An activity for all ages.
If you have loads of caterpillars on the cabbages or broccoli in your garden, you can bet they are either from large or small white butterflies. Be happy! You can watch their life cycle very easily with a few of them and then keep an eye out for more eggs. Remove the part of the leaf with eggs if you don’t want them all to hatch and munch their way through your veg.
- You’ll need a tank to keep them in – you can find one in a pet shop that will have ventilation and an opening to access them.
- Watch out for the butterflies around the plants, you might even be able to film them laying their eggs. You could note the date when each stage happens (egg, small caterpillar, bigger caterpillar, pupa formation, adult emerging.
- Place a few of the caterpillars in the tank with some of their food source. (You might want to leave the caterpillars on the plants outside so they have shed their skin a few times and are less small and delicate before you put them in the tank).
- Keep changing the leaves as they will dry out. There’ll be a lot of caterpillar poop!
- Eventually the caterpillars will climb up to the top of the tank and start spinning their pupa. How can you tell they are doing this?Wait! How long it takes for the adult to emerge depends a lot on the temperature where they are kept. It may be best to keep the tank in cool dark place over the winter, so the new adults come out in the spring. They tend to come out of the pupa overnight, so you have to keep an eye on them because soon after they emerge they will then need to be let out of the tank so they can feed and drink outdoors.
Could you take a picture of each stage? Or a video of some bits like the caterpillars feeding and the making of the pupa? My pictures are of the large white butterfly life cycle, but the small white butterfly has green caterpillars and different shaped eggs.