Insects are truly amazing - but then again I would say that, I'm an entomology geek! Lepidoptera (buttterflies and moths) are among my favourite groups and yesterday on Phase 2, volunteers Rob Werran, Nick Shimwell and I were treated to a fabulous view of a burnet moth caterpillar in the process of spinning a cocoon.
Lepidoptera have a four stage lifecycle - egg, larva, pupa, imago (adult), in common with other insect groups such as the Coleoptera (beetles) and Diptera (true flies). Some insects go through a three stage lifecycle, comprising egg, nymph (the immature stage) and imago. Orthoptera (grasshoppers, crickets) and Hemiptera (true bugs) do this and the immature stage of the insect resembles the imago. However in four stage insects, the larval stage has a completely different body form to the imago, hence the marvel of metamorphosis!
The burnet moth in the photo below, once ready in it's pupa, will go through a complete body breakdown and re-build! This process is called histolysis and involves special cells withtin the body of the larva that initiate this process. Once complete, the imago insect emerges. It shouldn't be long now before we are seeing the adult burnet moths on the wing, so look out for their fast whirring flight and striking red and black colouration.
Burnet moth spinning a cocoon. Photo courtesy of Rob Werran.