The Marsh Moth (Hydrilla palustris).
The fore wings of the male of this species (Plate [153], Fig. 2) are greyish brown in colour, and more or less tinged with violet; the cross lines are dusky, and the reniform and orbicular stigmata are represented by black dots, the former the larger; hind wings whitish with a smoky tinge. The female is much smaller, darker, and the cross lines heavier; hind wings blackish grey.
Stainton ("Manual," 1857) refers to a specimen taken at Compton's Wood, near York, and this, no doubt, is the same as
that stated by Barrett to have been captured in a moist place at Stockton-in-the-Forest, about four miles from York, certainly before the year 1855. Then there is a record of a specimen from Quy Fen, Cambridgeshire, in May, 1862. Seven years later the late Mr. C. G. Barrett took a specimen as it fluttered about a gas-lamp outside Norwich. In 1877 and 1878 the use of bright collecting lanterns in Wicken Fen may have led to the capture of nearly twenty Marsh Moths, anyway it seems to have been a record for the time.
Very few specimens were taken in the fens between the year last mentioned and 1898, when the total secured by several collectors visiting the fens in June of that year amounted to something like fifty examples, all males. Two female specimens were captured in the Carlisle district, one in 1896, and the other in 1897. No male was noted in that locality until 1899, when a specimen was netted as it flew along a hedgeside at night, on May 20. Two other males have since been taken there, in much the same way. The life history of the species is little known. Hofmann describes the caterpillar as reddish brown with white dots, and a white line along the middle of the back; spiracles and head black. It feeds in the summer on low-growing plants in meadows, and hides in the daytime on the underside of a leaf.
The range of the species abroad extends to Siberia and Amurland.
The Brown Rustic (Rusina tenebrosa).
Here, again, the female is smaller than the male, as will be seen on Plate [153], Figs. 4 ♂, 5 ♀. Sometimes the general colour of the fore wings is of a blacker tint, and in such specimens the fine black cross lines are obscured.
The caterpillar is dark cinnamon brown; three whitish lines on the back, the central one, most distinct on the front rings, is edged on each side with dark brown, and the shading of the outer lines is interrupted by oblique pale dashes; head, shining dark brown, almost blackish. It feeds on grasses, and many low-growing plants from August to May. (Plate [152], Fig. 4.) The moth flies in June and July, sometimes earlier. The species is generally distributed over nearly the whole of England, but more local in the north than in the south. It is found in North and South Wales. In Scotland it is locally abundant and widely distributed up to Ross, and occurs in the Hebrides. It is also widely spread in Ireland, and common in some parts.
Umbratica, Goeze, is said to be an earlier name for this species, and will probably have to be adopted.