The moth emerges in June, and may be seen sitting on walls, fences, trees, or on the herbage growing on hedge banks; or even on the bare ground. It often flies into houses when lighted up, and is a frequent attendant at the public gas lamps and electric lights. The geographical range of this species extends through Northern and Central Europe southward to North-West Africa, and eastward to Amurland.
The Water Ermine (Spilosoma urticæ).
The specimens of this white moth, depicted on Plate [75], are of the form usually met with in Britain. To Haworth, Stephens, and other early entomologists this was known by the English name of the "Water Ermine" (S. papyrata, Marsham), whilst a rarer form—with a minute dot on the disc of the fore wings, and three dusky spots on the hind wings, as in the White Ermine—was the "Dingy White" of Haworth. Occasionally specimens are obtained with extra black spots on the basal and front areas of the fore wings.
Caterpillar, dark brown with a purplish tinge, the hairs, arising in spreading tufts from black warts, are dark brownish; spiracles white; head black and glossy. Feeds in July and August on a variety of marsh plants, among which are yellow loosestrife (Lysimachia vulgaris), mint (Mentha aquatica), lousewort (Pedicularis), water dock (Rumex hydrolapathum), and iris. It seems to affect plants growing under bushes, rather than those more exposed. It is, presumably, not difficult to rear in confinement, as there is a record of eight broods belonging to three generations, and all descendants of a captured female, having been reared by Mr. Bacot. Chrysalis dark reddish brown, in a cocoon similar to that of the last species.
| Pl. 76. |
| Buff Ermine Moth. |
| Eggs, natural size and enlarged; caterpillar, chrysalis and cocoon. |
| Pl. 77. |
| Buff Ermine Moth and varieties. |
The moth, which emerges in June, is rarely seen away from its favourite haunts, which are marshes and fens; its English name is therefore a very appropriate one. It is not often observed in the daytime, but is on the wing early in the evening, and later on is pretty sure to be attracted to any strong light that may be set up in its neighbourhood. The best localities for the species seem to be the fens of Norfolk and Cambridge, but it used to be fairly plentiful in many suitable parts of East Kent, and no doubt still occurs in some of the marshes between Dartford and Gravesend: it is found in Sussex in the Lewes and Brighton districts, and has been recorded from Kimmeridge in Dorsetshire, from the Isle of Wight, from near Burton-on-Trent, from the Lancaster district, and from Pembrokeshire, South Wales. In Scotland it is rare, and, with the exception of one example reported as taken in an illuminated moth trap at Clonbrock, May, 1896, not known to occur in Ireland.