Caterpillars as Pets

Is there anything more fascinating to kids than those brown fuzzy caterpillars that plague our gardens during winter? If your little ones are anything like mine, finding these little “Woolly Bears” can be the highlight of their day.

Last winter we decided to collect some and raise them to see what they turned into. We often collect caterpillars from the garden to watch them go through the process of pupating and emerging as either moths or butterflies. We call them “Surprise Bugs” because we don’t always know what they will turn into! It’s actually very easy to do and makes for an interesting school project or a temporary new pet.

Woolly Bear caterpillars can be found on many common garden plants in Adelaide, such as Geraniums, Aeoniums and Dandelions. If you have Swan Bush or Milkweed in your garden you may find stripey Monarch Caterpillars that hatch into bright orange and black butterflies. Another beautiful butterfly that is easy to rear is the Dainty Swallowtail, whose caterpillars can be found on citrus trees. They make a stunningly camouflaged chrysalis that mimics the markings of the citrus tree stems. Granny Moth caterpillars can be found on Acacia plants and be sure to keep an eye out for Looper caterpillars on Eucalyptus and Bottlebrush, they inch along with an almost comical gait.

To raise caterpillars as pets you’ll need a mesh or glass enclosure with plenty of ventilation. I have several cheap pop-up mesh ones that I bought online, but a large Tupperware container with a piece of stocking or mesh to replace the lid is an easy option.

Some things to remember:

  • Do a bit of research. You want to find out how the caterpillar will pupate. Butterflies often form a chrysalis on the stem or leaf of the plant, but Woolly Bears actually drop to the ground and bury themselves, forming a cocoon under the soil. It is important to have a 5cm layer of dirt or ideally coco-peat at the bottom of the enclosure for the Woolly Bears so they can pupate.
  • Make sure you pick some of the plant you collect the caterpillars from so they have the right food to eat. Some caterpillars eat a lot, so you may need to replace the greenery. Placing the stalk of a cutting in a vase will keep it fresh for longer. But be careful, caterpillars are not very smart and can crawl into the water and drown. Best to cover the opening of the vase with some scrunched up aluminium foil or gladwrap.
  • Ensure you have the right food for the adult moths or butterflies such as nectar-producing flowers. It is best to give the newly emerged adults a good feed before releasing them, although we have found that our Woolly Bear moths are not very interested in food until after we have released them.
  • Be patient! Our Woolly Bears did not emerge until about 6 to 8 months after they buried themselves. Butterflies tend to pupate in a much shorter time frame.
  • Websites such as sabutterflies.org.au or reputable Australian entomology groups on Facebook can be a great source of information, from species identification to ensure you have the right conditions for your bugs.
  • When butterflies and moths emerge their wings will be small, damp and crumpled. Watching them unfurl is a wonderous thing but be careful not to touch them until they have fully dried out as they easily damage.
  • Butterflies and moths can be easily handled by coaxing them onto your hand, a leaf or stem. Be especially careful with moth wings, as the tiny “dusty” scales can come off easily.
  • Sometimes nature takes its course and the caterpillars we collect don’t survive the whole life cycle, despite all the right nurturing conditions. Be prepared to have that conversation with young children.

So, what did the Woolly Bears turn into? Glatigny’s Tiger Moths (Spilosoma glatignyi), beautiful black and white moths with adorable fuzzy faces and bright orange striped bodies. Well worth the wait! I wish you the best of luck with your own “Surprise Bugs”, we’d love to see some photos of what you find and what they turn into.

Fun Fact: Caterpillars have 6 legs, like all insects. Their true legs are located on their thorax, nearest the head. The rest of the “legs” are actually prolegs, an adaptation to help them get around during the larval stage.

Written by Tracy McNally, Animal Caretaker

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