How To Stop Losing Small Caterpillars
Keep Your Baby Caterpillars Safe and Secure
Raising monarch caterpillars is an exciting spring and summertime activity for gardeners of all ages. After raising monarchs for over 40 years, my survival rate has climbed over 95%. (The survival rate for monarchs outdoors is less than 5%.)
If you’d like to increase the survival rate of your small caterpillars, try this technique for raising monarch butterflies and watch your survival rate soar over 90%!
One of the most important decisions for raising monarchs will be your butterfly habitat, aka caterpillar cage. I’ve tried more than a few over the years and you might be surprised to learn what I use for a ‘starter’ cage.
Sealed Food Containers
While sealed food containers aren’t a good option for large caterpillars because you can’t use milkweed cuttings and the environment too humid, they make for an excellent hatchery for eggs and small caterpillars.
Sealed food containers offer a simple way to keep track of small monarch caterpillars. Here’s how my system works:
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Set Up
- Make sure you have access to at least 3 good-sized garden or potted milkweed plants
- Relocate monarch predators from these plants while you’re waiting for eggs
- Look for monarch eggs daily, regardless of whether you see mama monarchs fluttering around…they often come in and leave quickly!
- Once you find eggs, collect and protect them in your sealed food container
- Wait for your eggs to hatch
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After-Hatch
- make sure the leaves in the food container don’t dry out (this shouldn’t be a problem in a sealed food container)
- transfer them to a mesh cage after 3-4 days (or when you can easily see them)
- Clean out food container so it’s ready to host future small caterpillars
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Tips
- Don’t crowd food containers with too many eggs or unhatched eggs may be eaten by baby caterpillars
- Milkweed leaves can be gently rinsed off with the egg attached.
- Don’t place food containers in direct sun or you will cook eggs and small caterpillars 🍳
- Check on eggs and small caterpillars daily
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Pros
- You’ll never lose a small larva in a sealed container
- Less time intensive than daily switching dried out leaves
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Cons
- I’m not sure there are any. Since we started using these hatcheries, we’ve never lost a small caterpillar.
Sometime during the first week, you’ll want to move your growing caterpillars to a more breathable mesh cage. Check out some of the best cages for monarch caterpillars.
I have a butterfly cage. The caterpillars keep climbing up the side of the cage even though they are small. (They are not full grown yet.) They stay there overnight and the next day. Why do they do this and should I take them down and put them back down on a fresh leaf?
Hi Judy, if the milkweed is fresh and they’re not overcrowded, they sometimes leave the milkweed to molt (shed their skin). They will crawl back to the milkweed when they are finished, and that can take up to 24 hours. I would leave them.
Hi Tony, glad to find this post! I am new to monarch caterpillar raising. I am from Florida, and decided this year to start planting only native plants. I bought a couple swamp milkweed in gallon containers from a plant sale, which had monarch eggs on them. I planted the plants in my front yard and ended up with 9 tiny caterpillars! I was then faced with a dilemma: my new tiny plants would not be enough to sustain so many babies into adulthood, so yesterday I purchased two containers of aquatic milkweed, which had many more branches and foliage than my originals, and should be enough for all the babies.
Today, when trying to decide where to plant my aquatic milkweeds, I noticed that I was only down to 5 caterpillars now, so have decided to NOT plant the aquatics, but instead leave them in their containers, gently transfer the 5 babies to them, and leave the containers on my screened front porch, free from predation. This decision led me to your post… however, you mention starting the caterpillars on the potted plants, and then moving them to an indoor cage…
My question is: Is there any problem with just leaving them on the original potted plants on the porch? Have you tried just doing this before? I’d rather just be able to leave them be. I don’t mind if they tear up the plants. Just want to give them the best chance. Thanks for any advice and feedback.
Hi Alison, congrats on taking up this exciting new hobby that also helps the monarch population! You can leave them on a potted plant in your porch but there is a chance some could crawl away before they are ready to pupate. The main reasons they probably would do this are overcrowding or if the milkweed leaves aren’t healthy. I raise ours in a 3-season porch inside a cage and that has worked well. If you are interested in knowing more details about my raising process, I just republished my raising guide this month and you might find it helpful. Good luck with your caterpillars!
Monarch Raising Guide Info
Hi Tony,
I was reading your article on how to keep baby caterpillars safe and secure, when I ran across your tip to keep an eye out for caterpillars hanging by a thread after spraying your plants.
This was our first real successful year at raising caterpillars, but we did lose a small black swallowtail caterpillar when we found him dangling from a thread. Later during the summer, I found a small monarch caterpillar struggling at the end of a thread. I wasn’t sure what to do, so I left him there for about 30 minutes. He never was able to get back up to the leaf, so I decided to “save him” by pulling the entire plant up (it was a small volunteer), then cutting the leaf off the plant and putting it onto the paper towel.
It seemed like he was permanently stuck to the leaf? I continued to cut the leaf away until only a small portion of the leaf remained attached to him. Again, he seemed to be stuck to the leaf. I debated whether to leave the leaf stuck to him and see if he could lose it when he shed his skin, or should I try to operate and remove the leaf. By accident, since he was so small, I ended up removing the leaf. I gave the caterpillar a fresh milkweed leaf and left him on the piece of paper towel. He played dead the rest of the night, but in the morning, we found him on the milkweed. After that, he seemed to be fine, and eventually grew into a beautiful butterfly.
The question is, did I do the right thing? Would he have been able to get himself free off the thread? What is the right thing to do when you find a caterpillar hanging at the end of a thread?
Thanks.
Hi Brian, I would typically let them climb up themselves. If the cat seemed to be having an issue, I would take the thread between my thumb/forefinger and remove it with the caterpillar attached, then lower it on to a leaf.
Hello Tony,
I sent some comments in the above. I’ve done this previously and not heard back from you. Please, if possible, answer my questions in this post 06 Oct 2013. Thank you. I’ve learned some things I needed to know about tiny cats in reading some of these stories from your fans. That’s helpful.
I presume that most have a blog or website? I clicked on ‘follow’,..
Hi Sheri,
I always try to reply to comments. Most of the time facebook sends notifications but every once in a while I miss them. I will be looking into this in the offseason…may switch to just wordpress comments on the site. I answered your question above…