The rather spindle-shaped caterpillar is purplish brown, inclining to greenish on the sides and below at each end; on the back of the middle rings are whitish V-marks, and the last three rings incline to purplish red above (adapted from Fenn). It feeds on the young leaves of alder, birch, and sallow, in July and August. The moth is out in June, and hides by day among the bushes, but may be seen occasionally
on tree-trunks. Its haunts are in damp woods and plantations, and it occurs in most of the English and Welsh counties, although it is rarely common, except in the south of England. In Ireland it has been noted as scarce in counties Wicklow, Kerry, Galway, and Sligo.
The range abroad extends to Amurland and Japan.
Blomer's Rivulet (Asthena blomeri).
The earliest British specimens of this species (Plate [91], Figs. 8 ♂ and 10 ♀) were taken in Castle Eden Dean, Durham, and among the first to detect these was Captain Blomer, after whom Curtis named the species in 1832. It is still found in that locality, but is also known to occur in Cumberland, Lancs., Yorks., Derby, Staffs., Merionethshire, Worcester, Hereford, Glamorgan, Gloucester, Somerset, Devon, Wilts., Oxford, and Bucks.
The slender caterpillar is yellowish green, generally marked with pinkish-brown on the back, but most or all such markings may be absent. It feeds, on wych elm (Ulmus montana) (Plate [90], Fig. 1), in August and September. The moth is out in June and July, earlier or later in some seasons. As a rule, it sits on the trunks of beech trees, but I have seen it on the stems of cherry and fir, though hardly ever on wych-elm. Occasionally, newly emerged specimens have been noted on the leaves of dog's mercury (Mercurialis perennis).
The range abroad extends to Amurland and Japan.
Lime-speck Pug (Eupithecia oblongata).
The characteristic features of this white, or greyish white, species (Plate [93], Figs. 1 and 4) is the bluish grey blotch on the front margin, in the lower end of which is the black discal
spot. Occasionally, the blotch is much reduced in size, but it is usually large, and sometimes there are indications of a dusky stripe from it to the inner margin.