This delicately marked species, better known, perhaps, as constrictata, Guenée (Plate [95], Fig. 4), has the fore wings whitish grey, with three slender blackish curved cross lines, and some less distinct greyish ones; the outer margin is slightly darker, and traversed by a wavy whitish line; discal spot black and conspicuous.
I have not seen specimens from the Hebrides, but, according to Barrett, these have a more decided grey tint.
The rather long, wrinkled caterpillar is dark green, inclining to yellowish between the rings, with a broad purplish red line along the back. It feeds on the flowers of wild thyme (Thymus serpyllum), in August and September.
The moth is out in June and July, and inhabits dry places where there is an abundant growth of wild thyme. It is easily alarmed, and quickly rises on the wing from its hiding-place among the herbage.
The species is, or has been, found in most of the southern counties of England, from Sussex to Cornwall, on the western side from Somerset to Westmorland, including North Wales and the Isle of Man; also recorded from Buckinghamshire, Yorkshire (Richmond), and Northumberland. In Scotland it occurs chiefly on the west to Ross, and in the Hebrides; in Ireland it is widely spread, but most frequently met with on the coast.
Bleached Pug (Eupithecia expallidata).
The ample wings light brown in colour, with large black discal spot, and smaller black marks on the front edge of the fore wings, distinguish this species (Plate [95], Fig. 7) from its closest British allies.
The caterpillar feeds, in September and October, on flowers of golden rod (Solidago virgaurea), but it will thrive on those of michaelmas daisy, and probably the asters of the garden. It varies in ground colour, but this is usually some shade of green, and there are brownish spots and lines on the back.
The moth is out from late June until August, and may be put up from among golden rod during the day, or netted as it flies about the plant in the gloaming.