The Grey Dagger (Acronycta psi).
The ground colour varies from whitish to blackish grey, Var. bivirgæ, Tutt, is similar to var. virga of the last species.
In var. bidens, Chapman, the first cross line is double, enclosing a pale stripe; the upper part of second cross line is more angled, and the dagger mark at the anal angle is much shortened.
The caterpillar has a taller and more slender hump on ring four, and the stripe along the back is clear yellow, with black edged red spots on each side of it. Generally distributed, and often common.
The moth is shown on Plate [100], Fig. 11; and the caterpillar and chrysalis on Plate [101], Figs. 5 and 5a.
The Light Knot Grass (Acronycta menyanthidis).
Portraits of this moth will be found on Plate [103], Figs. 1♂, 2♀. Several modifications have been named, the most important of these are var. scotica, Tutt, which is larger and brighter than the type, with the markings clear and distinct; var. suffusa, Tutt, is much suffused with black. The former is chiefly found in Scotland, and the latter in Yorkshire.
The caterpillar is black or sooty-brown, with a red stripe, or blotches, low down along the sides; hairs black or red-brown. In August and September feeding by day on sweet-gale or bog myrtle (Myrica gale), bilberry, heather, dwarf sallow, etc. The moth flies in June and July, and may be found on the mosses and moorlands of North England and Scotland. It rests by day on rocks, stones, and, where they are handy, on posts and rails. I found several on Danes Moss, Cheshire, sitting on a derelict tub. Also occurring in Ireland, but not common.
The Scarce Dagger (Acronycta auricoma).
The pale grey, darker-mottled moth depicted on Plate [103], Fig. 3, is very local, and only occurs in some of the woods of