white, chequered with brown. Sometimes the freckling is heavy and the clouding very dark, becoming almost black on the outer margin; such specimens seem to be referable to var. scincula, Hübn. In another form the fore wings are ochreous brown, with very tiny freckling and only light clouds on the upper part of the outer margin. The hind wings in all the forms are pale whitish brown, with a black central dot, and brown marginal line; in the darker specimens these wings are clouded or suffused with dark brown (Plate [71]).
The egg is pale yellowish when laid, but changes afterwards to reddish. The full-grown caterpillar is pale brownish, marked with darker or reddish brown on the back and sides, and raised spots; there are double-pointed humps on rings two and three, and a similar but smaller elevation on ring eleven. In the younger state the caterpillar is blackish, with whitish marks on the fourth, seventh, and eighth rings, and some white dots on the end rings. It feeds on the upper surface of the leaves of birch in June and July, and again in August and September.
Chrysalis, reddish brown, the ring divisions blackish grey; powdered with whitish, and appearing as though dusted with flour. Attached by the anal spike to the interior of the silken web-like cocoon. In the Figure (Plate [69]) the pupa is shown hanging from the ruptured cocoon, upon the covering leaf of which a half-grown caterpillar is depicted.
The moth is out in May and June, and a second generation appears in August. It is not uncommon in most birch woods, and on heaths and commons, where birch flourishes; but the perfect insect, which rests on leaves and twigs of trees and bushes, and the herbage under them, is not so frequently or so easily obtained as the caterpillars. The latter may be searched for in the daytime, or they may be dislodged by beating.
Widely distributed throughout England, but local or scarce in Lancashire and Yorkshire and northwards; also, according to
Barrett, in Devonshire and in the fens of Norfolk and Cambridge. It occurs in the Clydesdale district, Ross, Argyllshire, and Sutherland in Scotland; and in Ireland it seems to be widely spread and common in some localities.
The Chinese Character (Cilix glaucata).
Probably in reference to the grey-brown oval blotch on the middle of the white fore wings, this moth was known to the older entomologists by the English name of "Goose-egg." On the blotch, however, there are silvery marks on the veins, and below it (often attached) there is a blackish blotch with some bluish silvery scales upon it. These markings probably suggested to Haworth the name Chinese Character by which it is commonly known (Plate [71]).
The caterpillar is reddish brown, with a darker line along the back, and a paler patch on rings three to five, extending as a narrow stripe to the dark-brown spiked tail; two raised warts on rings two and three, with a white dot between the hinder pair. Head darker brown, paler in front. It feeds in June and early July, and in September and October, chiefly on hawthorn and sloe, but it will also eat apple and pear. The chrysalis, which is enclosed in a brown, rather tough, silken cocoon, spun up among leaves or under loose bark, is greyish on the wing covers, and reddish on the body.
The moth is out in May and early June, and again from late July well into August. Sometimes it may be seen resting on a leaf in a hedgerow. When disturbed in the daytime, which may happen where one is beating the bushes, it falls, rather than flies, to the ground. At night it may be netted as it flies along the hedgeside or wood borders in almost every county of England and Wales. In Scotland its range seems not to extend north of Clydesdale. Kane states that it is "widely spread, but not generally at all numerous" in Ireland.