How to rear a caterpillar

Don’t forget to Register first!

This is so you can officially be part of The Caterpillar Conundrum team, and we can send you an evaluation of this project. Completing the evaluation survey is optional, however it will greatly assist The Caterpillar Conundrum team to improve the project  for the future. Please register and complete the survey that will be emailed to you before reading any educational materials on this website.

Step 1: Make a home for your caterpillar!

Find a large jar or other container. Clear containers work best, so you can see what’s happening inside. Wash your container, rinsing out any detergent residue. Put some dirt or sand at the bottom of your container – this will help keep the humidity stable for your caterpillar. Find some really fine flyscreen (if you do happen to have parasitoids emerge, they are really tiny and we don’t want them to escape!) or poke some holes in a piece of baking paper with a pin. Use an elastic band or hair tie to hold the flyscreen or baking paper over the top of the container.

Our caterpillar home. It still needs some more leaves so the caterpillar has lots to eat.
Our caterpillar home. It still needs some more leaves so the caterpillar has lots to eat.

Step 2: Find your caterpillar!

Caterpillars come in all colours and sizes. Look for plants in your backyard or local park that look like they’ve been nibbled on… it’s a good indicator that there are caterpillars around! Some caterpillars are more active at night, when there is less chance of them being eaten by birds. Collecting in National Parks or Conservation Reserves is not permitted without a permit.

For this project we are particularly interested in caterpillars that live on native Australian plants like gum trees or native shrubs, but you are welcome to try rearing any species of caterpillar that you can find. If you find a caterpillar not on a plant (for example walking along your porch) it’s not a good idea to collect them unless you are sure you know what plant they like to eat. Caterpillars are very fussy eaters!

Moth caterpillar image by Ken Walker, BowerBird. Image licence: Creative Commons Attribution Non-Commercial Share-Alike.

Step 3: Catch your caterpillar!

Don’t touch caterpillars with your bare skin. Caterpillars can irritate our skin, or we can easily hurt them (or the parasitoids inside them). Use a leaf or twig to transport your caterpillar to their new home. Put some of the plant you found it on inside the jar too – caterpillars are very hungry!

Step 4: Take a picture of your caterpillar and upload the picture to BowerBird! 

Click here to find out how to upload your photo to BowerBird

Step 5: Look after your new friend

You will need to replace the plant every few days as it dries out or gets eaten, so make sure you can access more. Caterpillars can be very picky eaters, so it’s important you remember which plant you found it on. You may also need to clean out the bottom of the jar because caterpillars eat a lot… which means caterpillars poo a lot!

Step 6: Caterpillar Cocoon

If your caterpillar forms a cocoon, you  need to be patient and check it every day to see if a butterfly or moth has emerged. Make sure there are some twigs or stems in the container for the new butterfly to hold on to when drying its new wings.

Caterpillars can form cocoons of many different types. This is a moth in the family Anthelidae. Image by Suzanne Jones, BowerBird. Image licence: Creative Commons Attribution Non-Commercial Share-Alike.

Step 7: Add a picture of your cocoon to your BowerBird sighting!

Click here to find out how to add another photo to your BowerBird sighting

Step 8: Wait patiently for your adult butterfly or moth to emerge

Caterpillars can remain inside their cocoons for a long time. It may be days, weeks, or even months before it emerges as a adult butterfly or moth. Be patient, don’t forget about it, and don’t lose hope! You can occasionally spray your cocoon with a mist of water to stop it drying out – but not too often, or it might grow mould.

Whilst you are waiting for your butterfly or moth to emerge from the cocoon, why not take part in some different BowerBird Projects? Or head over to our friends at The Discovery Circle and check out what they’re up to.

Step 9: When your adult butterfly emerges, take a picture and add the pictures of your adult to your BowerBird sighting!

Click here to find out how to add another photo to your BowerBird sighting

Butterflies will die quickly if left in a jar for too long, so once your adult emerges and you have taken some photos, release your transformed butterfly or moth into the same location you collected the caterpillar.

Snap a picture of your butterfly or moth before releasing it! Image by Ken Walker, BowerBird. Licence: Creative Commons Attribution Non-Commercial Share-Alike

Did you get a parasitoid instead of a butterfly?

Was your caterpillar infected with parasitoids? You may see the parasitoid larvae emerging, or you might just see the cocoons they make on the body of the dead caterpillar. If you do have some parasitoids, please collect them for us! Go here to find out how and where to send them.

Parasitoid wasp cocoons (on the remains of a caterpillar!) Photo by Martin Lagerwey on BowerBird. Licence: Creative Commons Attribution Non-Commercial Share-Alike.

My caterpillar died but there’s no parasitoids?

Some species of caterpillar can be difficult to rear. They might die of a fungal infection, or simply not be able to tolerate the change in environmental conditions. Don’t be disheartened. Try rearing a different species of caterpillar, making sure you wash the container out well before making a new home.