Four specimens are depicted on Plate [138]. Figs. 2 and 3 represent the sexes of the type form, and Figs. 4 and 5, the greenish-grey var. olivacea, Stephens. Both forms may be paler or darker, but the green tinge is apt to fade out. Var. suffusa, Tutt, is a dark greyish suffused form.
The caterpillar is green, inclining to bluish green above; the lines on the back are whitish, edged with dark green; that along the black-margined white spiracles is white, shaded above with dark green. It feeds on dock, dandelion, groundsel, etc.; also on sallow and hawthorn, from April to June. The moth is out in August and September. It prefers the open country to woodlands, and is often seen resting on rocks, stone, or other walls, and buildings. Except that it occurs in Devon and Dorset, the species seems to be absent in the south of England, but its area of distribution extends in the British Isles from the Midlands of England to Moray and Ross in Scotland, and to Ireland.
The Black-banded (Polia xanthomista).
The form of this species occurring in Britain is var. nigrocincta, Tr. (Plate [140], Figs. 2, 3), which is pale grey, spotted with white, and clouded on the central area with black. The typical yellow flecking and dotting is in this form usually sparse, but occasionally it is prominent. A specimen reared from a caterpillar taken in the Isle of Man was suffused on the fore wings with bright orange.
The caterpillar is ochreous brown, varying in tint, above and pale green below the brown spiracles; the head is rather yellowish and very glossy. It feeds on sea thrift (flowers), and plantain in its haunts, which are the rocky coasts of Cornwall, North Devon, and the Isle of Man. In confinement it will eat groundsel, dock, dandelion, lettuce, etc. Usually the caterpillars do not hatch out until the spring, and then feed until June or July; but they have been known to hatch in the autumn, and then to hibernate. The moth flies in August and September, but, although it has been taken at sugar and light, is more frequently reared from caterpillars, which are readily found at night by those who may undertake the sometimes
hazardous business of collecting them. The earliest known British specimen was taken at a lighthouse near Padstow in Cornwall, and five years later the moth was bred from a caterpillar found in the Isle of Man. In 1880 a specimen was taken at sugar in the middle of a small wood in South Pembrokeshire. According to Hampson this, and the other two species usually included in Polia, are referable to Antitype, Hübn. On the same authority nigrocincta, Treit., is the earlier name for the present species, as the figure of xanthomista, Hübn., was not published until 1827.
The Sprawler (Brachionycha (Asteroscopus) sphinx).
The black streaked and dotted, pale brownish grey moth (Plate [138], Fig. 8) occurs, more or less locally, in most of the English counties from Norfolk, Huntingdon, and Oxford, southwards; and from Gloucester northwards through Hereford and Worcester, to Cheshire, Lancashire, Yorkshire, to Darlington in Durham, and Cumberland. It is, however, rare in the northern counties. The caterpillar is yellowish green; three whitish lines on the back, the central one broadly edged with green on both sides, and the others inwardly by a dark line; the front ring is edged with whitish, and the head is greenish. It feeds on the foliage of various trees, including oak, beech, elm, ash, sallow, lime in May and June. The moth flies in November and December.