Eggs are fuzzy in texture, and a cream-brown colour, approximately 2 to 3 centimetres wide. They are commonly found in tree bark crevices, as well as on vehicles, garbage cans, house brick siding and even outdoor furniture. The insect spends the Winter in the egg stage and then hatches the following Spring.
Caterpillars hatch end of April to early May. Caterpillars will be very small at first and will grow to approximately 2.5 centimetres in length. During the day, they will begin moving down the tree to hide from the hot sun and will climb back up late afternoon to feed on tree leaves at night. Caterpillars are dark in colour, with noticeable red dots along their back. The caterpillars will be covered in dark hairs. The caterpillar stage will last for approximately 40 days, before pupating.
Late June to early July, the caterpillar will begin to seek shelter to pupate. This stage will last for approximately 10 to 14 days. The caterpillar will form a dark brown cocoon-like structure, in which it will undergo transformation into the adult moth.
Moths are light brown to white in colour. They do not feed on tree leaves in this stage. Instead they will have 2 weeks to mate and reproduce before they die. Each female moth will lay between 500 to 1,000 eggs. The female cannot fly and tends to stay on the tree that she pupated on. Only males can fly.