Heath Rivulet (Perizoma minorata).
The British form of this species (Plate [83], Figs. 9, 12) is rather smaller and darker than typical minorata, Treitschke, and as Stephens has figured and described it as ericetata, this name should be adopted for our native race.
The white fore wings have a greyish basal patch and three bands of the same colour; the outer one is traversed by a more or less distinct wavy whitish line; the band nearest the basal patch is sometimes very faint; more rarely the markings are
absent from the central area of the wings (ab. monticola, Staud.), and a specimen approaching this form has been taken in Perthshire.
The caterpillar is pale green with a dark-green edged ochreous brown stripe along the middle of the back, and green stripes on each side; the usual dots are black, and the plates on first and last rings are brown, as also is the head. It feeds, in September, on the seeds of eyebright (Euphrasia officinalis).
The moth is out in July and August, and is found very locally, flying in the late afternoon among its food plant, on the moorlands and pasture-grounds of Northumberland, Cumberland, Durham, and Westmorland; and has been reported from Hawkshead, in Lancashire. In Scotland, it is common in suitable parts of Roxburghshire and several localities in Clydesdale; thence widely spread to the Orkneys. Only noted from the Mourne Mountains in the north-east of Ireland, but probably to be found in other parts of that country.
Pretty Pinion (Perizoma blandiata).
This species (Plate [83], Figs. 7, 8) is also known as adæquata, Borkhausen, the name under which it is catalogued by Staudinger. As a rule the central band on the whitish fore wings is only represented by a round, or sometimes triangular, blackish spot on the front margin, a smaller blackish mark on the inner margin, and some dusky clouding between these two portions. In specimens from the Hebrides the band is more or less complete, and in some of them it is very much narrowed, especially towards the inner margin (ab. coarctata, Prout).
The caterpillar is green, with three crimson lines, the outer ones bent inwards to the central one on the middle of each ring; two lines above and one below the yellowish spiracular line are pink; head green, tinged and freckled with pink. It
feeds in September on the flowers and seeds of the eyebright (Euphrasia officinalis).