How to raise giant caterpillars

August 8, 2014 • 4:26 am

Reader Mark Sturtevant, who appeared previously with pictures of GIANT INSECTS, has some practical advice about how to raise them for fun (but not profit). If you have kids, this is a cool way to teach them about complex life cycles, and has the advantage that, at the end of it all, you set the insects free.  Here’s Mark’s advice; the only requirement is fresh leaves, which should be available if you’re synchronizing your hobby with nature:

 You may remember that I was raising a batch of cecropia larvae (Hyalophora cecropia) and documenting the process with pictures. These grow into one of the largest larvae in the U.S. (but not the largest by length) and later become our largest moth. Raising giant Saturniid moths is a hobby of mine, and now I am discovering that taking pictures makes it even more rewarding. The several pictures show the different growth stages that they have passed through so far. The pictures of the younger larvae were taken with an iPhone 5S with a cheap clip-on macro lens. The larger larvae were photographed with a Nikon Coolpix camera.

1. Newly hatched 1st instar larva with eggs, and mature 1st instar. Eggs are kept in small serving cups without food. Larvae are transferred to leaves of a chosen food plant. I am using the common garden lilac as their food source, although they will accept over a dozen species of common plants. Once they are started on a food plant, however, they will not accept a different species of plant.

1 Hatching and First Instar

2. 2nd , 3rd,  and early 4th instar larvae. One of the things I like about this species is that the larvae change their colors as they grow. I have no idea why they do this. [JAC: Readers? Do you know? I suspect spines are predator deterrent and that the caterpillars are toxic. The colors are probably “aposematic,” or warning colors to deter predators as well. But I have no explanation for the color change over time.] The spiny decorations may somewhat deter ants, and they might make them unpleasant for birds to swallow.

2 2nd 3rd 4th instar

3. Mature 4th instar larvae. By this time they are over 2 inches long. Next, they will molt to the final (5th) instar, and then get really REALLY big before spinning cocoons. Next year I should have a bunch of giant moths that look like cuddly plush toys.

3 Mature 4th instar

4. These pictures show how I feed my babies. The larger larvae stay on a bouquet of branches in a big plastic jar. The air holes have to be large so that condensation does not form.

4 Feeding

Eggs and pupae can be purchased through a breeder who lives in Canada. This hobby is easy and fun for adults, and kids go bonkers over these beautiful monsters.

Here’s a picture from the breeder’s website. Can there be a prettier hat? (Bonus points: identify the moths.)


Mark continues:

The ultimate species, in my opinion, are hickory horned devils. By length, these grow into the largest ‘pillars in the U.S. I raised a batch last year, and I have pictures to prove it. But I plan to raise both cecropias and hickory horned devils next year. I think the two should meet! It will be Mothzilla vs Mothasaurus rex!

 I’ve found a photo of a hickory horned devil caterpillar (below); it is large and fearsome. Now wouldn’t your kids like to bring up one of these?
“Hickory horned devil” is only the name of the caterpillar; the adult stage is called either the Royal Walnut Moth or the Regal Moth (Citheronia regalis). Here’s the lovely adult. If you raise these, you have to let them go within their natural range (mid-Atlantic and southern U.S. west to Texas).

41 thoughts on “How to raise giant caterpillars

  1. Cool! I am going to check out that site for raising them. I won’t be able to raise the really neat looking one in the pictures, but maybe luna moths which I haven’t seen here for years!

    1. Luna moths are a great species to start out with, as they grow very fast. One can generally get two generations a year. But if you have trees you probably could find several species that you could raise.

  2. That hat seems to have two cecropia moths (Hyaloptera cecropia), an io moth (Automeris io) and a luna moth (Actia luna). I’ve seen regal moths every once in a while, and they are giant and beautiful things.

  3. Terrific! I was hoping you’d share more, so THANKS!
    So what is the time frame from an egg to adult moth in this species (assuming all the conditions are optimal)?
    Also do you know if the breeder collects the eggs in the wild or has some sort of crazy in-door moth/butterfly garden where they copulate and lay eggs in a controlled environment. That’s a part of the process that seems the most difficult, esp. since he has so many different species.

  4. The eggs hatch in 2 weeks, but it can take longer. From newly hatched larvae, one can get mature larvae in about 2 1/2 months, so the whole affair pretty much covers the summer. If the time investment is a bind due to things like family vacations, I would recommend either having some friends watch them for a while, or you can try a fast growing species like Luna moths. Lunas go through 2 generations in one summer, so you can try an early or late generation.

    I raise my critters strictly indoors so that I can always see what is going on. The commercial breeder mentioned above, Bill Oehkle, raises different species outside on trees. He protects the larvae by keeping them in a large fabric sleeve. I think he also keeps outdoor cages for overwintering and emerging adults, and they mate in the cages. Overwintering indoors is also no problem (done in a refrigerator), and if you have a bunch of them you can mate the brothers and sisters once they come out in the Spring if you want.

    1. Tip on how to make a home-made sleeve for a tree branch: old sheer curtains sewn along three sides, slipped over branch, and tied with string at the proximal end.

  5. I can understand how some people find insects intriguing, interesting, or even beautiful. But try as I might, I just can’t overcome my disgust and disdain for the critters.

    Logically, I know many insects are beneficial and ecosystems would collapse without them. But my emotional side recoils from their alien nature. I don’t have a phobia of them, thankfully. I can handle them w/o freaking out. I just don’t like bugs. They move too quickly, crawl into crevices they don’t belong, and wear their bones on the outsides of their bodies, which is plain creepy.

    What’s the general consensus? Do most people here appreciate and enjoy insects? Or is it more of an academic appreciation undercut by a sense of “Hey, that’s kinda icky?”

    1. You can overcome some of that by raising these sorts of caterpillars. Having them on your hand feels alien at first but then you realize they cannot hurt you and you become fascinated things like how those tubular “legs” work, or how they poop. After a while the ick factor goes away and the exploratory or fascination factors kick in.

      But you have to try. A friend who has an irrational phobia of even small snakes said she simply was not even willing to try.

    2. I wouldn’t want to be an entomologist, or a subset of that disciple, but ever since I can remember, I’ve loved all arthropods. Tarantulas and Praying Mantis topped the list. I’m very allergic to honey bees, so stay away from them, but other than that, bring ’em on. Though a botfly maggot in the head like what Jerry had? You can count me out! Tropical insects can be dangerous, so that is a caveat for me.

    3. Another thing about the Cecropias is that the adults do not eat or drink and so you can say to yourself that they cannot hurt you either.

      Some insects still gross me out, like the deer ticks that constantly give me lyme disease (and cost me lots of healthcare dollars), or other disease-causing insects. But when you learn a little about the various kinds you can start seeing beauty in some of them, such as the emergence of the mayflies that was covered a few wks. ago here on this website. I went to an outdoor concert along the Miss. River many years ago on a nite the mayflies came out, and it was truly magical. They decorated our clothing with glistening bits of wing, and tens of thousands in front of the baseball lights that nite made it look like it was snowing. The blues guitarist on stage had his hat covered with them, and a few on his guitar. Talk about a unique experience! All harmless, and you could barely feel them. And of course they don’t bite or sting.

      Stuff like this might help you appreciate some insects more. Looking closely, and even taking up photography on your own might help. And doing these caterpillar raising experiences especially with children lets you become a possibly more open-minded child yourself again : )

      1. I should correct myself, and for other readers, that ticks are not technically insects. Jheez. I knew that.

    4. I am pretty biased in favor of all creepy crawlies, including the fast ones that zip up your legs and look for a crevice to hide in.
      But the various Saturniid caterpillars are the opposite of that sort. They move slowly, and are very reluctant to leave their plant. Getting one to crawl on you is not easy. But once in your hand, they feel kind of cozy. The thick prolegs on the abdomen feel like cool suction cups.

      1. Mark, I appreciate your perspective, but I think we have different definitions of “cozy.” 🙂 Of course, much of biology squicks me out, so it isn’t just bugs. I still find it weird that mammals feed their young excretions from modified sweat glands.

    5. I love bugs! I suspect, though, that this website attracts a higher proportion of bug-lovers than that of society as a whole.

      1. Yes. I agree Diane. I watch ten min. or so of the Jerry Springer show every once in a while just to remind myself of the variety of people in this world.

          1. Every time I see that phrase “I like bugs” I’m reminded I’ve seen it somewhere on TV. Finally clicked – in the TV series ‘Hercules’, Herc’s little buddy Iolaus is bound in spidersilk and comes face to face with the beautiful, vain and cruel spider-woman Arachne**, and the best he can manage is a nervous “I like bugs”.

            ** It’s a bit like that moment in Alien where Ripley comes face to face with the alien.

  6. “Once they are started on a food plant, however, they will not accept a different species of plant.”

    That’s interesting! It would be nice to know if that effects their growth. Does eating one type of plant turn on/off certain genes during development as opposed to eating another plant?

    1. I have never learned why they refuse all other possible plants once they start eating a particular species of host plant. This is very common with caterpillars, though. There are species that eat only one species of plant. This must be genetically programmed on the basis of their physiology and/or behavior. So perhaps the other species of caterpillars become genetically programmed later, as you suggest.
      The one time that I raised hickory horned devils, I decided to try some on walnut leaves and others on staghorn sumac leaves. These are both known host plants of this species. The larvae on walnut did very well, and grew quickly with low mortality. The ones on sumac, however, grew much more slowly and several had died. So the different host species are not necessarily equal.

      1. I have wondered the same thing, about cecropias. They did well for me on chokecherry in central IL

        I’ve wondered if ingesting the initial leaf species sets up a larval gut ecology that doesn’t take well to change. Given what scientists are learning about the human microbiome (in our mouths, in our guts, on our skin, etc.), it would not surprise me.

        1. That is a good idea. And as we know, our gut microbiome has widespread effects on several of our systems. I do not know about caterpillars on this, but probably someone has checked this out.

  7. The pictures are great, and it is fun to raise caterpillars. But please, check out any dealer carefully, and don’t release them! Transported animals can cause a number of problems for wild populations. The North American Butterfly Association has a good though incomplete list of the potential harms:

    All of the reasons apply to any invertebrate transport/release. In some states/counties, it’s illegal to release any animal, including insects, without a permit.

    Cherry picking a couple of reasons:

    They can carry new diseases to wild populations (commercial breeding operations often have disease problems, just as any livestock/nursery operation).

    They can interfere with ecological studies/surveys. Painted Ladies especially are the bane of people trying to study their migrations.

    A much better solution is to learn to spot your local caterpillars and eggs, and rear those. They teach the kids a lot more about your local habitats than purchased specimens, and they can be safely released. As a bonus, you may able to contribute to what’s known about what a larval species eats and the life cycle timing, and distribution. If you have something not easily identifiable, is a great resource.

    1. I am glad you wrote this so that people can read up on things a little and make informed decisions. That naba page seems pretty good.

      In my case I had found a wild cecropia cocoon in the autumn, by chance, and when it emerged in spring it was a female. I kept it in a screened cage (they do not eat or drink, their only purpose is to lay eggs) and a wild male flew in and mated. I put the mated female into a large brown paper bag where she laid her eggs, and then I could raise the larvae first indoors on cut chokecherry branches, and then outside on the same chokecherry tree in my backyard. I did this for three summers. The neighbor kids loved it.

      I do highly recommend starting with local, native stock if you are going to let any of them go or if there is a chance any will escape. Federal regulations can be lax or inadequate on all sorts of things and we should use our heads after doing a little research. This would also be good info to pass along to any children so that they get the full picture of animals not only be wonderful and fun, but also so they get a bigger picture of ecology and science.

    2. I agree with the advice about not releasing species from one population into a far-flung population. That this is done is a wide-spread practice, however, especially for the much larger business of butterflies like painted ladies.
      Although no disease has been introduced in lepidopterans this way, it is true that it could happen. So this is very good advice.

Leave a Reply