The moth appears during the winter months, and has been noted as early as October and as late as February. (Plate [58], Figs. 8-10.)
Generally distributed throughout the British Isles.
Northern Winter Moth (Cheimatobia boreata).
This species is generally larger than the last-mentioned. The fore wings are marked somewhat as in that species,
but they are paler in colour and more glossy; hind wings whitish and glossy. In the female, the wings are useless for flying, but still they are larger than those of brumata. The front pair have a blackish band. (Plate [58], Figs. 6 and 7 ♂, 5 ♀; ova. Plate [59], Fig. 1.)
The caterpillar is greenish, with a greyish stripe along the back, another edged above with yellow along the black spiracles, and a greyish line between the stripes; the head is black. It feeds, in May and June, on birch, and the moth does not appear until October or November.
At one time considered to be a purely northern species: the earliest known British specimens, four in number, having been captured at Petty Pool, Delamere, Cheshire, on October 31, 1848. It is now known, however, to have a wide distribution in the south of England. Northwards, its range extends throughout England and Scotland up to Moray. It is found in South Wales; also in Galway, Monaghan, and Connemara, in Ireland.
The Tissue (Triphosa dubitata).
The fore wings of this glossy species (Plate [60], Figs. 1, 2) are pale brown, tinged more or less strongly with rosy or purplish; there are numerous darker and paler cross lines, the most distinct and constant being the blackish basal, and the two forming the edges of the central band; the latter are marked with black; the submarginal line is whitish, wavy, and sometimes broken up into dots. The species varies considerably in tint, some specimens inclining to pale greyish brown, others to smoky brown. Hind wings, whitish grey, with several darker grey cross lines; in dark specimens these wings are smoky grey. Ab. cinereata, Stephens, is a small pale greyish form, almost without rosy tinge and with fewer cross lines.
The caterpillar (Plate [62], Fig. 1) is yellowish green with