Stop Milkweed Pests from Ruining Milkweed for Monarchs
You might be familiar with the butterfly gardener catchphrase plant it and they will come. The it I am referring to is, of course, milkweed…the lifeblood of monarchs!
Milkweed comes in many sizes, flower colors, and growth habits for North American Gardens.
The good news is that monarchs will utilize many different species of milkweed to support their life cycle.
The bad news is magnificent milkweed also attracts a variety of unwanted pests.
These pests can damage the milkweed so it’s less appealing (or unusable!) for the monarchs you are trying to attract and support.
In the long term, the best way to conquer milkweed pests is by diversifying your milkweed and by planting several patches around your yard and garden.
In the short term, a limited supply of milkweed might call for more drastic measures to take back your patch!
This is a (growing) list of all the usual suspects, and what you can do to save your milkweed for the monarchs:
Japanese Beetles
- Popilla japonica
- Common Milkweed pest and butterfly garden ornamentals including zinnias, butterfly bush
- Devastating damage to many tree/plant leaves and flowers included in urban landscapes
- Stop them from taking over milkweed by dropping them into a bucket of soapy water
- Pheromone traps work well, but keep them away from your garden to avoid attracting even more of these uninvited pests.
- Treat the feeding grubs in late summer/early fall by spreading the natural-occurring bacterium milky spore across yard and garden with a broadcast spreader
Beetles Be Gone! This tip was given to me by Lloyd Brace, who ran a rose nursery in Maine: “For bad Japanese beetle infestations, put a an inch or two of water in the bottom of a wet/dry shop vac. Add a little Dawn dish soap and stir. Go out in the garden and suck those suckers up. WARNING: It’s addictive. Once you’ve cleaned up your yard, you’ll want to go vacuum at the neighbor’s.” Go Lloyd!
Milkweed Beetles
- Tetraopes tetrophthalamus
- Often found on common milkweed
- Larva (grubs) burrow beneath the soil to feast on milkweed roots, which explains why you don’t see them crawling around your patch. They can also access the root by tunneling through the stem.
- These herbivores feast only on milkweed and won’t harm your caterpillars
- Squeaking? It’s been reported that milkweed beetles squeak excitedly when eating milkweed. if you’ve heard this squeaking please comment below…
- Leave them if you have enough milkweed to sustain them. They are harmless and part of you local ecosystem. If predators can’t find them, who’s left on your milkweed?!
- Stop them from taking over milkweed by squishing or dropping them into a bucket of soapy water
We never see large numbers of milkweed beetles in our northern garden…more proof that predators are adapting to the toxic cardenolides in milkweed.
Milkweed Bugs
- Oncopeltus fasciatus
- Female milkweed bugs can lay up to 2k eggs in one month
- Nymphs are mainly red with black markings
- Adults have full-grown wings
- Damage milkweed by eating milkweed seeds and tissue from the plants
- Protect your pods/seeds by tying mesh organza bags over them
- Stop them from taking over milkweed by dropping them into a bucket of soapy water
- Insecticidal soap is an option for heavy infestations- rinse plants thoroughly after use to protect future monarchs!
- They are omnivorous, focused mainly on milkweed, but will also eat eggs and small caterpillars
- Leave them if you have enough milkweed to sustain them. They are harmless and part of a healthy local ecosystem
Keep in mind, any substance left on milkweed to repel pests will also prevent monarchs from using those plants.
Milkweed Leaf Miners
- Liriomyza asclepiadis is the specific species of leaf miner that feeds on milkweed
- Small fly larvae that feed on milkweed in between leaf layers, making them unsuitable to nourish monarch caterpillars
- The only way to get rid of miners is by removing/discarding the affected leaves
- Systemic pesticides are used for large infestations, but this is not an option if you want to support monarchs
We recently had some leaf miner damage on our poke milkweed, and removing the leaves was effective in stopping their spread.
Milkweed Weevils
- Rhyssomatus lineaticollis is the specific species of milkweed weevil that feeds on common milkweed causing leaf damage and distortion
- R. lineaticollis feed on young common leaves before working their way to the stems to lay the foundation for the next generation
- Rhyssomatus annectans is the specific species of weevil that feeds on swamp milkweed
- R. annectans seem more stem-focused for feeding and egg laying. The less substantial swamp stems start to droop before breaking. These swamp milkweed buds will never bloom to support monarchs and other pollinators
- Since these nocturnal pests are milkweed species specific, some have suggested crop rotation. However, since these are perennials, that doesn’t seem feasible
- IF weevil damage is a serious issue in your region and you want to prevent this from occurring, get out that soapy bucket of water in spring (hopefully before weevil eggs are deposited) and start flicking them in. Otherwise, weev them be
In our northern region we haven’t found weevils to be a serious issue on common milkweed, but they are wiping out too many stalks of swamp milkweed. Next spring, they will be dealt with…
Oleander Aphids
Oleander aphids (Aphis nerii) are probably the grand daddy milkweed pest of them all. While many of the pests on this page are regional, aphids have become equal opportunists across North American butterfly gardens.
In fact, as a special pest of honor, they even have their own page:
10 Ways to Stop Aphids from Taking Over your Milkweed Patch
Snails and Slugs
In our northern garden, these are not an issue, but some gardeners in warmer regions rank these as their worst milkweed pests. They sneak in at night and leave you with a sorry milkweed patch surprise the next morning.
After researching the topic, I came across a few different solutions including epsom salt (hydrated magnesium sulfate) which is also beneficial to plants. If you use epsom salt, keep in mind this has the same potential issue for caterpillars as spreading diatomaceous earth…when the caterpillars crawl off the milkweed, sharp crystals can cut them open and kill them.
If you water the epsom salt areas thoroughly before caterpillars cross the soil to pupate, this can be an effective solution:
Regular snail baits are toxic to other animals and wildlife including your pets, so I would think twice before using them…
With Sluggo Organic Snail Baits, the iron phosphate and bait combination immediately stops slugs and snails from feeding after the bait is eaten. The pests will die within a few days…
Sluggo is non-toxic to pets and other wildlife:
Buy Sluggo Organic Snail Baits here
Spider Mites
What can you do, when you first start noticing spider mites on your milkweed?
- Tetranychus urticae
- Hope their natural predators (including lacewing larvae) will take care of them for you
- Cut back affected areas and discard…don’t compost!
- Rinse spider mites away with water. I’ve heard from many gardeners this isn’t very effective
- Isopropyl alcohol will kill them on contact. Apply with a spray bottle or cotton swab.
- Insecticidal soap works too. You can even make your own at home
If your plant looks like the video above, it’s time to cut your losses and hope for a fresh start next season. Early intervention is the key…
Swamp Milkweed Leaf Beetle
- Labidomera clivicollis
- These have become a major issue in warmer regions decimating milkweed patches, and stopping them from flowering/seeding
- Don’t be fooled by their common name…they’ll eat many types of milkweed
- in northern regions they are less of an issue because they show up later in the growing season so there’s only one generation
- Reduce their numbers by flicking them into a bucket of soapy water OR
- Remove eggs you find on milkweed or nearby plants, but don’t confuse them with beneficial ladybug eggs
In our northern garden, we only remove Labidomera eggs, but don’t go out of our way to look for them. They have not proven to be a serious pest…yet.
Thrips
- Thysanoptera order
- Nicknamed freckle bugs because of the white-freckled damage that occurs on the plants.
- Long, slender insects with fringed wings
- Adult thrips are about 1mm (.04 inches) long
- Over 6k recorded thrip species that suck the life from plants around the world, including your precious milkweed ?
- Thrip damage ruins leaves, milkweed flowers, and negatively impacts seed viability.
- Look for leaf streaks, speckled leaves, and small white patches. See actual thrip damage here
- Ladybugs and lacewings are natural thrip predators
- Spray affected areas of plant with water to get them off OR
- Cut off affected areas of plant and discard OR
- Use insecticidal soap (rinse plants thoroughly after use). You can even make your own at home
- Do not use neem oil or other systemic pesticides that will kill caterpillars.
Tussock Moth Caterpillars
- Euchaetes egle
- Often found on common milkweed, but they feed on most varieties
- Nicknamed the tiger milkweed moth for its orange, black, and white hair tufts
- While they can decimate milkweed, their numbers are kept down by predators.
- Adult moth has gray wings and a yellow abdomen with black spots
- Leave them if you have enough milkweed to sustain them. They are harmless and part of you local ecosystem. If predators can’t find them, who’s left on your milkweed?!
- Stop them from taking over monarch-reserved milkweed by relocating eggs/small caterpillars to older milkweed plants. Dogbane is an alternative tussock host.
Whiteflies
- Trialeurodes vaporariorum
- Whitefly is a common pest in western states
- Hurts milkweed by sucking sap from leaves
- Stop them by spraying leaves with water or using an insecticidal soap
- Spray isopropyl alcohol on eggs and/or flies…this has worked well on our overwintering plants
- Blow on them and they’ll fly away…but will likely return when the coast is clear
- Vacuum them up with a micro vacuum attachment or a mini keyboard vacuum cleaner
Question to Consider: if a milkweed pest isn’t causing serious damage in your region and your milkweed patch, it is really a pest?
My milkweed plants are being ravaged by beetles and aphids. The leaves are looking almost like there is some kind of fungus going on – or just stressed by the pests. I have fennel in the same area which is not doing well either, but can’t see any pests on them. Any suggestions?
hi Susan, read the post for suggestions on dealing with insects….for plant fungus, check out this post:
Milkweed Diseases and Fungus
Thanks for your great resources! We have had problems with our swamp milkweeds for 3 years now. The damage is consistent with weevils. All of our swamp milkweeds have been completely destroyed in two separate locations. It seems the weevils have moved on to tuberosa as well (I found an article from a university extension office saying weevils have that eat incarnata can eat tuberosa also). I have not had luck finding weevils but I haven’t really gone looking at night. Can I spray neem oil in the soil in the fall to destroy weevil eggs?
Hi Seth, unfortunately, neem oil is an insect growth regulator and will kill caterpillars. Other than flicking them into a bucket of soapy water, no good solutions here besides spreading out patches and planting several varieties of milkweed…good luck!
I used to have a lot of caterpillars but now the small and larger black ants have taken over all my milkweeds in different parts of the yard. Any way to get rid of them? I haven’t seen a caterpillar on any plant yet this year. They would not stand a chance if they did hatch out.
Hi Jack, ants are tough…there’s so many. We try to plant several milkweed species and spread out patches for this reason, but it’s still difficult for caterpillars to go undetected. Check out more info on predators page: Ants
Great information but a serious alert about organic solutions. For instance, Neem Oil is organic, but it is still designed to kill and will kill your caterplillars. Organic only means it is not made from chemicals. Neem Oil is made from chrysanthemums for an example. There is really nothing you can spray or apply that will kill other insects and not butterflies or caterpillars.
Please get this information out there!
Hi Julie, we have a warning about neem oil here:
12 Monarch Diseases and Caterpillar Killers
Julie, Neem Oil is actually from the Neem Tree. There IS an actual Neem tree! It is an awesome tree. It is also true that there are pesticides made from chrysanthemums, and marigolds, too. The pyrethrin compound is extracted from the plants, or sometimes a synthetically produced pyrethrin is used. I just think neem trees are cool and want to give them their due credit! (The compound extracted from neem oil is called Azedirachtin, also a pest deterrent.)
Hi Tony,
I live the San Francisco Bay Area and have been raising Milkweed for Monarchs for 3 years now. This year I having a “Milkweed Massacre”, most of my Tropical Milkweed (cut back each year) and some of my native Narrowleaf Milkweed are nothing more than stalks, they have been denuded of leaves and the flower head sheared off. When this first started I thought I must have a load of Cats. However, I can’t find any and they would have to be BIG to eat this much! I set up an album of pictures at
https://photos.app.goo.gl/3xiV9JFiksojfRUH8 to show you.
Do you have any idea on what is doing this?
–Del
Hi Del, sorry to see your milkweed is getting munched down…maybe mice/rats or squirrels? definitely something bigger than a caterpillar if this happened overnight…
Groundhogs
Ground hogs and rabbits are my biggest problem. I’ve seen a rabbit completely devour a foot tall common milkweed in a few minutes. It’s actually amazing.
Hi Del, perhaps you could install a motion camera and see if you can see the culprit in action…good luck!
I have a leaf miner infestation AND monarch eggs and cats! I can remove leaves, but will be removing eggs, sadly. Do leaf miners spread disease?
Thank you!
Hi Caitlin, not that I know of. I would remove the affected leaves. If they have eggs, you could cut off a small leaf piece with an egg and put it in a sealed food container. More info here:
Gathering and Protecting Monarch Eggs
I had weevils last year and weevils again this year. I have been taking them off and squishing them but i noticed the stem of my milkweed has like rips in it. Is that the weevil doing that or just the way the milkweed is growing? I also had aphids last year… and ants…i tore everything out last fall and put new seeds this year. Although i know some of the MW coming up is from last year. Only my 3rd year in this garden bee balm, black eyed susan, pye eyed joe, mums and a few other things. And lastly, i am in Elk River just nw of you. 🙂
When I see ants, I think of aphids nearby.
I had weevils last year and weevils again this year. I have been taking them off and squishing them but i noticed the stem of my milkweed has like rips in it. Is that the weevil doing that or just the way the milkweed is growing? I also had aphids last year… and ants…i tore everything out last fall and put new seeds this year. Although i know some of the MW coming up is from last year. Only my 3rd year in this garden bee balm, black eyed susan, pye eyed joe, mums and a few other things. And lastly, i am in Elk River just nw of you. 🙂
Hi Laurie, we have weevils too that eat some of the common milkweed, but they’re not super destructive like the swamp milkweed leaf beetles have become so we let them stay in the patch…good luck with your garden!
Hi Tony,
Tried to reply but for some reason it isn’t working on my end. Thank you for the info- I have common milkweed here and inspect them every day, haven’t seen any evidence of invaders but will just cut this one back to be safe. Thanks again!
Hello,
It looks like something has bored into one of my milkweed stems, not sure what it could be after researching. Do you recommend just removing it to prevent further damage, and any ideas as to what this could be? Thank you 🙂
Hi Jen, swamp milkweed leaf beetles and milkweed weevils sounds like possible suspects. This happened to a bunch of our swamp milkweed last year…we cut back affected stems. This spring we are removing swamp milkweed leaf beetles preventatively, hoping to prevent a repeat of last year.
We have had our milkweeds surrounded by flies…it was a real upsetting to see this, and last year we had what seemed like thousands of the milkweed assassin bugs…I tried to get them off with duck tape..as to not spray chemicals to harm any potential monarch eggs/caterpillars or butterflies…this is hard work! So far 3 years and not one caterpillar found but a new set of other bugs stopping by..
Hi Gabby, I would try planting several milkweed species and spread them around a bit. If it’s one big patch that’s been found by predators, it can be difficult…
Hi Tony, Have you ever head of milkweed disappearing? My milkweed garden that I had for over 14 years started disappearing 3 years ago. I had hundreds of plants all over my front and back yard. I have replanted and reseeded and nothing comes up. This year only 5 plants showed up, are growing very slow and one died already. I can not figure it out. I know about the diseases and milkweed predators and have been taking care of them by digging up the diseased plants and hand picking the predators. I can grow swamp milkweed and tropical milkweed but there is so little food on them. Any ideas? I don’t know what to do. Please email me if you know anything about this situation.
For now, I have brought them inside, I am in a townhome so not much in the way of animals, I thought, they eat nothing else, picky eaters I guess and no trace of what they bite off, which would be a good 12″. Going to try to put them in the butterfly house to raise until I have migration this way. Will keep you posted.
I have some earwigs that have burrowed down in the tops of my milkweed? I’m new to the milkweed. It should I remove them? Isn’t this where the butterfly lays it’s eggs at the top down in the shoots?
Hi Rachel, we get a few of those and some weevils too. Since we have enough milkweed, I let them stay as part of a healthy milkweed ecosystem…if supply is limited, you can remove by dropping them into a soapy bucked of water.
Hi, I live in So. Ca. I had 3 milkweeds from last yr doing great, 3 weeks ago went out one morning and all had been nipped to the ground. Four days ago bought 2 more about 2 ft tall. This morning (so overnight) the stems have been “cut” about half way down, not chewed, even on a slate. Almost like someone was cutting the top for a floral arrangement. Clean cut. Did not bother anything else in the yard. I have a 6 ft fence around the patio. Can’t find anything on google. Ideas???? Thank you in advance
Hi Sandra, this sounds something a bit larger like a rabbit, deer, rat, squirrel. You could try putting fencing around individual plants….?
Can you spray something on milkweed plants before you see aphids…preventative ? Last year they destroyed my patch
Thanks
Hi Colleen, unfortunately no…organic treatments like neem oil will kill caterpillars. Check out this post for some short and long term strategies:
Stop Aphids from taking over milkweed
Hi- My tropical milkweed leaves have flatish, brown/ black specks on the back of the leaves. Looks like flecks of pepper. It doesn’t move or have legs. Unsure if its an organism. I remove the leaves and dispose. The specks smear a brown/red color color. Leaves intact but eventually fall off. It doesn’t look like leaf rust. It doesn’t look like any of the pests or diseases you’ve described here. I don’t know how to treat. Pls advise. TIA
Hi Nicole, potentially sounds like some type of fungus. I would remove the affected leaves and discard. More info on this page:
Milkweed Diseases
Hi Tony,
I have been raising monarch in Southern California with your help for 2 years. This winter, I have a problem getting my planted tropical milkweed to grow. Every time I get a crop of new little leaves, something is stripping them to the stems! I brought in the plants I had in pots, and I have been watering with hydrogen peroxide mix, but there is something that keeps eating my new leaves. I never see any milkweed bugs and I have the plants surrounded with wire fencing. There are no animals in the yard bigger than a lizard. What could be eating my new growth??
Hi Sue, sorry to hear about your missing milkweed leaves…if you’re not seeing the culprit it’s possibly visiting at night…I know there are some mice/rats/squirrels that have been known to eat milkweed in warmer regions, although that seems ‘unlikely’ because of the fence. I’m not familiar with all the wildlife in your region, but check out some resources here for ideas: Western Monarch Butterfly Resources
Rarely see a Monarch or milkweed in W.C. AL. Are there no Monarch’s because of no milkweed or do they just not live here? I do have a nice nectar garden with a variety of butterflies.
Hi Michelle, there are monarchs in Alabama, but not having milkweed would greatly reduce chances of seeing them. Here’s some info if you’d like to attract more monarchs:
How To Start a Monarch Butterfly Garden
Hello, I have been having a serious problem with some type of bug which looks to be burrowing through the leaves of my milkweed plants. The bug does not eat through the leaves, but you can see what looks like a trail going through the leaves. I am not sure which type I have of the milkweed, but I reside in zone 10 in San Diego, CA. I keep removing the infected leaves, but the problem still exists. The milkweed flowers range in colors from yellow to orange to red-orange. Crazy I never had this problem until I was assaulted and bedridden for over 1 1/2 years and my spouse had to take care of my plants. He has no clue how to care for plants and tells me he does not want to know. He is happy in his ignorance. He still does not know how to water my many types of plants. Either he over waters them, doesn’t water them enough or waters plants overhead which cannot tolerate getting their leaves wet.
As far as bugs I have seen on the various color milkweeds, they include orange aphids (Oleander Aphids), black small ants, various Preditors spiders, occasionally a green inch type worm/catipillar that bites, and Monarch butterflies and babies when there are no other bugs on the plant.
If you have any idea of the bug which may be tunneling through the milkweed leaves please let me know. Other wise I might have to take it to our local Agricultural Dept. to identify.
Hi Debra, this sounds like some type of leaf miner, but could be a species specific to your region. You might want to try posting a photo of the leaf damage in an insect ID group, where there are help insect experts:
Insect Identification FB group
Hi Tony, Central Fl. here and am raising Monarchs! Have my friends doing it also!
However we are having trouble raising Butterfly Weed.
The bottom leaves turn ‘yellow with small black dots’!
What can we do???
Hi Geraldine, when plants develop problems with fungus we remove the affected leaves and sometimes stems of the plants. Watering less might help. Here’s more info:
Milkweed Diseases
Hi I am fighting a battle with aphids on my milkweed by which I just smash as I do not want to hurt my eggs. But in the process I am finding a worm like thing (?) it moves pretty quickly, black and beige with some white on the middle of it. I have been killing them but I want some help in finding out what it is. Like I said I see it when I am smashing the aphids but I do not normally look at my milkweed too much except when it has aphids. I like in Fl so can you help? I have been raising Monarchs for 2 years now and let at least 100 go every year..
Hi Janine, I would try to get a photo and post it here:
Insect Identification
I have these white circle like pox on my balloon milkweed. Its casuing the stems to be deformed. I can squish them but its not effective. Im not sure what i have or how to get rid of it. Im not sure how to attach a pictures of it
Hi Heather, here’s info about milkweed diseases- prevention and treatment:
Milkweed Diseases
How can you rinse the milkweed the the caterpillar is on? And if I put one of them in a cage, do I rinse the stem and leaves then dry before placing new cutting in the cage?
Hi Renee, if you’re going to rinse or clean any milkweed, remove the caterpillars first. I don’t ‘dry’ leaves, just rinse and shake off. If your cage has good air circulation, they water will evaporate quickly and give the caterpillars some drinking water:
Caring for Baby Caterpillars
I found a line of metallic looking threadless string on the underside of a butterfly weed leaf. When I blew up the photo it appeared to be empty egg cases. I’ve never seen this before. I have a picture but don’t know how to attach it here.
Hi Kathy, is this the correct ID:
Lacewing Eggs
This is the first year I’ve planted milkweed and I was soooo excited. Now I’m not! I have several flower beds and have never had a bug/caterpillar problem. Now that I’ve planted milkweed I’ve seen so many different kinds of bugs and caterpillars it’s giving me the willies and I just hope they don’t infect my other flower beds. I did have one Monarch hatch and that was exciting but If they start infecting my other beds they’re outta here! Geez – peace and harmony has gone to the bugs…
Why an I seeing monarchs this year with deformed wings. Do they still survive.
Hi Carole, it’s possible they were attacked by predators or maybe they have OE parasites…deformed wings is a common sign. They will probably not be migrators.
I had one female eclose this year with one wing smaller than another. She lived only about a week. She couldn’t fly, so I kept her in a mesh cage and fed her flowers and sugar water. It was sad to see her go.
I had brought in eggs, so I don’t think she had OE. All the other eggs eclosed fine into big beautiful Monarchs.
But when she was in the J shape, a fellow cat got close to her which upset her. She began moving back and forth for a couple of minutes, never losing her silky footing before finally calming down again. When she formed her chrysalis, she fell. I think her silky footing had become loose enough that it couldn’t hold her up. I relocated her to a safe hanging position again. But I think the fall may have injured her enough to result in one wing being smaller than the other, and so she wasn’t able to fly.
Does that sound probable? Still, I don’ know why she lived only about a week.
I have the last group–six chrysalides–ready to eclose in the next day or two. So far, they all look fine.
Hi Connie, it’s hard to say. Keep in mind caterpillars get OE by ingesting spores from milkweed or from their egg shells so they can still get OE if all milkweed isn’t thoroughly rinsed. I’m not sure that a fall would cause a wing to be smaller.
I have a monarch that hatched from its chrysalis this morning around 8:10. It is now 5:40 pm and I’ve taken it outside a couple of times to see if it would fly. It just falls to the ground. It flaps its wings and walks around my lanai but doesn’t seem like it can fly. What do you think would cause it’s behavior? It’s now getting ready to storm so I don’t want to put it outside. What would you suggest?
Hi, I would keep it during the storm and try to release again if it seems stronger. If it is weak, it might have OE parasites:
Monarch Disease and Parasites
Yesterday I noticed that alot of the leaves on our milkweed plants were eaten off. So I went to investigate to find 31 caterpillars! I was so excited, I was picturing all the monarchs as they’re gonna fly around our yard before they take off. I checked on them today and this time counted 47 but plus one caterpillar that looked different. It wasn’t fuzzy like the others. I was intrigued and with some googling became disappointed to find out I did not in fact win the monarch jackpot lol. I’ve learned more about the monarchs and tussock moth now though.
Hi Jessica, when you see large groups, it’s likely tussocks. Like monarchs, they have many predators in the garden and can disappear very quickly.
Hi Tony,
What will consume serious amounts of tiger milkweed caterpillars? Nothing seems to have disturbed mine while they destroyed the milkweed.
Thanks,
Eunice
I’m not sure Eunice, but I’ve seen large groups disappear from our plants before. these are common monarch predators:
13 Monarch Predators
Hi,
I have these Tussock moth caterpillars and the Monarch caterpillars in my milkweed garden. I have moved the Tussock moth caterpillars down to the other end of the garden, but they keep finding their way back to where the monarch caterpillars are. What else can I do?
I have pictures, but not sure how or where they can be posted.
Thank you!
Lindsey
Hi Lindsey…plant more milkweed for a long term strategy. For now, tussocks have a lot of the same predator issues that monarchs do, so they might be the answer. If you have enough milkweed I would let them stay. Otherwise, they also eat dogbane, which is not a monarch host plant.
Thank you, Tony! I will plant more milkweed. I will let them stay?
Tony,
We noticed today under one of our Swamp milkweed, on the ground around the stalks and plant were these pebble looking items not present when I planted them 3 wks ago.They are tan on the bottom, white on top, some appear opened (hatched?) which are grey. The other 5 plants show no signs of this.The kidlets compare them to tiny acorns. The milkweed has white flowers and appears to be healthy otherwise. We live in Michigan. HELP
Hi Trixi, I’m not sure what you’re describing. i would take a photo and post here:
Insect Identification
I am beginning a project to propagate the milkweed plant. How do I protect the plant from both the bugs listed here and the monarch so that they can be sold in good condition to customers. I am using both seeds and cuttings.
Thank you,
Hi Alejandro, you could always cover plants with netting. You might want to contact a nursery for specifics, as I’m not a commercial grower. good luck!
Thank you for all you do. Just answering our questions must be a full time job. Sometimes the comment section will give me the reassurance I need.
I believe this year I have found everyone of the insects listed above on the different plots/species of milkweed. Luckily the Monarchs are still finding places to lay their eggs.
Again, thank you for all you do. I know when I have questions, the answer is somewhere in your books or website!
I live in Southern California and I have a huge problem with my milkweed infestation of aphids. I had read somewhere that they don’t like banana peels.
Well, yesterday afternoon I ate a banana and sliced the peel thinly and hung it in various places on the milkweed. Today, I walked out and no more aphids!
Now, how to get rid of the red bug infestation? My milkweed all look so sad and unhealthy.
Hi Monica, if you’re talking about milkweed bugs (also listed in the post) and you have a serious infestation, you could try the soapy bucket of water recommended for dealing with adult Japanese beetles…good luck!
All insects, not just monarch butterflies, and other organisms that eat milkweeds are welcome on the milkweed plants on my land. These other insects that also need to eat milkweed to complete their life cycles are not the problem that is causing a decline in monarch butterfly populations.
Big agriculture and big suburbia are the problem for monarch butterflies. Tackle those problems instead of killing insects that are just doing what they have always done for millions of years.
Hi Gary, thank you for your reply…there are options listed here that don’t involve killing bugs. I often point out several times that unless there is a serious infestation, other milkweed insects are part of a healthy ecosystem.
Excellent information!!! Thank you!!! Do you have a source you could recommend for milkweed seeds?
Hi Jenna, check out this page for some options:
Suggest Milkweed Stores
Thank you!!!
Best Non Toxic way to attract, catch and kill slugs and snails.
Cat food can or large deep container lid that has edges 1/2 inch or deeper, bury so edge of container so little or non of the edge is level to the ground where the plant(s) are. fill with any kind of beer…..yeast attracts them in and they drown.
I haven’t seen a slug or snail for last 15 of the 26 years in my yard.
Never saw a caterpillar of any kind in the beer trap.
Check your local parks for pods that have browned and opened and collect them for free! Then you know your’re getting the variety that work well in your climate.
My milkweed plants leaves are being completely stripped by a wormlike, 1/2″ long, black bristles sticking out and some orange on it. I don’t use chemicals. Suggestions please.
Hi Shirlie, this sounds like the tussock moth caterpillars listed on this page. We let them stay, but you could always move them to less desirable milkweed plants…they eat dogbane too.
Do the tussock moth caterpillars cause a skin reaction if handled? My milkweed plants are close to my house and the caterpillars aare all over the plants AND the nearby sidewalk.. My grandkids are fascinated by the caterpillars but I dont know if I should let them handle the fuzzy-looking creatures.
Hi Charlotte, I think it depends on the species of tussock moth caterpillar. I would photograph and get it ID’d in a group like this:
Insect Identification
I have milkweed in my front yard that have black feces looking stuff on them.What is it and how do I get rid of it? Thanks
Hi Melanie, it could be fungus. At this point in the season, you might just want to cut back the plants. Here’s more info:
Milkweed Diseases
Hi Karen, congrats on attracting your first monarchs. It’s hard to tell from the photo, but they might be hoverfly larvae. They are beneficial insects that eat aphids. Compare photos to verify:
Hoverfly Larvae
Thanks for the speedy reply Tony!! I found some post/images of the hoverfly and thought that’s what mine might be but the photos I found (and the link you sent) show them as being more green than mine but they are the closest looking caterpillar I could find. I will keep an eye on them. I also read they are beneficial for eating aphids, etc. but I thought I also read that they eat caterpillars and possibly monarch cats when they’re very small which of course has me concerned given they’re on my milkweed. Do you think I should move them to another plant?
I think I have a moth larvae infestation. I’ve seen Monarch caterpillars on other milkweed but one of my plants is being eaten. What should I look for to determine if these are harmful pests? Since I’m in Wisconsin things are just now hatching!
Hi Sara, if you are talking about tussock moth caterpillars, you should be able to see them easily on the plants. They hang out together in mass groups…
I’m confused. I have several milkweed plants that have done fine, so far, Now I have caterpillars on them. Are all cats bad for the plant? I’m in South Florida
Hi Linda, they will eat down the milkweed leaves and sometimes the stalks, but it will grow back.
Good Morning from central New Jersey, where the monarchs are in abundance in our yard (I’m actually getting way too many eggs laid on my 4-6″ tropical m/w and for now they’re leaving the other varieties alone! LOL)
My question has to do with leaf curling/distortion on common m/w. I belong to the Monarch Teacher Network group and someone offered that it is leaf curling midge. I’ve tried looking them up on line, but can’t find any pictures of milkweed damage. Any thoughts on this critter and milkweed? Trying to post a pic, but not sure it’s coming through.
Bruce
https://www.facebook.com/photo.php?fbid=10211832228752741&set=pcb.1382205828494752&type=3
Hi Bruce, that looks like potential damage from:
Milkweed Weevils
They have never been a serious pest, so we’ve only cut back affected foliage. We’ve had worse damage from the the species that is specific to swamp milkweed. Since they are nocturnal and their larvae feed inside the stalks, they can be a difficult pest to deter…
I saw on the teacher site someone ID’d as ‘leaf curling midge’. I am not familiar with this, but it sounds like a definite possibility. Weevils cause leaf deformation, but it’s not usually that extensive…
Hi Bruce,
I too am having the same issue on some of my plants. Common and Calotropis Gigantea are the only ones to be affected.
I too am in NJ (Central Shore area).
I don’t see anything actually on the leaves so still a big fat question mark.
Still not sure if I should feed the plant to the cats (not all leaves are affected). I haven’t tried yet…
Hey Tony & any one else looking for spider mite control & relief,
These pests have been my biggest trouble makers of all the pests. I’ve tried everything & finally, I found something that works & wont harm my cats. It’s called Mantis Plant Protection & found on Amazon for abt $20. It’s made up of a mixture of essential oils & only meant to kill spider mites, & soft bodied insects, won’t even kill 1st instar caterpillars. It even kills the oleander aphids. I’m so happy & wanted to share w/ you guys here. It hasn’t harmed my plants & literally after spraying the leaves, the spider mites & aphids are dead, just rinse them right off. Mama monarch even stopped in & laid some eggs right after spraying some of the leaves that weren’t rinsed yet & she didn’t seem to mind or have any issues w/ the spray.
The Mantis Plant Protection says it won’t harm other insects so it shouldn’t harm her or the eggs either. I accidentally sprayed leaves & found 4 1st instar cats squirming in the liquid, I rescued them & brought them in the house, they dried off & climbed on a new leaf & survived. They’re growing big & strong right now. I hope this is helpful info for you guys! Happy butterflarming w/ spider-miteless plants ???
Hi Tracey, thanks for posting your experience…however, caterpillars is included on the their pest list so I would not recommend:
Pest Spectrum: Spider mites and soft bodied, piercing and sucking insect pests such as: aphids, beetles, caterpillars (early stages), flies (maggot stage), spider mites, mealybugs, scale (crawler stage), thrips and whiteflies.
I’m having the same problem with spider mites They are taking over all my plants!! Also the fungus called ‘Rust’ I’ve been growing milkweed for 2 years & this year I had soooo many caterpillars ? I had to go buy more milkweed!!( It was AMAZING! We had over 15 chrysalis ( that we could find) and the whole family was as excited! ). Anyways, the store bought milkweed brought the spider mites with a vengeance….I’m finding little caterpillars but no more eggs and every baby cat is surrounded by spider mites & or rust!! I have to do something but afraid of killing my babes & eggs!! Please please help!! I’ve tried alcohol in the past with aphids but it was ineffective.
Will the rust kill the caterpillars? I’m sure that spider mites will. by looking at my plants it looks like they are killing them! Can’t believe the caterpillars could survive much longer without my intervention! ASAP.
PS you web site is a wonderful resource and I use it when ever I’m in the need to know… thank you so very much!!
Hi Sandy, I would use stem cuttings so you can thoroughly rinse the mites off the milkweed. Here’s more info:
Using Stem Cuttings to Feed Caterpillars
Hey Tony
You might want to add Earwigs to the list. They can be very destructive. Hard to find since they hide during the day and eat at night.
Typical is to find the top portions of a stem wilted and hanging over. That and randomly chewed up portions of leaves. The Earwigs tend to eat the top portions of the stems – I discovered them wondering what was harming my Milkweed. I suspected Earwigs. Went out at night with flashlight and sure enough – found them chomping on some Swamp milkweed.
Here is what they look like:
https://msue.anr.msu.edu/news/earwigs_bane_of_summer_garden_plants
Thanks for the info David…they are next on the list!
For earwigs– roll up about 4 sheets of newspaper and get them wet. Lay these on the ground and the earwigs will crawl in. Then you can burn the newspaper or otherwise dispose.
I’ve been growing tropical milkweed for several years now here in Tulsa, OK. This year I have a grub-looking thing eating the leaves off my milkweed, stripping the leaves completely. They are about 1/4- 5/16ths inch long and nearly the same in width. They vary in color from white to pinkish. So far, they’ve only attacked one plant, and I’ve squashed about 20 of them. The plant started sprouting leaves again, but today I found 3 more of them on the plant which stripped the leaves again. What are they?
Hi Don, it sounds like you are talking about swamp milkweed leaf beetle larva
I have the same thing. I will definitely take a picture if another one shows up. I bought some of the tropical milkweed that can’t survive the NE winters so I’ve kept them in planters so I can bring them inside when it gets cold. These are the ones that have the bugs on them ~ the ones in my garden are doing great (so far, knock on wood). I just bought some praying mantis eggs (they are supposed to eat weevils?) and a bag of lady bugs (I have an aphid problem all of a sudden) and a box of bumble bees. I’m taking no prisoners here!!
FYI
List of Pests and Predator Insects
Here’s a list of garden pests and predator insects that can be used against them. My local stores carry some of these and you can buy some at Planetnatural.com.
Insect Pest Insect Predator
Aphids Lacewing Ladybug, Minute pirate bug, Praying mantis
Cabbage loopers Parasitic wasp
Caterpillars Minute pirate bug, Parasitic wasp
Cutworms Parasitic wasp
Flea larvae Beneficial nematode
Flies Fly parasite
Fungus Gnats Fungus gnat predator
Grasshoppers Praying mantis
Grubs Beneficial nematode
Leaf hoppers Lacewing, Ladybug, Minute pirate bug
Leafminers Leafminer parasite
Mealybugs Lacewing, Ladybug
Mites Lacewing, Ladybug, Minute pirate bug, Predatory mite
Mosquitoes Praying mantis
Moths Lacewing, Praying mantis
Root weevils Beneficial nematode
Scale Lacewing, Ladybug, Minute pirate bug
Slugs Beneficial nematode
Snails Beneficial nematode
Thrips Lacewing Minute pirate bug
Tomato hornworms Parasitic wasp
Whiteflies Minute pirate bug, Whitefly parasite
releasing large numbers of predatory insects into your garden can have unintentional consequences to your local ecosystem and even to monarchs themselves. ladybug and lacewings larva will both eat monarch eggs and caterpillars and parasitic wasps aren’t specific to one caterpillar species. It’s better to attract these predators naturally over a long period.
Fo slug or snails– take a shallow dish or plate that lets you pour about 1″ of beer into the vessel. Slugs and snails drink it, get drunk and drown. Does not effect the ecosystem.
unfortunately, mantids also eat monarch caterpillars and butterflies
Hi Tony,
I have noticed on the tips of my milkweed, these black egg looking things. Along with them, I see an ant or two, and a tiny fly that looks like a gnat. What are these things? I had to pinch the tips off of a lot of my otherwise healthy milkweed. These bugs look like they are about to do damage to my modest crop of milkweed. Do you have any idea what they are? I know they are not the usual aphids, or the milkweed beetles, but they are nasty and look like clusters of small dirt pebbles or caterpillar poop. The Monarchs have not found my gardens yet and no eggs.
Hi Daisy, I’m not sure what you’re describing. If you’re on facebook please post a photo on our facebook page:
Monarch Butterfly Garden Facebook
I also just spotted these very tiny black eggs(?) on my milkweed. The entire plant is healthy, except for the top growth. In which the new leaves are all curled. When I uncurled them, I noticed the patches of these very tiny black eggs(?). I tried to look them up, but found nothing. I washed them all off and am hoping never to see them again. It did look they were causing damage.
Thanks Tony,
Jeri
Hi Jeri,
What you describe is identical to what is happening on my milkweed. I didn’t want to use anything on my milkweed to get rid of these awful black things. What I did was pick off the affected tips of the milkweed and put it on the sidewalk and rubbed the bugs away with my shoe. It took me a long time to establish a nice patch of milkweed and I am not going to let these nasty bugs destroy it for my Monarchs. I had found 4 eggs (Monarch), and one just hatched around noon today. The other 3 will follow by this evening.
I tried looking at the bugs under my microscope and they look like black aphids, but that doesn’t explain the itty bitty black flies that are there too.
I am confused on this.
Hi Daisy, I have started seeing these tiny black flies on some of our milkweed too…I also saw a lacewing larvae carrying one around on the golden alexander. I usually don’t remove any bugs from milkweed unless they are an imminent threat to monarchs or destroying the milkweed. If you remove all the other bugs, monarchs will become the main course for visiting predators.
I’m also experiencing the same black gnats and black egged on my common and on my swamp. They don’t seem to bother my tropical or tall green. I keep squishing them. My milkweed is in great condition except for the little black flying gnats and the black eggs in the small tend part of the milkweed plants. Is this something new we are experiencing. Would be interesting to see what states are being affected. I’m in Beach Park Illinois
Hi Noni, I can’t recall seeing them before in Minnesota. The good news is I saw a hoverfly larvae carrying one off so they do have predators. I’ll be sure to post more info when I have some…
I’m in Michigan and my milkweed has them too
I have a problem with my milkweed patches that I can’t seem to solve and I’m not sure if what’s happening to my plants is the result of any of the pest listed above. My plants develope nicely to a point and then something sticks it and causes the upper portion of the plant to wilt and die. It looks as if the plant has been cut. Please help. Matt.
Hi Matt, there are insect pests and then there are also larger pests that can inflict instant damage like rabbits or deer. In the case of animals, fencing is the best option if possible. If the tops of your plants are wilting, it could also be a fungus. Here’s more info on dealing with milkweed diseases:
Milkweed Diseases, Prevention, Treatment
If it’s an insect pest, it will be easier to suggest a course of action if you can ID first…good luck!
Everyone says that the swamp milkweed beetle is not a serious problem but it has been in my milkweed garden for several years. I noticed that when the beetle eats on a milkweed leaf, the leaf dies. I been hand collecting the eggs, nymphs and beetles for years but there hasn’t been very many of them.
This year the damage is happening very early in the spring. The young plants coming up are drooping and dying. I noticed on one leaf of each plant is a small hole. This leaf dies first and then the whole plant dies. It is too early for the swamp milkweed beetle but the plants seem to be dying the same way. Any ideas?
Hi Shirley, I’ve already seen one in Minnesota, so they might be back in your garden too. It’s possible your plants could have some type of fungus or perhaps your plants need to be divided (swamp milkweed). here’s more info on diseases:
Milkweed Diseases
I only grow common milkweed and the swamp milkweed beetle has been a problem but I haven’t seen any yet. I did find a new bug that is causing the problem and must have been around for a couple of years. It is the Milkweed Stem Weevil. I saw it doing the damage. They are going to be hard to find because they are nocturnal.
Hi Shirley, thanks for the reminder. I will add more info about them to the page soon.
I have planted my first ever milkweed plants that I raised from seeds in February. They looked good for the first month but now the bottom leaves are turning reddish then yellow then falling off. I’m just sick about it because I can’t figure out what is causing it. There are no bugs and the leaves don’t have fungus on them. I’ve read everything I can get my hands on about this and it seems it could be overwatering or underwatering. Which is it? I’m afraid all that work in raising them will be for nothing. We don’t typically have Monarchs here until next fall but I still want to have them available. Help!
Hi Andy, are you growing plants inside under grow lights or are your seedlings outside?
Hi! Something has devoured my milkweed! It has eaten all the flowers and leaves and has even been munching on the stems. I hadn’t seen any insects on the plant prior to the leaves disappearing. We live in FL so there are lots of lizards and squirrels. Any ideas?
Hi Tammy, bigger pests include mice, deer, rabbits…I recently saw a photo of a squirrel eating milkweed so this is also possible, but I’m not sure how often this occurs. Rabbit/Chicken fencing might help, depending on who the culprit is…
When I plant the seeds about how many month do I need to keep it inside ? My seeds are quite tiny so I guess I should put 2 or 3 together, I got the seeds from a monarch milkweed plant and those ones are giant, about 1 or 2 metres, I was wondering how can a tiny seed grow that big!
Hi Jolin, soak the seeds in water 24 hours before planting and they should germinate faster when you plant them outside…you can also germinate them directly in water if you leave the seeds in longer:
Swan Milkweed Info
Balloon Plant Info
Water Stratification (this method works for both species)
Hello, I live in Quebec Canada
In argricultural land, we had an infestation of lady bugs for many years
I dunno if farmers spread that on fields to help crops but my house is white and it attracts them like crazy
But the past two years has gotten better however, now I have a new pest for two years I just found the pic of what they are and it’s milkweed bug
With red backing
I don’t think we have milkweed plants
And they are no my house
Even in clusters on the gravel and foundation of house
It’s so annoying
Why do I have this…
Help help help
Hi Carol, are you sure they’re not boxelder bugs?
Boxelder bug photos and info
Thanks, Tony, for the photos of the Milkweed Assassin Bug eggs. I will begin hunting them down amongst my evergreen day lilies. That’s where I have seen them during the winter. I am worried that we will be overrun with them because we’ve barely had a winter down here. I already had plans to bring some “cats” inside this year so I will be looking for their eggs too.
Thanks for all you do!
As late in the season as it is, I have more than 25 cats in varying stages of development. I’m in Southern California, so I guess this is common. My problem is my milkweed is suffering from leaf miner infestation and I’m afraid I won’t have enough to feed my brood. What, if anything, can I use to kill them that won’t hurt my cats. I keep them in the greenhouse, but that’s not enough to keep out the pests I guess. I can’t find any new plants now either.
Hi Hollie, the only organic treatment suggestion I found was neem oil, which is sytsemic and will kill monarch caterpillars. I would use the leaves as they are…good luck!
I have these insects in my garden all year round. I have heard they are Butterfly Weed Assassin Bugs. I have not seen any evidence of them hurting my plants but they eat aphids. I thought that was a good thing since my butterfly weed is usually covered with aphids. Upon further research I found out that they eat Monarch eggs, caterpillars and butterflies. Now I’m torn as to whether I should let them live or what. They have also found my Gulf Fritillary area where I grow Passion Flower vines and they get those caterpillars. (When in season) I’m in NW Louisiana. I’d love to hear from other butterfly lovers about this.
Hi Dianne, I try not to mess with the local ecosystem unless something is taking over the garden. If I found assassin bug eggs on milkweed I would remove them, but otherwise I leave them alone in our northern garden. A fun and educational way to boost monarch numbers is raising them indoors for release. In the garden, less than 5% of monarchs survive to reach butterhood, while the indoor rate can soar to above 90% if you have a good system in place…
Assassin Bug Eggs
Hi Tony,
I love the information you provide on your website. Thank you. 2016 is my first year with planting milkweed either plants or seeds. Although I only had one monarch male I enjoyed starting my gardening project. I am noticing on my Butterfly Weed an orange and black bug. I have learned it is the Milkweed Bug. Oncopeltus fasciatus This big bug and the little ones are only on the seed pods. It’s late in the season, should I just leave them or would it be best to get rid of them? Are they hurting the pods? I look forward to your advice. Thank you so much!!
Hi Shannon, I personally let them stay in our garden. The exception would be to remove them from plants/pods I want to harvest seed from because they can negatively affect germination rates.
I raised milkweed from tiny seeds and finally planted the juveniles about 2 weeks ago. Something dug them up, but I caught it in time and fixed it, sprinkling cayenne powder around them . Then the critter dug a tunnel under them, so I sprinkled cayenne powder down the hole. Everything was OK until I went out this morning and something had eaten all the leaves off, leaving only the stems. What do I do to bring them back next spring? I’m thinking of covering them in mulch for the winter (?) but then what do I do in the spring? Is there any way of saving my babies?
Hi Diane, sorry to hear this! it sounds like you could be dealing with a vole or gopher problem. Rabbits will also eat milkweed plants…especially seedlings. Fencing works for rabbits, but you will have to research other methods for dealing with gophers or voles. good luck…
PS…milkweed is resilient. If you have good roots on the seedlings, they should come back if they are not disturbed further.
Hello,
I recently purchased a few butterfly weed plants for my garden. They are blooming, but I am noticing that a lot of the leaves are being eaten and there are little black eggs under some of the leaves. I want to spray the plant with some bug insect spray, but I don’t want to end up hurting the plant and/or the butterflies by spraying the spray. Checking with your first. Thank you for any help you can give me.
Debbie
Hi Debbie, I would not suggest spraying before you ID your mystery eggs. Also, any foliar treatment you leave on milkweed plants will probably repel monarchs, even if it won’t ‘harm’ them.
Thanks Tony! I am noticing some caterpillars on my butterfly weed. I take it this is a good thing. I think at this time I will leave the plants alone. I do notice munched leaves and some plants are looking skinny from the nibbles of leaves from the caterpillar. Is that normal also? One more thing, if the milk weed pods are kind of brown, is that normal?
Thanks for any help you can give me.
Debbie
Hi Debbie, monarchs munching on your milkweed is always a good thing in a butterfly garden! Native milkweed fades at the end of the season, and the seed pods often turn brown. This is a normal part of the milkweed growth cycle.
Ok, Great! So the caterpillars are munching my plants to look very skinny and no longer full plants.
That is normal? I shouldn’t worry about it. That is natural for this plant?
Thanks, Debbie
Hi Debbie, 1 caterpillar can devour an entire plant in the two weeks it’s in the caterpillar stage. It’s important to have a good milkweed supply on hand to keep up with demand. Perennial milkweed will grow back.
I have tusoc moth catipillars on my milk weed. I sprayed them with mint oil and they are dead. I only pray the leaves they are on but I’m hopine I did not run off the monarchs
Hi Rebecca, if we have an overabundance of tussocks, we just move them to older milkweed plants. Any foliar treatments should be rinsed thoroughly to avoid harming or repelling monarchs. good luck!
HELP!!! The leaves on one of my milkweed plants is infested with very very small red bugs (smaller than the Oleander Aphids which some of my plants have). They are on almost every leaf. The leaves that are more infested are almost pale? The bugs aren’t actually eating the leaves. It kind of looks like the bugs are sucking the nutrients out of the leaves. But any idea what they are and how to get rid of them?
Hi Julie, it sounds like spider mites and there is info posted about them on this page. good luck!
Last year all the monarchs we raised & released were healthy. This year we have lost so many to tachinid flies. Why would there seem to be an increase in the flies this year? Could it be the unusual heat & humidity, above average days with 90+ temps? We don’t use any pesticides anywhere in our yard & have no intention to do so but dealing with these flies is something new to us & disheartening. Any suggestions would be appreciated.
Hi Susan, this year was the opposite for us as the tachinids missed us completely…I wish I understood WHY. Your best bet on avoiding them is by bringing in eggs or very small caterpillars. The larger the caterpillar, the more likely a tachinid found it before you. You can still bring them inside, but monitor closely and discard any tachinid fly maggots/pupae if they emerge from a monarch.
Thank you for a great resource! I’ve learned a lot in these pages.
I have two questions, please.
First, can Monarch caterpillars find their way from one milkweed plant to another? I have a few plants spaced anywhere from 6 inches to 2 feet apart. Right now, I think I have a few instar 1 little ones, and I assume they’re not big enough to travel to another plant yet, but when they’re bigger?
And I tried someone’s suggestion about using fresh coffee grounds to deter ants. It didn’t work; apparently, my ants like a jolt of caffeine.
However, I’ve managed to get the aphid problem under control, which was leading to the ant issue. I sprayed them off at first with water, but a few hours later they were back–just lower down on the branches. So I used a few Q-tips and plain water the second time. That worked, though I’ve followed up the past couple of days to catch remaining aphids.
Secondly, am I correct that removing most of the aphids from the milkweed will discourage the ants from getting to the Monarch eggs and caterpillars? Or should I still be concerned with the ants? I don’t see as many ants on the plants since I removed the aphids, so I’m hopeful I don’t have to take further measures against them.
I have netting ready to protect the caterpillars from birds and wasps.
Thanks very much!
Colleen
Hi Colleen, the caterpillars should be able to find milkweed plants in close proximity. I’ve heard mixed reviews on the coffee grounds for ants…sorry they aren’t working for you. Ants are monarch egg/caterpillar predators. A better way of long-term pest management is not to manage them, but to spread out milkweed patches and plant different species of mw….and, of course, bringing in a few to raise indoors. A healthy ecosystem includes monarchs, milkweed pests, and predators. Netting can be helpful against birds/wasps…good luck!
my plants are being eaten to bare stems by the caterpillars of the moth you described. as of yet i have not seen any monarch caterpillars. if there were any the little buggers would have eaten as they strip the plants of all their leaves.
Hi Dorothy, they certainly eat a lot! if you have room in your garden, plant several species of milkweed and space out your patches so there is room for monarchs, pests, and predators…this creates a healthy ecosystem in your garden, and you won’t have to worry when the ravenous tussocks show up.
Yes can you use floral foam the green kind florist use to soak up water and design flowers in for the varies butterfly weeds instead of tubes? It would mean a dish of water for the foam to sit in instead if floral yubes that need more filling of water;)
Thanks’
I think you need to be very careful in advising folks to control milkweed “pests”. Managing an ecosystem, and milkweed patches are ecosystems, for a single species is rarely a good idea. The best advice you give is to plant as many milkweed plants as you can, keeping in mind that you should only plant species native to your area, so that there is enough for everyone. Killing other native species of milkweed feeding insects, however, is not likely to make much difference to overall monarch survival, which is imperiled overwhelmingly by large scale human activities and could, as you note, have unintended ecological consequences. It would be best for us not to pick winners and losers in the competition over individual milkweed plants or patches, other than taking some caterpillars in to raise indoors.
Hi Cliff, the intent of the post is to make people aware of other options that can help support a healthy ecosystem. While our focus here is monarchs, we support other garden wildlife, including some milkweed “pests” Tony
Hello Tony
I love your website, lots of great information. I also have had a lifelong fascination with monarchs and still enjoy raising them after 40 years. I have recently found a tropical milkweed that the monarchs absolutely love. Its scientific name is Asclepias Physocarpus and its common names are Giant Swan Milkweed, Milkweed Balloon plant, and Hairy Balls milkweed (when you see the seed pods you will understand why the last name listed is relevant). It is big enough to host a whole crop of caterpillars and the adults love the flowers. The seeds are available on amazon. And the milkweed Beatles do really squeak when you grab them. Once again great website!
Hi Eric, we have a couple Gomphocarpus physocarpus (updated botanical name) growing in containers this season, as well as Gomphocarpus fruticosus growing in the garden:
Gomphocarpus fruticosus
Thanks for your kind words and beetle squeak confirmation. Have a great season!
Hello I’m haveing a problem with 2 newly acquired milkweed so when I first got them they had a few leaves with brown spots which I thought they were just old leaves so then a few days later I saw a few monarch caterpillars on them and I moved them into a screened porch to protect them. The next day I saw a few caterpillars with thier heads blackened and somewhat melted and they were still reacting to my touch. So I move the still healthy caterpillars to a habitat and fed them leaves from healthy milkweeds. Today I sprayed some soap on the plants to kill off the aphids and notice most of the leaves on the 2 milkweed have numerous brown spots on the bottom of the leaves and a white coating on top of the leaves that looks like someone got a bit of white spray paint on them and what seems to me to be spider mites. What can I do to save the 2 milkweeds and get rid of the insects? And can u awnser what caused the monarch caterpillars to blacken and melt?
Hi Dalton, it sounds like your caterpillars might have NPV (a virus). Here’s more info about NPV prevention:
Monarch Diseases and Prevention
Here’s some info about treating spider mites:
Milkweed Pests and How to Get Rid of Them
Hi Tony,
It’s been a lot warmer than normal here in Michigan, and I spotted my first milkweed bug running around the garden on Easter Sunday. I don’t know its correct name, but it looked just like the one in the picture above (bugs in love).
I would assume that the one I saw was an adult? I have no idea what it has been eating, but even the milkweed on the south side of my house wasn’t up, so I guess these little guys can survive on plants other than milkweed?
They must also bury themselves under the mulch at night because they survived some really cold nights (lows in the 20’s) earlier this month. Tough little bugs. It’s a shame that they are pests, because I love their color.
Brian
Hi Brian, in our region I don’t consider milkweed bugs to be a pest as the numbers don’t get out of control, and we have more than enough milkweed to spare some plants. They also have predators in the garden so keeping them helps to support the ecosystem.
Will the assassin bugs eat the aphids? Or do I need to get rid of both?
Hello Hillary, assassin bugs eat aphids, but they also eat monarch caterpillars. You’re usually better off planting more milkweed patches, and more milkweed species instead of trying to get rid of pests. You can’t really use foliar treatments on milkweed. Even if they aren’t toxic, the monarchs will probably bypass the plant for untreated plants. Here are 10 ideas to get rid of aphids naturally:
Stop Aphids from Taking Over your Milkweed
Overnight something stripped all the green growth from 3 small milkweed plants. No aphids. What could have done that. Wanted to start a butterfly garden. Afraid to try now
From Vista, CA
HELP and thank you
Hi Lynne, I’m not sure what pests are in your region but mice, rabbits, and deer have all been reported to eat milkweed, even though they’re not supposed to. We put up a rabbit fence this season and it made a huge difference…no more rabbits in the back yard garden!
WOW okay I do have mice. A fence it is. I would get a cat but I have a ton of birds. I guess I don’t have enough owls.
Thank you a million butterflies.
A ground hog strips the lower leaves from my milk weed plants. I’ve seen her do it here in New Hampshire.
My Swamp Milkweed are infested with Aphids. I’ve had NO luck finding the “Summer Beauty” Allium plants (bulbs) you recommended that has a scent that repels aphids. No nursery around me or online seems to carry them. Tony, WHERE do YOU get your plants or bulbs?
Hi Mary, I got ours at a plant sale in Minnesota. There are links on the allium page to buy online if you can’t find them locally. Hope this helps:
Summer Beauty Allium Flowers
I have been collecting catipilers the last two days, and there are alot on my first year milkweed, but they are dying, and they seem to be trying to start there next stage to early. About 3/4 the size they should be. And some are just dying. what is hapening to them. anybody now.
Hi Tom, here is some info on monarch diseases that might give you some ideas:
7 Common Monarch diseases and Parasites
If you bring them in too soon you will have to have plenty of plants in your cage for them to eat and they do eat a lot
HI,
the milkweed in my side garden often has aphids and ants on it. I have seen the ants attack various other insects to protect their aphids and I suspect they do the same to the monarch eggs/larvae.
Although I’ve seen monarch caterpillars I’ve yet to see one survive to chrysalis. I don’t know how to stop the ants, short of relocating the milkweed plants to a different section of the yard.
What can I do?
Thanks,
Hi Marina, if you plant several patches of different milkweed species around your yard/garden the predators won’t find them all. You could also try bringing in a few monarchs to raise indoors. Outdoor survival rate is less than 5%. If you follow a good raising system indoors, survival rate can surge to over 90%.
Thanks for this info about bringing them in. This year the Tussock moths have almost totally devoured our giant milkweed plant so I am worried about the Monarch caterpillars. I carried 4 in last night but they are not happy in the glass jar that I put them in. One wandered out and may be planning to make a chrysalis soon. The other is very tiny. I may have to go searching for other milkweed plants. Next year I plan to start early getting rid of Tussock moth caterpillars as they are so voracious. Also, we aphids are terrible this year so I am going to try some of the ideas here for getting rid of them too. What a battle to keep a few Monarchs alive at 8,000 feet in Colorado.
Hi Alice, sorry to hear the pests are taking over. As a long term strategy, try planting several varieties of milkweed and spread them out…that typically leaves you with some good milkweed.
Many of my various milkweed plants have an orange powder-like substance on the leaves. I can’t tell if this is normal or if the leaves should be cut back to remove this
Hi Teresa, I remove any milkweed leaves that look sick or fungusy. You say the substance is orange…could it be aphids?
Stop Aphids from Taking Over your Milkweed
Tony,
Do you think we’re done seeing eggs in the metro for the year. We had a goal of rearing and tagging 50 Monarchs for the migration. Have not seen any eggs or 1st/2nd instars in a week.
Bryon
Hi Bryon, we’re still get eggs on swamp milkweed pods and tropical milkweed. Other natives like butterfly weed and common are probably done getting eggs for the season. You can keep checking through this weekend…good luck!