quality:corruption, information:highlighting, structural:summarization
Larvae

Larvae (caterpillars) emerge from egg masses in the spring. Most larvae hatch within a week, but can take as long as a month. The new larvae remain on or near the egg cluster if they hatch in rainy weather or if the temperature is below 7 °C (45 °F). The larvae will disperse even if there is enough foliage for growth, hanging from silk threads and waiting for the wind to send them aloft. The larvae are about 3 millimetres (15 ⁄ 128 in) long when they first hatch and will grow to 50 or 90 millimetres (1 + 15 ⁄ 16 or 3 + 9 ⁄ 16 in).

The larva will first feed on the leaf hairs and then move onto the leaf epidermis. Feeding occurs in the daytime, primarily in the morning and late afternoon. As the larva grow, the feeding becomes a nocturnal activity. When not eating, the larva will remain on the underside of the leaf and make a mat of silk for attachment.

To grow, the larva must molt. Larvae are characterized by the term instar, which refers to the number of times a larva has molted; a first-instar larva has not yet molted, a second instar has molted once, a third instar twice, etc. Males typically are five instars and females are six instars. When the larvae reach the fourth instar, they become nocturnal feeders, and will return to their resting places at dawn, hiding under flaps of bark, in crevices, or under branches - any place that provides protection.

Newly hatched larvae are black with long, hair-like setae. Older larvae have five pairs of raised blue spots and six pairs of raised brick-red spots along their backs, and a sprinkling of setae. As the larval stage comes to an end they cease feeding and surround themselves in a silken net.