I WANT TO BREAK FREE: BAGWORM

Rare moth caterpillars their camouflaged that escape cases once they've found a mate

- Nick Baker

HALFWAY UP A WOODY HEATHER STEM, I spied what appeared to be a caddisfly case. Nowhere near a pond, my suspicions were roused as this was too big a case to belong to a land caddis. I placed it on a stone H and waited.

A few minutes later, a small black head peeked out of the open end of the tube. It belonged to a caterpillar. It turns out that I had bagged a bagworm, an insect with a very interesting and surprising life-cycle, particularly given its uninspiring name.

The dusky sweep (Acanthopsyche atra) is one of 20 species of micro-moth that belong to the Psychidae family, or bagworms. These creatures, as their name implies, live for at least part of their life in a 'bag' or case.

It's very much like the case of a caddisfly larva: pieces of plant material - usually lichen, bark fragments, stems or seeds are sewn together to form a protective shroud in which the vulnerable caterpillar lives.