Whatever is a bag worm, do I hear you enquire? Indeed, I didn't know myself (despite having often seen them ) until quite recently when I discovered one of these interesting creatures dragging its home laboriously behind itself across our gravelly path. Fascinated, I watched its action as it ventured, half out of its cocoon, to grab the next couple of stones with its strong front legs, and then with the rest of its body pull its twig-decorated shelter behind it.
Saunders Case Moths (Metura elongatus) for that is their real name, spend most of their lives in these cleverly constructed cocoons. Even mating takes place (with difficulty) inside the cocoon.
The caterpillars can 'extend' their homes as they grow bigger themselves, by adding twigs woven in with their own silk, an onerous task. They move around by using three pairs of legs to pull themselves and their cocoon along. It's a very slow process. When they are ready to pupate, they attach themselves to a handy tree or post by silk threads, as shown in my first photo.
The female, who lives all her life in her cocoon ( no emancipation in this species) lays many eggs and dies within the case. She doesn’t develop wings.
The male moths, however, emerge from their cocoons in orange and black suits complete with wings, ready to search for a mate and begin the cycle all over again.
Until recently, a metal power pole on a roundabout in our town hosted scores of these case moths or bagworms. It seems they were very appreciative of the plants growing below, which rapidly showed signs of ill-health thanks to the caterpillars’ ministrations. After the moths departed, the cases hung and swayed in the breezes, slowly disintegrating over time, their occupants long gone.