cuttings in water. I’m just worried now that they might have been dehydrated. This is my first time bringing them in from the garden. I usually just watch the process out in the garden. Will let you know when they emerge. What is the best type of flower to have waiting for them? Also my milkweed has pods. I collected them last year and took them to my local nursery for a seed exchange. They said there is a freezing step they need to go through in order to be good seeds. Can you explain that? Thanks for all the wonderful, educational information.
    Sincerely,
    Susan from Maryland.

  130. Ah, sorry, Autocorrect kicked in. Helmet WAS hanging in his J shape yesterday.

  131. Just lost one of the cats this morning. Helmet (so named because his head case was stuck to his antenne when I found him) wasn’t into his J shape yesterday, but was hanging limp this morning and didn’t react when I tapped the jar. He’s much smaller than he should be, but he’s a fifth instar, and he was healthy as far as I know. I haven’t seen any evidence of parasites even though he looks like your photo of a caterpillar killed by tachinid larvae, and all the milkweed he got was collected from my backyard and washed before it was served. I don’t know what happened to him, but I’m worried I might have spread it to a number of the others because he didn’t seem sick and I would have been handling both him and the others since I’ve been tracking their growth. They all have their own jars, but if whatever-it-is got on my hands….

    Helmet’s “twin”, Dot, looks like she’s preparing to make her chrysalises, but she also looks a bit smaller than normal. They were found together as small caterpillars, so could she also be sick? And I’m also concerned about another cat who I hatched but is acting much like Dot but is a bit closer to the normal size. I think he’s fine, but I’m not sure. He hatched out before I found Dot and Helmet, but could he have picked something up? There was one day where I checked on him and his ” twin”–they had been laid on the same leaf and hatched just hours apart–and his twin was much smaller, though I thought it was because he had somehow been skipped during feeding time…

    I’m sorry for all the questions, but this is my first time at all this, despite the fact that for the most part, I’m having a lot of luck.

    1. Hi Kitt, sometimes small caterpillars can indicate parasitism (like tachinid flies) but sometimes it’s just a small monarch. All you can do is watch and hope for the best. It sounds like you are giving them all the best chance to survive. good luck!

  132. I recently had a monarch emerge with perfect wings, but the front legs were weak, spastic, and unable to hold the butterfly on the branch. I could only lay on its side. Any ideas what disease causes this?

  133. Hi Tony,
    I really appreciate all your posts and learn so much! My latest cat started hanging in J overnight. I’m concerned, because I’ve been reading your post about diseases and hadn’t realized the issue about hydration. So far, I’ve raised three other cats into healthy adult butterflies without spritzing the terrarium with water. I use a very thin (1/2″ diameter) glass vase for milkweed cuttings, so the leaves never get dehydrated. Do you think hydration could be an issue and what would you advise at this stage? It’s significant that this was very large for a cat when I found him outside and brought him indoors. He/she was only in the terrarium for a few days before hanging in J.

    My other question is that a very small amount of frass is on paper towels caught under the vase.I can’t remove it without moving the cat hanging in J slightly a couple of times. Should I just wait until the chrysalis has formed to clean that area?
    Thanks so much! Kathy in SE Michigan

    1. Hi Kathy, since you are using water cuttings, hydration is not likely to be an issue. I suspect most reports of butterflies stuck in chrysalides are OE related. Still, caterpillars love drinking water droplets off the leaves.

      When you bring in large caterpillars, it’s a gamble. but, many times it pays off. It sounds like you gave the cat the best possible chance to survive.

      If you can’t clean a section of the cage without disturbing the J caterpillar, I would wait. I’m not sure of you exact set up, but you might want to consider a mesh cage for future raising. It’s much easier to clean with the side opening cage door. Congrats on your success and good luck with the rest…

  134. Hi Tony,
    If one or both of the parent butterflies has OE is it assured that all of the offspring will have OE as well or is it possible for offspring to not contract the disease? If one suspects they have butterflies in their garden with OE and if one course of action is to “take a break” from rearing, how does one do that if the infected butterflies are out there laying more eggs? It doesn’t seem right to not bring the eggs in to keep them from parasites.
    Thanks

    1. Hi Chris, caterpillars get OE when they ingest OE spores…these can be on both milkweed and also their eggshells. Rinsing milkweed helps to remove spores.

  135. Hi Tony!

    First of all, this site is awesome! I’m 16 and caught the habit of raising monarchs from my older sister, but now that she’s moved out I’m on my own- this site has been so helpful in answering my questions, teaching me new things or just giving me monarch raising confidence!! 😉 Thank you Tony!

    I have one tiny little baby caterpillar, a little longer than my pinky nail, who is ill. Her name is Heidi and she was in one of my big mesh cages with the other cats but was just sitting, unmoving, at the top for a day or so. She seemed to be letting her head hang? Or to not be “holding on” with her front feet? I have her isolated now but she only moves when I nudge her with a leaf (to see if she’s still alive, honestly). Although she has managed to move herself off of the milkweed leaf she was laying on, on her side, and onto the slightly moistened paper towel that the leaf is on top of. I only left the towel under the leaf because I thought she was too weak to move off of the leaf, but it makes me think that if she moved onto the moistened paper towel that she must be thirsty? (Do caterpillars even get thirsty?) I really hope all this makes sense! 🙂 It’s just very odd to me because all of my other cats have been healthy (except one which had already pupated when this little guy arrived. I think she made her chrysalis too early because it looks “partly made” and is pretty dark, so I moved her into a different container in case of disease. She was perfectly healthy before making the chrysalis- just too tiny I think- poor baby!) So I’m at a loss as to what is wrong with little Heidi… Have you had any experience with this? Maybe it’s just nature?

    Oh! I’ve also gently brushed the edge of a moistened paper towel over Heidi’s back- which sounds SUPER weird I know- but it seems to perk her up a bit for a while afterwards. Do you think this is a good idea? It seems so odd to me but maybe it’s helping?

    Thank you for any advice!

    1. Hi Andrea, this sounds like NPV which is a monarch virus…check out the description on the post and there is a link to more info. Sorry to say, you will have to euthanize this caterpillar and then disinfect your habitat. I hope the rest of your monarchs are healthy…good luck!

  136. Hello! I raised five monarch cats for a long time, and left them in a small box in my bedroom while I went on vacation, knowing they wouldn’t hatch until at least the last day I was there, so when I came back I could get them safely outside and into the world. Well, the catflap in my room was left unlocked, and as soon as my beautiful butterflies hatched my cats attacked them. Each was found dead. I had a final one in a seperate jar who has not hatched. I never got to take the milkweed out before he began to form a crysalis, and now there is mold growing on the bottom of the cage. Will he be okay? Thanks!

    1. Hi Caitlyn, so sorry to hear this. But, we have all made raising mistakes and they all make us better raising future monarchs.

      For your remaining chrysalis, all you can do is switch jars and monitor it. Excess moisture is not good for monarch development, but I don’t know if it will affect this butterfly or not. We use mesh cages and kritter keepers which allow better air circulation. Good luck!

      Monarch Caterpillar Cages

  137. I was out collecting milkweed this morning, inadvertantly coming back with five little cats and an egg(which may have been layed by my first released butterfly! But that’s beside the point). I’m worried about the smallest one. He–or she–appeared to have been hurt in some way, since his back half looked crippled and smaller than his front half. I brought him in, and he seems to be doing fine now, since he’s still eating and able to twitch his back end, but its color is slightly off and his body overall has a slight lightning-bolt look to it. When I found him, his back half was hunched up like he was crippled, but it seems to have expanded back out a bit. He’s isolated from the other 45 cats and chrysalises, and since he was on a low leaf I put more food in for him that didn’t have dirt on it. The other two cats I found on the plant were fine, but I’m not sure if this little one will make it. Any idea what’s wrong with him? There were ants tending to aphids on the same plant; could one have attacked him?

    1. Hi Kitt, aphids don’t attack monarch caterpillars but there are lot of other predators (like ants) that do. You did the right thing by isolating and monitoring. I hope the little cat recovers…good luck!

      1. Update! The little crippled cat I found has since gone through a molt or two (I have no idea what instar he/she was when I found him/her, but he/she’s now in the fifth one) and has made a full recovery! Other than an odd black stripe running along his/ back end starting about halfway down–the point where he/she appeared to have been injured–there’s no sign that anything had ever happened. Looks like soon I’ll have another beautiful chrysalises, and then an even more amazing butterfly to release–hopefully with a little tag attached!

  138. Hi, my monarch just made it’s chrysalis. It is nice and green and looks like the pictures, accept there is what looks like a hunk of skin hanging off one side. I know they shed their skin, but I can’t find any pictures that look like this. Does it mean something has gone wrong? Thanks!

    1. Hi Alissa, that is probably just the shedded skin of your caterpillar. You should be able to remove it or you can just leave it. congrats on your chrysalis!

  139. over the last few weeks I have seen several 4/5 instar Catapillars on my milkweed. Today I decided finally to bring one inside because we raise chickens and I think they are eating them. I believe this one is a 5th instar. I watched it all morning eating away at the milkweed just fine. I got out an old reptile aquarium with side doors and a screen top, lined the bottom with paper towels, put a long stick in there diagonally from top to bottom. Then I clipped a few leaves off of the milkweed plant, rinsed with cold water to remove the aphids and put them in the cage. Then I clipped the leaf my friend was crawling on and convinced him to transfer onto one of the washed leaves and put him inside the cage. The cage is on the kitchen counter not in direct sunlight. It has been 6 hours and he hasn’t taken a single bite. He did crawl up to the top of the cage and he just sits there upside down on the screen (not hanging off, all legs are on the screen). Did I traumatized him by bringing him inside? I do have ac and its 72 in the house but it’s cool and rainy/windy outside today. Is he just in shock? What can I do?

    1. Hi Stacy, it’s possible the caterpillar is about to molt or preparing to form its chrysalis. You don’t need sticks for them to pupate…the caterpillars should be able to pupate from the screen top. It sounds like you are doing everything right on your end…Good luck!

  140. I found my sole caterpillar limp on a leaf with a black goo coming from around its mouth area. I suspect black death, but the cat was eating well just last night and had made no attempt to crawl to the top of the cage. Do you have any thoughts on the situation? Thank you.

    1. Hi Meg, sorry to hear about this. Viruses and bacteria can be passed on milkweed if it’s not rinsed well with water. Also, if you recently purchased milkweed, are you sure the plant was pesticide-free?

      1. It was from milkweed grown in a backyard garden area. To my knowledge, no pesticides were used around there. Since then, the black goo had started coming from the other end of the caterpillar as well and it has died.
        Do you know if it is possible to save a caterpillar once it has been infected with some virus, poison, or parasite? Or are they too far gone once symptoms show?

        1. Hi Meg, that definitely sounds viral/bacterial. If that’s the case there is nothing you can do to treat it. Sorry again for your loss…

  141. My sister and I have recently started raising monarchs over the past few weeks indoors. I’ve released 7 butterfly’s so far, have about 13 more in chrysalides and about 20 more still munching away. I just noticed today that one hung it’s J under a milkweed leaf and the caterpillar seems awfully small to be in its J shape already. I would say half the size of the rest that have hung. Should I expect this one to not make it? I feel horrible that maybe it would have had a better chance if left out in its natural habitat? It just really looks too small yet to be ready to form a chrysalis. Any information is much appreciated!! (I’m in Wisconsin and we found all eggs and caterpillars at a local state park, they do not spray w chemicals of any kind). And I get fresh milkweed every day or every other from areas that are not sprayed also. Thanks in advance!!

    1. Hi Tammy, it’s estimated between 1-5% of monarchs survive outdoors so never doubt you are helping the population by raising some indoors! If you bring in caterpillars there are more risks for disease or parasites, but if the caterpillar seems sick, just move it to a separate cage and monitor.

      It’s possible the caterpillar has tachinid fly parasites. If this is the case, it would die anyway. It also might just be a small butterfly. Allow it to pupate. If it has tachinid flies a couple maggots and/or pupae will emerge and fall to the cage floor. Just pick them up and discard. They are not a threat to your other caterpillars. Good luck!

  142. Just a quick question, I have four caterpillars that I am raising, I have one on the top of the container that has attached to the top, with it’s silk but it’s not hanging upside down. Is it ok? I’m new to this so I’m asking.

    1. Hi photobug, first they form the silk button, and then they hang themselves from it. I hope this is how things worked out for your first caterpillar?

  143. I am so sad! This week I lost an entire container of precious cats. They were all different sizes. They all turned about a shade darker. Some just laid on the bottom, and simply died! And others started climbing up the walls and folding themselves completely in half, hanging by a few feet until they dropped, some writhing. All stopped eating and they were all dead within 36 hrs. Now another container is doing the same. I lost 12 today. After 5 years of about 60 per year I have never seen this. My cages all have screened tops and I meticulously cleaned daily. Also I cleaned and dried my milkweed. What happened?

    1. Hi Shannon, so sorry to hear this….sounds like NPV which is a very contagious monarch virus. I’m not sure where you are located, but NPV is more common in continuous growing regions like Florida and Southern California.

      Before you start raising again, throughly disinfect your cage with a 10-20% bleach solution. You can also take the extra precaution of rinsing milkweed leaves with a 5% bleach solution, although we don’t do that in our northern region. Good luck!

  144. I have been raising caterpillars for a few years now, and now I have about 20 cats and I keep 1-2 in their own jars. The jars have ventalation and I clean them out 1-2 times daily. I have never had a problem in the past with this method. I collect all my cats while they are eggs. They are all healthy and growing nicely, however I have one that has a yellow head and yellow legs. The rest of his body is normal and he appears to be healthy. He is eating and growing normally. Is there something wrong with him? If there is, what should I do to help him or to prevent this?

    1. Hi Julia, unless the caterpillar appears sick or is spitting up green/black fluid I wouldn’t worry about this. It sounds like you already have it isolated if you raise one to a jar, so continue to feed, clean, and monitor. good luck!

  145. Hi Tony!

    So it seems as though I have “Black Death” Noooooo!!
    This is my second year of raising Monarchs. Last year I did two sets. First was 8 and the second was 16. (from wild milk weed that just popped up in my garden) I raised them all from eggs. I had a 100% success rate.
    This year I planted 12 milkweed plants. I have my first batch of 15 to chrysalis stage, and a second batch of 18 in 2/3 instar. Both batches are a mixture of eggs and a few caterpillars that I found while harvesting milkweed leaves. I had 8 in chrysalis and 4 hanging J’s and three still munching when I noticed on of the hanging J’s oozing black goo. Then a second J started to turn very dark. A third hanging J did turned into a deformed cocoon. After reading your helpful information I am hoping that I will get the last 2 cats to Chrysalis. I immediately removed the black cats, using gloves and washed as much of the container as I could. I trashed all my milk weed from all the containers and replaced it. I have two cats from the first batch of 15 left to go.

    My question is how do I know if I have stopped it? I had a visitor to my milkweed yesterday. Now there is about 20 new eggs out there. I am nervous about bringing them in and rearing them only to find out it is on my milkweed. I cannot wash the leaves the eggs are on.

    My method of raising: cut the leaves off the plant that has eggs. Wrap the bottom stem with wet paper towel and saran wrap. Once the leaf dries out or is munched away I replace it with a new leaf wrapped in the same manner. I harvest the leaves from my yard while I can and last year went to the local ditch to have extra when I felt I was running low. Once the cats are to the 3 instar I usually have to replace the leaves once a day. I empty the frass and wash and clean the container. (shoe box sized plastic containers as well as disposable plastic veggie tray containers with five individual sections.) I usually wash the milkweed leaves because I always have a ton of aphids. (Lots of lady bugs this year as well:))

    This year I did the same thing except I started using one dishtowel to dry my leaves. Last year I used paper towels. I also just emptied the frass out of the container and wiped it out with a dry paper towel. No washing. I feel that this is where I went wrong. I have reverted back to my old method.

    I just do not know at what point I will know if my cocoons are sick, My second batch of 18 cats are sick, and should I even attempt to bring the eggs in? Feeling a little broken hearten. Any help would be welcomed.

    1. Hi Amy, sorry you are having disease issues this season….that is always disappointing, to say the least. First off, I raise on stem/leaf cuttings so our cats are never crawling around in frass. I also don’t “dry” leaves…just shake them off after rinsing.

      If you want to learn my exact process for raising check out Raise the Migration 3 which starts on August 15th:

      Raise The Migration 3 Info

  146. Since 2007 I’ve raised probably 3,000 monarchs. With the exception of one year with a strange batch of butterflies, my survival rate has been about 97%. Just yesterday I ran into something I’ve never seen – a dead, fire-engine red 2nd instar. The other 2nd instar on the same leaf is in quarantine and the balance of that group of cats has been moved into a new container with new food. This cannot be good. Have you ever had a cat go red? No fluids were expelled.

    1. Hi Michele, that is odd…I’ve never even heard of this happening before. I will be sure to update this comment if I come across any info. I hope this is an isolated incident!

  147. I’ve never had so many issues before as I’ve had this year. Not many of my caterpillars survived, and for the ones that did, all seven that made it to a chrysalis had a deformed one. All of them are not very well closed together and near the top 3 pairs of their legs as caterpillars seems to have become part of the chrysalis. It hasn’t been 14 days yet, so i don’t know if any of them will hatch or not. I brought all of them in around the same time when they were newly hatched caterpillars. I wonder if it’s a disease from the milkweed leaves, but they were from the garden, no pesticides, and the deformation was the same on all of them. Do you know anything about this?

    1. Hi Claire, so sorry to hear this! It sounds like severe OE infection or maybe a bacterial/viral disease. The prognosis doesn’t sound good for your chrysalides, but you can always monitor and see what happens. Cleaning milkweed and cleaning up frass can go a long way in disease prevention of monarchs. If you are interested in learning how to raise monarchs to release for the great migration, make sure to follow along with Raise the Migration starting mid-August:

      Raise the Migration- Raise Monarch butterflies

  148. Hello,

    Thank you for having such an informational site. I’ve learned a lot from it! I recently bought a cage to raise monarchs indoors because I couldn’t stand watching wasps eat my babies (they’re vicious!). I brought 8 cats in when they were fairly large, they all hooked, formed chrysalises, and emerged just fine. Unfortunately 2 came out and weren’t able to fly. One I think was stung by a wasp before I brought him in, the other formed with her upper wings slightly darker and smaller than normal. They dried nice and straight. She’s trying hard to fly but only makes it a few feet straight to the ground. It breaks my heart. I hope I don’t have OE. Do you know what could be causing this?

    1. Hi Lauren, when you bring in large caterpillars there are always more heath risks from being exposed to bacteria/viruses to parasitism. You’ll typically have more success bringing in eggs or small caterpillars.

  149. Hi Tony,
    I ordered 20 cats online & received about 28 which was a nice surprise. Two didnt make it, but the rest were all doing well & 19 made it to chrysalides. Maybe because everything seemed fine to that point, I didn’t pay as much attention to the remainders until suddenly noticed all basically had stopped eating & weren’t moving around much. I kept giving fresh milkweed & they seemed interested walking around on it but still no eating. Found two limp on their side, the rest have been lingering past 2 days. Not sure what went wrong. I dont think they will be around much longer but dont have heart to dispose of them til sure they’re gone.They are still in same castle as 19 chrysalises. Any thoughts would be appreciated. Thanks

    1. Hi Sharen, so sorry to hear this. Based on the info you shared, it’s hard to say what the exact issue is…you would need to have the monarchs test for diseases for a conclusive answer. In order to raise with a high success rate, it helps to follow a good system that prevents diseases. Regular cage cleaning, an easy to clean habitat, and hydration of caterpillars are all things that can make a world of difference. If you are new to raising, I would suggest keeping the head count under 10 to get a good feeling for the process.

      If you are interested in learning the step by step process we use for a consistent 95% survival rate, check out my raising guide. Otherwise, there are also some other good resources here to help you along your raising journey:

      Raising Resource Page

  150. Hello,

    Thanks for the information. I have 12 chrysalides and 1 turned clear in less than a week. I can see the monarch wings and it looks fine, just maybe smaller than normal. Do you know why? All the others are still green and look healthy.

    1. Hi Jennifer, a week is typically the earliest a chrysalis should turn transparent. If you brought in the monarch as a caterpillar tachinid fly parasitism is a possibility. But, if you can see the butterfly inside, it might just be a small butterfly…I have raise a few over the years, and they’ve all seemed healthy otherwise. Good luck!

    1. Hi Nancy, monarch diseases are not always fun to learn about, but the more you know, the less you have to deal with them. Hope things are going well in your garden this season!

  152. Hi Tony,

    My husband and I got our first milkweed bush and the first round of a few monarchs went really well. Then we had 18 baby caterpillars!! We watched them grow and eventually most moved away from our planter. About three caterpillars started the chrysalis process (I think) on the actual planter, and then one started on our brick house. A few days later, all 4 were still hanging, in no cocoon and most looked flattened (possibly dehydrated). They still hang, and I have no idea what to do or what went wrong! Please help. I am very sad these little guys didn’t survive…. I took pictures if you would like to review. The milkweed bush is outside in Ventura, CA.

    Thank,

    Shanon

    1. Hi Shanon, it’s estimated that between 1-5% of monarchs survive outdoors, so you were lucky to have a successful first batch develop without issue. All regions have predator problems…common predators include wasps, tachinid flies, spiders, stink bugs, ants, and the list goes on…

      You can boost their numbers by bringing a few inside to raise…

      1. Thanks, Tony. Good to know. It was a bummer to see 5 or so of our little caterpillars hanging lifeless but I guess that’s nature. I’m nervous to bring inside since we have two cats. We also found these tiny little aphid type bugs on the plant today. Do you think that’s the culprit ? Any natural remedies to rid of them ? We will buy a new milkweed plant and move the eggs inside , give it a try !

  153. One of my caterpillars is laying on her side, she wiggles a little but not much. I lost 8 others over night. Now this one is acting strange and I have another in the middle of the molt who threw up green all over the paper towel when he fell off the leaf. Was he startled or is he sick? I isolated him and the other one who is laying on his side. I am scared. I have lost almost half of them in 12 hours and I don’t know what I am doing wrong.

    1. Hi Raely, so sorry to hear about this. It sounds like a pesticide issue from what you are describing. Have you recently purchased milkweed plants?

  154. Am new to monarch butterfly raising. I have caterpillars in different phases however I recently harvested 2eggs and this morning they look purple. None of my caterpillars have been hatched indoors all have been hatched from the plant with the exception of these two.

    1. Hi Alia, monarch eggs do turn dark on top before they hatch (it’s the caterpillars head about to eat through the shell) but I have never seen or heard of an egg turning purple before. Here is a photo of the egg when it starts to hatch:

      Monarch Egg hatching

      1. What do these behaviors mean:
        1. Raising head in a jerking motion like a nervous tic (not the I’m looking for a new milkweed leaf look) is it a defensive action because I’ve gotten too close? I’m worried it’s illness…
        2. Both front and rear antenna moving in unison as if waving, very adorable!

        1. If they only do it when you’re close, most likely a reaction to your voice or another noise.

  155. hi, I had a butterfly come out of its cocoon today and it came out with its two front legs only and a little bit of one back leg. It didn’t fall off while coming out and I didn’t see it left in the cocoon. what could’ve happened 🙁

    1. Hi Ana, it sounds like your butterfly didn’t develop properly. This is unusual but not unheard of. I’m not sure why this happens, but if you focus on disease prevention (ie daily cage cleaning, and offering clean, fresh milkweed) issues like this are few and far between. Good luck with your future monarchs…

  156. Hi, I had 24 caterpillar from my plant, and I brought it inside, and I feed them all. Out of 24 20 caterpillars made it. My question I had a few that it seems they were week when they hatched they had fall or they couldn’t unfold the wings properly. They are still a live, but if I keep them they will die, If I let them go, they won’t survive long :(. what happend if they get wet …. do the wings dry fine this time?

    thanks

    1. Hi Arlette, this is a classic symptom of OE disease. These butterflies should be euthanized or kept inside (isolated from other butterflies) until they expire. OE can be prevented by proper cage cleaning and rinsing of milkweed.

    2. What do you mean by “they had fall”? I just had one hatch today and looks to have left some brown residue underneath in the cage. Although he seems to have formed well and his wings unfolder properly.

  157. Hello. I’m wondering if we’re doing something wrong. Our cats don’t seem to be able to make it to the chrysalis stage. They die before they change. What could be causing this? They are fed on washed milkweed, their container is cleaned at least once a day, but they still keep dying. We have lost 2 so far. The first just turned black. The most recent one was found on the side of the container in a U shape, silk all around. I took a leaf and gently transferred him to a different container hanging from his silk. He got active briefly yesterday afternoon, but now he isn’t doing anything but hanging – and not in a J shape. What are we doing wrong?? These cats came from a mail-order place, so I don’t know their history. The newest ones we found naturally, and we don’t want to lose them all. Please help!

    1. Hi Angie, it sounds like your caterpillars could have a bacterial disease or virus. you might try raising them in separate containers to insure some survive. I would report this to the vendor you bought them from, to see if anyone else is having similar issues. Good luck!

      PS…make sure the mail-order monarchs are separate from the ones you found outside.

  158. Hi Tony,
    I bought a milkweed plant from Home Depot which had a monarch caterpillar. I took it home to my apartment and for the next couple of days it was eating and growing, it seemed to be ok. On the third day the caterpillar stopped eating and stayed in the same position for long hours. I was expecting for it to pupate and turn into a chrysalis. Unfortunately, the next morning I went to check and it did not pupate successful. Apparently the caterpillar was starting the pupation stage when it died. 🙁 :'( I was so sad.
    This is the first time this happens to me, I’ve raised a monarch larvae in the past and they all grew into adult buttterflies. Would you know what could have been the causes that it died?

    1. Hi Maggie, it’s not uncommon for big box stores to have milkweed that has been sprayed with pesticides. However, the caterpillar typically throws up a greenish fluid if this is the case…perhaps it was low levels. The caterpillar could have also had a parasite like the tachinid fly. You would have seen a maggot or red pupae on the ground. You might want to find a local nursery that you’re sure doesn’t grow milkweed with pesticides. Good luck!

  159. This has been a very disappointing Monarch season for me. Last year at this time, I brought in 35 crysalis and lost only 2 or 3 butterflies.
    This year, I found only 13 caterpillars, and only 5 made it butterflies that could fly. The caterpillars looked good, although a couple looked a tiny bit thin, but healthy looking when they made their crysalis. And all their crysalis also looked fine.

    However, one problem after the next affected the butterflies so that they died, or couldn’t fly and then died. The first one that emerged looked good. His wings looked nice and straight. I would have let him go that day, but had to drive across town, so I planned to release him the next morning. That night he looked fine, but the next morning his wings looked slightly curved. They weren’t bad, just a slight curve, but he could not fly, so I could not release him. I kept hoping he would get stronger, but he could never get off the ground.

    The next butterlfy that emerged was about 2/3 the size of other Monarchs. He looked fine, just noticably smaller, which I have not seen before. I released him and it appeared he could fly. The next one that emerged looked fine, but I found him dead that evening. I couldn’t find anything wrong with him. I took 3 more outside and left them in a “butterfly castle” to fly away when they were ready. 2 flew away, but 1 was found dead still in the castle the next day. His wings looked fine but his body seemed thinner than other butterflies. Several butterflies were found with crumpled wings. I found one on the bottom of the castle. It looked like he had gotten trapped between the net castle wall and a piece of paper towel. Most of the butterflies I’ve had before would have easily been able to pull themselves up, but it looked like this little guy couldn’t.

    Another butterfly was found with his back end stuck in the crysalis. I cut him out but his wings apparently dried 1/2 way folded so they never straightened.

    Of the last 3 butterflies that I took outside, only 1 was able to fly immediately. 1 fluttered over to some plants and sat there for at least 5 hours (I was outside working in the yard and checking on him periodically). After a full 5 hours, he finally took off, circled me and landed in a tree. I hope he was able to fly well after that. The other butterfly tried his best to fly, but just fluttered all over the ground. I would put him on a lantana flower for some food and he would look like he was eating, but if I wasn’t propping him up, he would fall off the flower, all the way down to the ground. I sat out there for a looong time holding that butterfly up to flowers trying to let him eat thinking he get his strength and would be able to get off the ground. But he never did. It was so sad watching him try so hard, and just fluttering all over the ground like a moth. He finally died after 6 or 7 hours of trying to fly.

    So, out of the 13 crysalis that I brought in, only 5 made to butterflies that could fly. It has very dissapointing and sad. I am wondering what in the world happened.

    All of the caterpillars came out of the same milkweed patch and were about the same age (within a few days). I am wondering if the same female could have laid the eggs and perhaps she had encountered a pesticide that effected their growth? (I know some insecticides have growth inhibitors that affect the life cycle of the insect). Since there was something wrong with so many…. small size butterfly; bodies that looked too thin; can’t fly even thought their wings look fine; die for no apparent reason after emerging. It is just so puzzling to lose so many.

    Also, I have a 6 foot butterfly castle in which the cats hung their crysalis. Some of the butterflies appeared to have fallen while drying their wings. Could the 6 ft drop (to carpeted flooring) have stunned them so they couldn’t climb back up to finish drying? …. like the one I found “stuck” between the net and paper towel…. or the one that was just dead on the floor for no apparent reason. I noticed that you have crysalis hanging from your ceiling. Do the butterflies ever fall and hurt themselves at your place?

    1. Hi Bett, sorry to hear you are experiencing problems with your butterflies. It sounds like you could be experiencing a problem with OE infection which can cause weakness and deformities in butterflies. Butterflies don’t typically fall from chrysalides unless there is inclement weather(high winds/heavy rain), disease, or overcrowding (touching each other).

      I rehang our chrysalides from the ceiling, but if you aren’t around to see monarchs hatch in the morning hours I recommend letting them hatch in your mesh cage. In the past two years, I have had one butterfly fall from the ceiling, but found it soon after falling, so he was able to dry and fly.

      If butterflies have been affected by pesticides they typically die within days and you’ll find green fluid (vomit) inside the cage.

      If you haven’t had a chance to go over my guide, it outlines the process I use to raise monarchs with a 95% survival rate. Good luck with your raising!

      Raising Monarchs Guide

  160. We have milkweed in our backyard, not sure of the species. Anyhow, my youngest daughter found eggs and even a TEENY caterpillar, still not sure how she had seen that! We brought out her old butterfly collapsible, mesh cage and placed a newly purchased milkweed potted plant inside. I relocated the caterpillar to that plant and place it in the mesh cage at the request of my animal lovin’ daughter. She was afraid the lizards would eat him if we left him on the plants that are growing in our garden. He seems to be quite healthy and so does the plant. I may have to trim the plant so it doesn’t push the mesh lid open. Do we still need to mist the plant if we are watering the plant? Also, do we need to prepare the mesh cage so that he will have a place to attach his chrysalis? Or will he attach to the cage or the plant. Thanks for your help. I am loving the information you provide to help young animal lovers as my daughter feel like they are helping out with conservation of our animals and insects!

    1. Hi Stacy, you do not have to mist if you are watering. What can potentially the caterpillar is not having hydrated milkweed. Your daughter is very smart to bring in the caterpillar, since some lizards do eat monarchs…the survival rate outdoors is estimated to be less than 5% and I always feel bad when people tell me all their caterpillars have “disappeared”. Good luck on your raising journey!

  161. I understand your feeling of horror when you discover that the monarchs your are lovingly raising are destroyed by a fly parasitoid. But the situation is far more complicated than it appears at first sight.

    It is important to know that most Tachinids are invaluable biological controls, attacking a number of insect larvae that destroy crops or garden plants. There is even one that feeds on Japanese beetles. The page you link to provides false information. For instance it shows a picture of Archytas, a species of tachinid that doesn’t even care about monarchs. Its favorite hosts are earcorn caterpillars, tent caterpillars and a few other undesirable ones. The species that feeds on monarchs, Lespesia archippivora, also attacks a number of pests. It is even used as a biological control. Killing the ones parasitizing your monarch caterpillars will not make any difference on their populations because most of them are feeding on other species.

    All and all, Tachinids help cut down on pesticides because they are such good pest controls. So, indirectly they help monarchs more than harm them. It is also good to remember that monarchs and Tachinids have coexisted for many thousands (millions?) of years without going extinct. It is us and the things we do that pose the biggest threat to this and many other species.

  162. Hi Rebeca, you can switch monarchs to other milkweed species pretty easily. They may protest a bit if you switch TO Asclepias tuberosa, but they will eat when they get hungry.

  163. I have a question concerning caterpillars and their milkweed. If my caterpillar is chomping on the giant MW and I run out, can i give them the tropical or other variety of MW or would the different toxins kill them?

  164. i raise lots of butterflies not many monarchs yet just got milkweed they love the yellow flowerd milkweed . i have 2 nice monach butterflies they are both healthy males . one i taged and i am gonna release him soon . but the other i trained to do cool thing sadly he has a wing that is kinda short and bent i am not sure how to fix it has good wings just the rong way shoud i cut off the wing and place it in the right spot or glue it back in place . i have no dead monarch butterfly wings . he eats all the time it loves shuger water . i was not planing to let it go cause it will not make it to mexico . i live in florida so it might not need to leave any way . i don’t want it to try if it is weak but the other i hope it trys . i know its part of life to diy but it can’t hurt to try helping it right . they only live 2 weeks to 6 months . i want to find a female for my males .

  165. Hi my wife and I are new to raising monarchs. Did a few successfully than the last two batches the either died in the cacoon stage or when they emerged their wings where damaged, different size and they could not fly. Also we saw twice that a monarch picked up n other monarch and flew away with it

    1. Hi Hans,

      welcome to the world of raising butterflies. It’s an awe-inspiring and amazing experience for sure. You will find more consistent success once you have a good raising system in place. If you’re interested in learning about the system I use to raise monarchs with a 95% survival rate, check out my raising guide:

      Raise MORE Monarchs with LESS Effort

      As for one monarch carrying off another…that’s how they mate! The males carry off the females to a more intimate location (i.e. tree tops). Here’s a photo I took a couple season’s back:

      Monarchs Mating on Mexican Sunflower

  166. Tony, I just wanted to drop you a note to tell you our last two Monarch caterpillars moved to chrysalis and then a few days ago the first came out a perfect gorgeous huge Monarch butterfly. We watched her fly away and now she comes back regularly to feed on our flowers. Then yesterday our second Monarch butterfly left his cocoon – also a gorgeous perfect Monarch (smaller than the other) and flew away a few hours later. I am so relieved and happy that our last two were complete successes. I was dreading having to euthanize another deformed, wingless or legless Monarch. So next year I will wash the milk weed and cut it back in the spring and hopefully we’ll have all successes. Thanks again for your help. Happy Holidays. Cynthia

  167. So glad to find this site! I raise monarchs in Hawaii, where we don’t have weather colder than 65-70 degrees. They only eat crown flower leaves, as we don’t really have milkweed here. I raise them indoors because here the black ants eat the hatchlings and the birds eat the caterpillars. I have to put the cage in the muddle of a water “moat” or the ants will attack them. It’s worked fine in the past and I’ve raised hundreds over the years. But lately more and more of my butterflies emerge from their chrysalis unable to hang on to their casings , fall and form crumpled wings. I clean the cage and replenish with only the tenderest leaves from my tree everyday. Maybe I am handling them too much, as I try to get them onto fresher leaves to keep them hydrated. I don’t know if we have the same diseases you do on the mainland. We seem to have fewer and fewer butterflies .

    1. Aloha Phyllis!

      sorry to hear you are having some issues raising monarchs. It sounds like this is a disease problem and not anything to do with handling. As long as you handle caterpillars with care, this isn’t the cause of sickness or death. If your milkweed is in constant use, it would probably be a good idea to cut it back at some point so healthy, fresh growth can emerge. Sometimes a “break” from raising is a good idea. Please keep us posted!

  168. From Zone 6 in SW Indiana: What causes death in the chrysalis stage? Our garden is hydrated so I will guess it is not dehydration. This is a school butterfly garden and the caterpillars all climbed up the 12 foot wall to move on to the chrysalis stage under the eaves of the building. Some also just clung directly to the brick wall. Do they need a better place to go for their transformation? (tree/bush/perch) I counted at least a dozen chrysalises that never made it past that stage. Too late for this season but I want to make improvements for next year! Thanks.

    1. hi Nancy, it could be tachinid flies, wasps, bacterial disease or virus. Only 1-5% of monarch butterflies survive outdoors and most won’t even make it to the chrysalis stage. This page has helpful resources if you would like to start raising monarchs next season:

      Raising Monarchs Resources

  169. Thanks, Tony. I’m down to two chrysalises and one should open today. They are very small so I suspect these will be born without wings too. Terrible to watch. I’ll check out your guide and keep reading before next season to try to avoid a repeat of this season. My family & stepchildren (they’re French so they are coming a long way) are arriving on Monday for 21 days so that will be my focus until December but then I’ll have time to give this to again. Thanks for all your help.

    One last question. I see a lot of ‘wash your milk weed leaves’ comments around the internet. How do you wash milk weed leaves? Just with water or some other product. Since they eat the leaves, I know it can’t be anything that could harm them.

    Thanks. Happy Halloween and Thanksgiving. Cynthia

    1. Hi Cynthia, some raisers rinse the leaves with a 5-10% bleach solution before rinsing again with water (at least I hope they do!). I only rinse milkweed leaves with water. Happy holidays and enjoy your family time!

  170. We have milkweed plants and the wasps were getting all our Monarch cats so I brought the surviving ones into our porch and put them on milk weed plants I bought at a nursery. They all went into chrysalis on another plant that they seemed to like a lot (I never sprayed the second plant but I’m not sure if the nursery sprayed the milk weed – I didn’t think to ask). Today they are starting to come out of their cocoons and they immediately drop into the dirt below rather than holding onto the cocoon to dry their wings and get strong. It looks like their legs are curled up and can’t extend so they can’t hold onto anything. On the ground their wings don’t spread out and get fluid in them and get all crumpled.

    We tried extending their legs and spreading the wings but nothing worked. After several hours we had to kill them both because it was clear they’d never fly and they seemed to be suffering. What went wrong? We don’t know what to do since we have four more in chrysalis and don’t want to lose them. Is it too late to do anything to help them? I’m so sad to be losing such gorgeous and endangered creatures after weeks of mothering them and trying to create a safe environment.

    A side note – I called the nursery where I bought the milk weed and they said that they do NOT spray their milkweed with pesticides or other chemicals. Cynthia

    1. Hi Cynthia, unless the caterpillars are parasitized by tachinid flies, it’s hard to know (conclusively) what happened. If the nursery buys plants from a grower, then they can’t be sure whether the plants were sprayed or not.

      If they can’t hold onto the chrysalis, it sounds like they are weak. Perhaps OE infection? If it’s either of those issues, your other monarchs could have issues too. All you can do at this point is monitor them.

      I’m not sure where you’re located but “fall planting” now is a good way to increase your milkweed supply for next season…good luck!

      Fall Planting Milkweed

      1. Hi, Tony, thanks for your reply (which I just saw). I’ve been taking the chrysalis inside my house at night now to keep them away from the cold. We had another one come out once we took her outside this morning but I knew from looking at the chrysalis that there would be problems – just too small. It came out with virtually no wings – tiny stubs. We only have two left but I’m not hopeful for them either. Very discouraging and disheartening.

        We’re in SW Florida and I have 8 Milk Weed plants now but I’m having no success and am starting to wonder if they’d have better luck outside with the wasps than with me. Are there any plants that are toxic to Monarchs? Perhaps the plant that I’m putting next to them to crawl on and make their chrysalis is a problem? I’m not seeing signs of parasites or bacteria but I’m NOT an expert – this is my first attempt of helping Monarchs and I’m learning as I go.

        Thanks again, Cynthia

        1. Hi Cynthia, it’s really never “too cold” for the monarchs to be outside in South Florida, and there is a year-round population there. If there have been a lot of monarchs on your milkweed over the season, I would suggest cutting back your plants to 6″ in case OE is the issue. This will allow fresh, healthy growth to emerge from your plants. When disease is an issue in warm regions, sometimes it’s best to take a break and give your milkweed a fresh start. good luck!

          1. Hi, Tony, I read on another site that a guy who raises 200 Monarchs a year found that cold (less than 68 degrees consistently for a full day) created ‘deformed legs’. I was desperate so I thought I’d try to just bring them in at night since temps were dropping below 60 at night.

            I did cut back my ‘in the ground’ Milk Weed once I took off the caterpillars and will cut down the others that I bought soon. We seem to only see the caterpillars and Monarchs once (maybe twice?) a year here so it made me think they were seasonal. Anyway, I’ll use fresh Milk Weed in the future and hope for the best. We never use pesticide on our plants so they will for sure have clean Milk Weed. I’ll keep trying to educate myself in the meantime. Thanks for your help. Cynthia

          2. Cynthia, I’m not sure how this person was able to conclude cold caused deformed legs? I recently brought in 2 caterpillars that had been outdoors when the temperature dipped to 37 degrees and they eclosed in perfect health, legs and all…and I saw an adult monarch in our garden the day after the temp got down to freezing.

            Anyhow, we raise ours in a 3-season porch, but when it gets into the low 50’s overnight I bring them indoors to keep them active and eating. Sorry things have been disappointing this season. Once you get a good raising system in place, things should go a lot smoother for you. If you want to follow the system I use to raise monarchs with a 95% survival rate, check out my raising guide…good luck!

            Raise More Monarchs, with Less Effort

        2. If you are in SW Florida, on Facebook, you can go to “Southwest Florida Monarch Monitoring Project” and get more information. Good luck!

  171. We have a late season monarch who has had great difficulty flying from the start and will only seem to eat when we feed her honey water on our fingers. Her wings are very brittle and are literally falling apart. We are committed to keeping her and feeding her until she dies, and will be sure to disinfect everything in case this is OE. I have not been able to find information about monarchs who have wings falling apart, though and would appreciate any information about this.

    1. Hi Andrea, I’ve never heard of this happening before, but it sounds like you are doing the best you until she flies off to the big milkweed patch in the sky. Thank you for taking care of her!

    2. Andrea,

      I’m in Southern California and experiencing the same thing. I’ve had two Mamas desperately lay the remainder of their eggs on my garden as their frail wings seemed to fall apart with each flutter. I’ve rinsed the plants and over 100 eggs hatched. I’ve caged the ones I could find, at least 92, (I keep track with a tick mark on paper with each caterpillar added.)

      The eggs started hatching on Monday, October 13, 2014 and are continuing to hatch as of today, (I found an additional 37 this morning and check multiple times daily.) I’m not sure if I’m doing them any good, but in have hope they will thrive and help with the migration. So far all seems good, but only time will tell.

      1. Oh! And thank you to this site, I am new to milkweed and monarch tending, my Grandmother did this when she was alive and I’ve picked up her torch now that she’s her own butterfly in the sky. I just learned how I could keep the caterpillars safe from the get go and store the eggs. Thank you! I’ve lost many babes due to not harvesting the eggs and spent countless hours searching for microscopic dropping and tiny holes in leaves to find them once they’ve hatched. Thank you for the information and education.

  172. Hi Tony,

    One of my monarch pupa was trying to come out today but somehow the chrysalis did
    not open enough and the butterfly did not com e out… it is now very black and now
    moving at all.. I plan to keep it until morning and if nothing happens to declare it dead.
    Any ideas as to what could have happened?
    Thanks, mj

    1. Hi Mary, so sorry to hear this. My guess would be OE infection or dehydration. These issues can typically be prevented if you have a good raising process in place. You might find my raising guide helpful for raising future monarchs…good luck Mary!

      Monarch Raising Guide

  173. I have collected 7 caterpillars a few days ago. 2 went into a J form. Now they look deflated. One of them has a white string hanging down from it. Are they dead?

    1. Hi Christa, sorry to hear this. It sounds like they were parasitized by tachinid flies…you should see maggots or red pupae on the cage floor. Just discard them. I hope your other chrysalides are OK! (monarchs get this parasite when an adult fly lays eggs on the caterpillar)

        1. By bringing in eggs or tiny instar 1 and 2 caterpillars…sometimes they will still get the small caterpillars though. Unfortunately, it’s hard to tell if the caterpillar has parasites by looking at it. I still bring in caterpillars, since the majority (in my experience) are not infected.

  174. We had a caterpillar that was in a “J” formation and had liquid dripping from it. It made the Chrysalis. Now the Chrysalis has a dark brown blotch on one side. We are thinking it is dead. Could this have been caused from stress? We transported it while in “J” formation b/c it was the day we were to show it to a class. I have never seen one squeeze out liquid before.

    1. Hi Michelle, sorry to hear this! I’m not sure what kind of “stress” the caterpillar went through on it’s trip so it’s hard to say if that had a negative impact. There are viruses and parasites that can also affect monarch caterpillars. The easiest one to diagnose is the tachinid fly because maggots and pupae will drop from the chrysalis on to the cage floor. I would still keep the chrysalis to see what happens. good luck!

  175. I have half a dozen chrysalises and am just now reading that they should be spritzed daily. Is it too late??

    1. Hi Carol, If your milkweed wasn’t rinsed/sprayed so that the caterpillars were sufficiently hydrated, I would consider spritzing them daily. Otherwise I don’t spritz monarch chrysalises and have never had an issue with butterflies eclosing.

  176. Hi Karen,

    freezing is a method recommended by many. I hear it from reliable sources that it doesn’t hurt the butterfly, but I often wonder how anyone knows for sure. Personally, I put them in paper towels and squeeze. To me, that seems more humane but I understand that many people can’t do that. Either way is a much better option than leaving them to infect other monarchs. It’s your call…

    1. Thanks for responding. No, of course. I separate any butterfly that doesn’t form normally from other butterflies. It’s still sad to see it struggle and not be able to survive on its own so I do feed it. Amazingly, over the years, I have seen some last this way for several weeks. It is difficult for me to freeze it or squish it although that would probably be the quicker and less painful way to go.

      1. Yes we ran into one in the wild that I think had OE; wings looks darker and one was missing it’s tip and it was acting all crazy–it literally attacked the two males we had just released. Which is just great as that is a good way to spread it, I figure. Were able to separate them but I ended up releasing it which I now regret but it all happened so fast and I didn’t really think enough. It would have been hard to kill but is probably what I should have done. It left another female there totally alone. I have little experience yet but that was bizarre and of all the dangers I knew they faced out there I did not think fellow Monarchs could be one of them.

      2. I put the sick one in thick paper towels and step on it hard. I feel it’s quick and fast. I’ve had to do it three times, I cried the first time.

  177. Hi Tony,
    Enjoy your site and have learned a lot about monarchs. One thing that I haven’t seen addressed is how to humanely dispose of a live monrach if it fell from its chyrsalis and its wings improperly formed or if butterfly is sickly due to OE. I’ve read where you can put the sick butterfly in an envelope and put in the freezer. I’ve been reluctant to do this as I can’t believe that it’s not painful for the butterfly to freeze to death. Your comments?

  178. I have a question about the OE.
    The article said destroy any Monarchs with the spores after taping. It says that the spores will remain on the plant and infect a caterpillar up to 2 years later.
    QUESTION:
    What can be done to get rid of the spores on the plants?
    Is it worth it to try and get rid of all the spores only to have a Monarch to fly in that’s infected?
    If I were to grow indoors it would be.
    I was growing new plants indoors to keep the Butterfly s from laying the eggs and eating the crop.

    1. Hi Kimberly, the goal isn’t necessarily to remove every last OE spore, but to greatly reduce the levels so they’re not so detrimental to monarch health. You can cut down levels by cutting back plants to about 6″ so healthy stems and foliage can emerge. This is recommended for those in regions where tropical milkweed grows year round and is reused by monarchs. Otherwise, rinse off milkweed cuttings and individual leaves with water before serving them to caterpillars.

      Rinsing milkweed, regular cage cleaning, and not letting butterflies hatch over caterpillars are your best defenses.

    1. I have found that since I quit picking up the caterpillars by hand & moving them around, I have had much less disease problems. I remove poop several times a day to help keep the cage clean. I put a newspaper in the bottom of my mesh cage to catch the poop & I also use a hand-held vacuum to pick up some that I might spill when changing the paper. I also mist the leaves each time I change them. I do have a question about the chrysalis….should I remove the empty ones each time a butterfly is hatched? I have quite a few on the ceiling of my cage right now. Also, I have 3 that made their chrysalis under a leaf & 1 that laid on top of a leaf & I watched it pupate into a chrysalis while laying there. He was attached to the leaf. I cut off pieces of the leaves with the chrysalis on them & taped them to the side of the cage as the tape didn’t seem to stay on the ceiling. I don’t want to hang them out in the open inside my house. I have a cathedral ceiling & I’m afraid I wouldn’t be able to catch them to release them outside.

      1. Hi Judy,

        unless you’re raising a mass of monarchs, cleaning out frass twice a day should be enough. As long as your “leaf” caterpillar is able to hang straight down it should be fine. For future reference, if tape doesn’t work you could also try pinning the leaf to the cage ceiling.

        Handling caterpillars does not hurt them unless you are pulling them too hard when removing them. Several gentle pulls are much easier on the caterpillar than one hard pull. Caterpillars don’t get diseases from people.

        Yes, probably not a great idea to have a monarch loose with a cathedral ceiling! 🙂

  180. I read somewhere to keep everything dry dry dry. I’ve been raising the cats in my garage since we’ve had a lot of rain this summer. I’ve only lost two cats. I think the article said cats die from pseudomonas, which is found in stagnant water. Do you know anything about this? Is this true?

    1. yes, caterpillars can get diseases from overly wet cage conditions. The mistake some people make is taking this potential issue to the extreme and not hydrating the milkweed. Caterpillars need water for healthy development, but standing water in a cage is the catalyst to disease. Mesh cages have good air circulation so using small amounts of water to spritz caterpillars/milkweed should not be a problem as long as you clean up frass before spritzing.

  181. I have a mesh cage. How do you clean it once a chrysalis is formed?
    Mary

    1. Re: cleaning mesh cages. Shake it out to remove debris, and peel off any silk, etc., you can see or feel. Flatten the cage, and pop it in the washing machine with towels, add a Tbsp of bleach with your soap, and skip the fabric softener. Run through gentle or regular cycle, warm, hot water is OK.

      At the end of the wash cycle, open the clean cages and let them air dry. I like to set mine out in the sun.

  182. I purchased my first monarch caterpillar at the state fair.
    On the third day he went into making the silk, then hanging he had one third of his skin down with the new skin totally sunken in together. He never made it pass that.

    The next morning he was lying on the floor, in the same condition as when he was hanging up.
    This is my first time, and I have cried and been sad.
    What do you think caused his death?

    1. Oh Catherine, so sorry to hear this. I know many times the caterpillars you get at state fairs may not be very well taken care of and in overcrowded conditions. They also tell you they don’t need any more milkweed to feed on, which is not always true. My guess is there was already a problem when you got the caterpillar. I am sorry your first time ended like this, but I promise it gets better if you keep trying and follow a good raising process.

      1. Hmm I guess I generally support anything that help this species and/or awareness of it but yeah “cats from the state fair” sounds a little shady and I feel bad for the little guys.

      2. My butterfly just came out of his cocoon. His wings are not fully extended and seem to stick to parts of his body. What can I do???? Help!!!!

        1. Hi Maureen. If the butterfly emerged like that and was weak, it’s most likely due to sever OE infection. The best thing to do in that case is to euthanize to prevent spreading the disease. Sorry this happened…

    2. Why is my one monarch caterpillar a little different color… it’s a little more black it seems healthy it will take leaves from my hand not like the others I never touched it before. Will it get black death like?

      1. Hi Hadre, sometimes monarchs have thicker black stripes. Some believe it has to do with temperatures and exposure to sun, while some scientists believe it an immune system response. I have successfully raised caterpillars with thick black stripes and never had any apparent health issues. I would monitor the caterpillar and isolate him in another cage if you have one. Good luck!

        1. thanks . ya it is yellow and black it happend last time he shed his skin . he is heathy . i keep them all alone to make sure after my 2 caterpillers got black death . they shoud be good . only one died with my 4 now .

    3. Hi,
      I planted milkweed (northern type) in my garden near Charlotte NC and planted zinnias around it to attract Monarchs. I was thrilled when I saw a Monarch on the zinnias, then laying eggs on the milkweed leaves. I checked with pictures on the internet, and it definitely was. Then about 6 days later, I was thrilled to see baby monarch caterpillars on the milkweed and holes in the leaves. I could see their stripes clearly through a magnifying glass and counted at least ten of them. Now a week later, I can only see one monarch caterpillar. I’ve never sprayed the garden with anything, and it’s way up in the back away from the neighbors. We have a lot of insects here, and it’s been in the 90’s for a couple of days. Any idea why my caterpillars would disappear?
      Martha McKiever – Indian Trail, NC

      1. Hi Martha, unfortunately, most monarchs fall victim to predators like wasps, spiders, ants, stink bugs, etc…garden life is tough!

      2. lots and lots of caterpillars are eaten. we have a lot of wrens at our house and we are suspect of them wiping out all our black swallowtail caterpillars! 🙁 we only plant parsley in the garden to attract black swallowtails and were heart broken. 🙁

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