Enormous (10-12cm) grey and white caterpillar with tufts of reddish bristles, which are left sticking out of the long, tapered cocoon. Adult moth has a wingspan of up to 16cm, is patterned in wavy bands of grey and brown.
Eucalypt forests and woodlands of south-eastern mainland Australia-Victoria, ACT, eastern NSW, south-eastern Queensland. Often found in suburban areas. Native fauna.
Caterpillars feed on eucalypt leaves from winter through to summer. Mature caterpillars often come down from trees in January and February to wander, crossing roads and entering gardens in search of a place to pupate. Cocoons appear on tree trunks, walls and even in letterboxes, are also covered in spines, forced out through the silk by the caterpillar. The moths emerge on autumn nights and are rarely seen except when attracted to lights.
Caterpillars consume quantities of gum leaves but are never abundant enough to be significant pests. More important medically-spines of caterpillar and cocoon break off when touched and penetrate skin, causing irritation and occasionally a toxic reaction.
Control neither practical nor necessary.
Don't touch caterpillar or cocoon.
Images show cocoon of the white-stemmed gum moth (left) and close up showing irritating hairs (right) embeded in the cocoon.