Family—Bombycidæ
This family contains eleven thick-bodied moths, mostly of large size, in which the predominating colours are greys and browns. Their hind wings are generally paler than the front pair, and less distinctly marked; and the antennæ of the males are pectinated.
The caterpillars are very hairy, but the hairs are uniformly distributed, and not arranged in tufts as in the larvæ of the last family.
The chrysalides are inclosed in silken cocoons, but are not hairy.
We shall briefly examine three of the members of this family.
The Oak Eggar (Bombyx Quercus)
The male of this species is shown on [Plate X] (fig. 5). The female is much larger, and of a pale tawny colour.
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 (Cratægus 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.