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I often get questions about how to raise caterpillars. One of my first jobs during college was raising caterpillars, which lead to similar jobs throughout the years. Why raise a caterpillar? Not only does successfully taking care of another living thing lead to insights into its biology and behavior, but also when a beautiful butterfly or moth emerges, it is an amazing experience.

A few weeks ago I wrote a post about white-lined sphinx moth caterpillars.

whiteline caterpillar

In the update I mentioned that I had placed a caterpillar in a terrarium with moist potting soil (about five inches deep). The caterpillar immediately disappeared, but I knew where it had gone. Large moth caterpillars, like white-lined sphinx moth caterpillars or tomato hornworms, dig into the soil before pupating. Their pupa looks like a dark reddish-brown cigar. Saturday I found the moth sitting on the cloth I had used to cover the terrarium. It had successfully emerged.

Here it is.

whitelined sphinx mothwhitelined sphinx moth

Because white-lined sphinx moths are big and active, they need a lot of nectar to keep them going. After taking a few pictures, I immediately let it go. Here’s a link with some amazing pictures of white-lined sphinx moths. This entire website is full of great information and photographs.

What do you need to raise caterpillars? It does depend on what kind, but here are some general guidelines.

1. Unless you are using a kit that supplies special food, you will need large quantities of fresh plants. And not just any plant, most caterpillars will only take one or a few kinds of plants as food. Once a tiny larva has started eating one kind of plant, they often will refuse to take anything else, even if other members of its species will. A good rule of thumb is only bring home caterpillars that you are absolutely sure you know what they eat, and you have lots of those plants available to feed them. Edit: What white-lined sphinx moth caterpillars eat.

2. Provide a clean, safe container covered with screen or cloth to allow for air circulation. It is best to keep the container outside in as natural conditions as possible. Insect life cycles are extremely sensitive to light and temperature. If you bring the critter inside where it is cool and dark, it may emerge days or even weeks after wild members of its kind and may miss critical windows of opportunity to perform necessary behaviors like mate or migrate.

3. Keep only one or a few in a container. Crowding insects into small containers greatly increases the chances for disease. Insects can get viruses, bacteria and fungi, which can make them sick, just like those things can make humans sick.

Scientists have suggested that monarch butterflies may migrate because of a parasitic infection. This parasite (a protozoan) causes the butterfly to be weak but not die. By going on long migrations, the sick individuals are left behind. When we handle monarchs, we risk spreading the disease even more. Let me know if you’d like more information about this.

4. Provide sticks for butterfly caterpillars to climb on when they are about to make their chrysalises. Moth caterpillars will need plenty of moist soil to dig into. Other caterpillars may like to have different substrates to pupate in, like cloth or egg cartons.

5. Insects are also sensitive to humidity, especially when they are molting. It can be tricky, but try to keep the humidity up without getting the container too moist. Too much humidity can cause things to get moldy.

I hope these guidelines doesn’t sound too negative. Having a lot of experience, I have a better idea of all the things that can go wrong and I wanted you to avoid the problems. And oh yes  here's one more:  don't leave the lid off the container once the caterpillars have pupated. My son did this, and we had cabbage-looper moths all over the house. (It was actually a hoot!)

One great way to raise caterpillars is to plant butterfly and moth plants in a butterfly garden. (Check out an earlier post on butterfly gardening.) Then the caterpillars do all the work themselves.

Also, don't forget to take a look at some of the butterfly and caterpillars books for children.

And finally, my friend Debbie called again. Her passion vine plants now have gulf fritillary caterpillars on them (see last week’s post for details).
gulf fritillary caterpillar

This week my friend Debbie called and invited me to visit her butterfly garden. Sure enough, when I arrived there were several species of butterflies flitting throughout her yard. By far the most common were the bright orange and silvery white gulf fritillary butterflies. I also saw numerous skippers and a few giant swallowtails, as well as a yellow sulphur butterfly.

It was hard to get the active gulf fritillary butterflies to sit still long enough to get a photo. The adults were searching her yard for the numerous passion vine plants she had planted. The adults lay eggs on the plant and the caterpillars use it for food. Can you guess what happened to this one?

gulf fritillary

Here’s an adult apparently laying eggs on a piece of passion vine. Note the remnant of a chrysalis hanging to the left of the butterfly. Can you see the beautiful silvery-white patches on the undersides of the wings?

gulf fritillary

Debbie’s passion vines are in various stages. Some have no leaves left from all the caterpillars that have been feeding on them in the past. If you are going to have brilliant, vibrant butterflies, you’ll have to accept that your plants may look a bit raggedy. The vines are around an aloe plant in a pot.

passion vines

She has a couple of different passion vines, with different shaped leaves. Here is one that still has leaves.

passion vine leaf

Here’s another with an empty chrysalis.

fritillary chrysalis

The passion vines have gorgeous, very unusual flowers. I couldn’t find flowers this week, but here is one I shot at the National Botanical Garden a few months ago.

passion vine flower

Here is a link for passion vine flower photos of several different species.

I did find a fruit.

passion vine ruit

Debbie opened one and showed me the unusual seeds inside. Cool!

passion vine seed

Here is a cute skipper that was more willing to pose for me than the fritillaries. The skipper caterpillars feed on various grasses and they are quite common. Sometimes they are mistaken for moths because of their drab brown color.

skipper butterfly

This experience made me realize how very rewarding butterfly gardening can be. We were able to see and talk about so much in just a short period of time. With a few well-chosen plants, some sun, water and patience, Debbie has created a lively and enriching environment.

Debbie, thanks for sharing.

For those interested in butterfly gardening and caterpillars, here are a few more children’s books to consider.

2015 Edit:  For our most complete and up-to-date list of butterfly books for kids, visit  Science Books for Kids website.

moth-and-butterfly-books-for-children-list

Nonfiction

Nic Bishop Butterflies and Moths by Nic Bishop just came out and it is fabulous!

The butterfly book : a kid's guide to attracting, raising, and keeping butterflies by Kersten Hamilton.

This butterfly book for older children is full of scientific information and suggestions for activities, such as making a butterfly net. It starts out with a “getting to know” section that covers much of the complex vocabulary children will need to read this and other books about butterflies. Then the author covers many aspects of raising and keeping butterflies, as well as butterfly behavior and biology. A butterfly guide on the edges of each page has extensive photographs and accurate illustrations of common butterflies, and includes a map of where they are found. The resource guide and “glossarized index” at the end help children find out more. If you are interested in raising butterflies or butterfly gardening, this book is an excellent resource.

It's a butterfly's life by Irene Kelly.

This nonfiction book has many lovely illustrations. If you are looking for a book for a child to read, be aware that the font looks like hand lettering and the sentences wave up and down across the page, almost like the pattern of a butterfly flying. This looks lovely, but may be hard for a beginning reader to read. It has many interesting facts, and covers the butterfly life cycle in detail.

Creepy, crawly caterpillars by Margery Facklam and illustrated by Paul Facklam.

All the terms used throughout the book are defined in the text in the first two pages. The second page of this book has an absolutely amazing illustration of a caterpillar with all its parts labeled clearly and accurately. The rest of the book is two-page spreads of specific common and interesting caterpillars, for example the woolly bear and the cecropia moth caterpillar. Most of the caterpillars chosen are actually moth caterpillars, rather than butterfly caterpillars, but it is still fascinating to learn about them. This book has a glossary.

Face to face with caterpillars by Darlyne A. Murawski.

The author is a photographer who talks about how she got some of her stunning photographs next to the actual results. She starts out with the story of a caterpillar that eats ants and how she photographed the caterpillar through glass. This and some other parts of the book feels as if the photographs drove the text, rather than vice versa. There is a great deal of information on caterpillars, however, to accompany the wonderful, one-of-a-kind photographs. The end contains a glossary: a “find out more” section with articles, books and websites; an index to help children search the text; and a sidebar of research and photographic notes.

Fiction

The girl who loved caterpillars : a twelfth-century tale from Japan adapted by Jean Merrill and illustrated by Floyd Cooper.

It is hard not to love a book that is so beautifully written and illustrated. The overall tale is of a lovely young Japanese girl who defies the traditions of her time. She prefers caterpillars and centipedes to butterflies, and collects and raises them. This story is incredibly complex, and even makes adults who read it think deeply about it. One issue is the fact that the story is probably only the first chapter of a much longer tale, but the rest has been lost. Some people may wonder why the author didn’t construct her own ending. Rather than detracting from the book however, for me it only made it more interesting.

There are more butterfly book reviews at the end of the white-lined sphinx moth post.