This moth is so common and so widely distributed that it is almost sure to be taken by the young collector during his first season. Its wings are scalloped on the hind margin, and their colour light ochreous, often tinged with pink or olive green, and marked with dark
brown as shown in the illustration. It is double brooded, the first brood appearing in May and June, and the second in September and October.
The caterpillar is green or olive brown, and thickly covered with white spots. It feeds on groundsel (Senecio vulgaris) and many other low plants, the first brood throughout the winter from November to April, and the second in July and August.
The Grey Arches (Aplecta nebulosa)
The fore wings of this moth vary from greyish white to a rather dark smoky tint. The markings are of a darker colour, and are also subject to considerable variation. The orbicular and reniform spots are large, and paler than the ground colour; and several zigzag or scalloped lines, more or less distinct, cross the wings transversely.
The larva is brown, with a lighter line down the back. On each of the segments five to eleven is a dark lozenge-shaped spot, bisected by the dorsal line; and on the second segment is a shining plate and a triangular mark. It feeds on the dock (Rumex), and various other low plants during the autumn; and, after its hybernation, on the leaves of the sallow (Salix Caprea), birch (Betula alba), and whitethorn (Cratægus oxyacantha). It is full grown in May, when it burrows into the ground to undergo its metamorphoses.
The moth flies during June and July, and is common in nearly every part of Great Britain. Large numbers may be obtained by searching fences and tree trunks about midsummer.