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Catch a Caterpillar!
Do you want to be a citizen scientist, and help researchers
learn about the world we live in? Be part of The Caterpillar
Conundrum project, and help scientists learn about caterpillars
and their parasitoids!
Contents:
Background information: Page 2
About the project: Page 3
How to participate: Page 4
Worksheet: Page 9
Student Certificate: Page 10
You can find out more about the project at
www.TheCaterpillarConudrum.org, including pages on ‘what happens in
the lab’, and curriculum links for teachers.
Like us on Facebook! www.facebook.com/TheCaterpillarConundrum
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Background information
What’s a parasitoid?
Parasitoids are animals that live on or in other animals, and feed off them to survive. They are
parasites, like the head lice you might have been infected with in primary school. A parasite normally
doesn’t kill their host (the animal they’re living on) but a parasitoid does. The parasitoids we are
studying are insects like flies and wasps that lay their eggs in caterpillars.
A parasite is a living thing that must live on or in another living thing to survive. Some parasites you
may have encountered before are animals like head lice, which live on human scalps and feed on
blood. Have you ever been bitten by a leech? They’re parasites too! Mites and gut worms are other
common parasites of humans, and there are even plants that are parasites of other plants! Parasites
tend to keep their host (the living thing they are feeding from) alive for a long time.
A parasitoid, unlike a parasite, often kills their host as part of their lifecycle. When a parasitoid wasp
lays her eggs inside the host, the eggs hatch and the baby wasps (larvae) eat the host slowly from
the inside, being careful not to kill the host too quickly. When they have grown enough, the larvae
eat their way out of the host, which normally kills it, and form cocoons on the body of the host. The
larvae undergo metamorphosis in their cocoon and emerge as adult wasps.
An endoparasitoid lives inside their host, whilst an ectoparasitoid lives on the outside of their host,
such as on the hair or skin. The particular group of wasps we are studying are endoparasitoids that
live inside caterpillars of butterflies or moths. They are important as natural enemies of caterpillars,
keeping their populations in balance, and also as biological control agents. Biological control agents
are animals (or other organisms like bacteria, viruses or plants) that are used by farmers to reduce
pest numbers. Some parasitoid wasps are used in crops to keep pest caterpillars from building up
large population numbers where they can badly damage the plants.
What’s a citizen scientist?
A citizen scientist is anyone who wants to be part of real science and help professional
researchers discover new things.
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About the project
What is the Caterpillar Conundrum project?
We are asking volunteers to rear caterpillars that they find in their backyard or local park, and we
will then upload the photos and data to a BowerBird Project. A small number of these caterpillars
will have parasitoids inside them, which will form cocoons on the body of the caterpillar and emerge
as wasps or flies. If this happens, we’ll ask the volunteer to send in their parasitoids and dead
caterpillar so we can sequence the DNA. The DNA will help us learn about the relationships between
parasitoids and their hosts.
Why do we need the help of citizen scientists?
This is real science, and we really do need your help! Rearing caterpillars takes time, and only a small
number get infected by parasitoids. To collect enough information, we need to rear hundreds of
caterpillars… a big job for one PhD student! The more information we collect, the better we can
understand how the caterpillars and parasitoids interact.
Why do we want to know about caterpillars and parasitoids?
Well if you like hot chips, or apples and pears, this information is important to you! Potato crops and
orchards are just a couple of examples of farming crops that battle with caterpillars eating their
plants on a daily basis. Whilst these caterpillars have an important place in nature, we don’t want
them taking over our crops. Parasitoids are an important part of solving this problem. By releasing
parasitoids into their crops to reduce caterpillar numbers, farmers don’t need to spray as many
pesticides, which kill beneficial insects too. The parasitoids are what we call biological control
agents… like the secret agents of the farming world.
Before we can know what parasitoids might be useful, however, we need to know how they are
related to each other and what caterpillars they infect – that’s where you come in!
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How to participate
Step 1: Find and rear a caterpillar
Step 2: Take pictures and fill out the worksheet (page: 9)
Step 3: Release your butterfly or moth
Step 4: If you find parasitoids, send them to us!
Step 5: Tell your teacher or parent you’ve completed the project, give them your photos and
worksheet and they’ll send us the information to share with the project!
Teachers and parents: Please email worksheets and associated photographs to
[email protected] so that they can be uploaded to the citizen science project, or
upload them yourselves using the instructions at
http://thecaterpillarconundrum.org/participate/how-to-upload-your-data/
Step 1: Find and rear a caterpillar
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.
This is our caterpillar home. It still needs some more leaves so the
caterpillar has lots to eat.
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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, 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:
1) Take a picture of your caterpillar and save it somewhere safe.
2) Fill out the first section of the worksheet
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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:
1) Take a picture of your cocoon
2) Fill out the second part of the worksheet
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 an adult butterfly or moth. Be patient, don’t forget about it, and don’t lose
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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 citizen science projects?
Step 9: When your adult butterfly emerges:
1) Take a picture of your butterfly or moth
2) Fill out the third part of the worksheet
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! Ask your parents or coordinator to give us a call on (08) 8313
8246 and we’ll give you some more information and send you out some containers and a reply paid
envelope to send them back to us!
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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 cope with 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.
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Name:
Don’t forget to take a photograph of your caterpillar!
Don’t forget to take a photograph of the cocoon!
Don’t forget to take a photograph of the butterfly or moth!
Part one: fill out when you find a caterpillar What date did you find your caterpillar?
What is the postcode where you found your caterpillar?
Can you describe where you found your caterpillar? What sort of plant was it on? (For example, did you find it on a mint plant, or a gum tree?)
Can you describe your caterpillar? You might want to talk about the colour and shape. Does it have spines or patterns? How big is it? (You might want to use a ruler to measure it).
Part two: fill out when your caterpillar makes a cocoon What date did your caterpillar make a cocoon?
Can you describe the cocoon? What does it look like?
Part three: fill out when your butterfly or moth comes out the cocoon What date did the butterfly or moth come out?
Can you describe it? What does it look like?