THE other day we noticed a green caterpillar on one of the tomato plants. Having plucked it off ready to deposit elsewhere, we realised that the tomato plant was nearly dead anyway so the caterpillar might as well enjoy the last few leaves. So we put it back. Imagine our surprise when the next day we found it tucked cosily in a cocoon! In fact there were two of them! Two days later the plant was indeed dead, as was apparently the second pupa. But the first pupa still wiggled when gently prodded, and one part had turned brown inside its opaque, silky home.
On my return from a trip four days later, Emma greeted me with: "Mama! The most amazing thing happened!" It seemed that the pupa had transformed into a moth, which Emma had discovered drying its wings next to the empty cocoon. It had flown away by the time I got home, so we didn't get to photograph or identify the moth or butterfly, but it could have been a diamondback moth.
Pupa, Chrysalis or Cocoon?
A pupa is an insect undergoing transformation. If it is a butterfly pupa, it is called a chrysalis and is surrounded by a hard casing. Moth pupas most often change inside a cocoon of spun silk, though some species burrow into the ground. Pupas of other insects change inside the exoskeleton of their final larval stage, or in a nest or shell.