White-marked Tussock Moth

Two or more generations occur per year in eastern North America. They overwinter in the egg stage.

Eggs. Eggs are laid in a single mass over the cocoon of the female, and covered in a froth. Up to 300 eggs are laid at a time.

Larvae. The larvae are brightly colored, with tufts of hair-like setae. The head is bright red and the body has yellow or white stripes, with a black stripe along the middle of the back. Bright red defensive glands are seen on the hind end of the back. Four white toothbrush-like tufts stand out from the back, and a gray-brown hair pencil is at the hind end. The four white tufts on the larva's back may mimic the cocoons of parasitic wasps. Touching the hairs sets off an allergic reaction in many humans. Young larvae skeletonize the surface of the leaf, while older larvae eat everything except the larger veins. They grow to about 35 mm long.

Pupae. The caterpillars spin a grayish cocoon in bark crevices and incorporate setae in it. The moths emerge after two weeks.

Adults. The females have reduced wings and do not leave the vicinity of the cocoon. The males are gray with wavy black lines and a white spot on the forewings (the vapourer, Orgyia antiqua, is similar but is a rusty color.) The antennae are very feathery. Moths are found from June to October.

The genus name Orgyia is from the ancient Greek word ὄργυια, órgyia - 'outstretched arms'. So named because, when at rest, the moth stretches forward its forelegs like arms.