Lepidoptera The Oak Eggar Moth – Bombyx Quercus
The ground colour of the caterpillar is black; but it is so closely covered with short yellowish brown hairs that the black is scarcely visible, excepting when the creature rolls itself up into a ring, which it does when alarmed. The spiracles are white, and there is a series of white spots down the middle of the back and along each side. It feeds on whitethorn (Cratagus oxyacantha), heather (Calluna, Erica), poplar (Populus nigra), and various other plants and trees.
As a rule the larva hybernates through the winter, is full grown in the following May, and the moth appears in July; but in Scotland the caterpillar does not spin its cocoon till September, hybernates in the chrysalis state, and emerges in the following June. The same is true of the Cornish Eggars; but along the coast of South Devon both varieties are to be met with.
The male Eggar seems to enjoy the bright sunshine, for I have seen large numbers flying over the rugged cliffs of the south-west throughout all hours of the day.