Image: Ribbed case moth

Ribbed case moth

Ribbed case moth

Allan Ryan
© Allan Ryan
Parkes, NSW
Date taken:
29 May 2002


Case moths, bag moths or bagworms are names given to a group of moths whose caterpillars make portable homes from silk, usually attaching plant material, detritus or sand grains to the outside. Caterpillars of each species build quite distinctive cases, although there can be considerable variation within a single species, especially in those that feed on a wide variety of different plants. This species is found from southern Queensland to Victoria and feeds on eucalyptus and brush boxes. The cases of this species grows to about 4cm.

Case moths spend most of their lives as caterpillars, the larval stage, which may last for up to 1 or 2 years in some species. Once constructed, the caterpillars never leave their cases. The head and thorax of the caterpillars are quite heavily armoured and they have 3 strong pairs of legs on the thorax with which they move around, dragging the case behind them. The case has two openings, a larger ‘mouth’ through which the caterpillar protrudes its head and thorax to feed and move, and smaller hole at the other end through which the droppings are ejected. Many species of case moth caterpillars are plant feeders; others feed on lichens; while some live within the nests of ants and are thought to be scavengers.

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