White-marked tussock moth

There are two or more generations a year in eastern North America (Wagner 2005). 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 (Wagner 2005). Up to 300 eggs are laid at a time.

Larvae
The larvae are brightly coloured, with tufts of hair-like setae. The head is bright red, the body has yellow or white stripes, with a black stripe along the middle of the back. There are bright red defensive glands on the hind end of the back. Four white toothbrush-like tufts stand out from the back, and there is a grey-brown hair pencil at the hind end. Touching the hairs will set off an allergic reaction in many humans (Wagner 2005). Young larvae skeletonize the surface of the leaf, while older larvae eat everything except the larger veins (Rose and Lindquist, 1982). They grow to about 35 mm.

Pupae
The caterpillars spin a grayish cocoon in bark crevices and incorporate setae in it (Rose and Lindquist, 1982). The moths emerge after 2 weeks.

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