The green caterpillar has a yellow line running down the middle of a black stripe along the back, and this stripe is
bordered on each side with yellow, and broken up by the yellow ring divisions; head, with a black spot on each side. It feeds, in July and August, on alder.
The moth is out in June and early July, and will be found in almost every locality in England where the alder flourishes, most plentifully, perhaps, on the eastern and western sides. It has been recorded from North and South Wales, but it does not seem to have been noted from Ireland or Scotland.
The range abroad extends to Amurland and Japan.
Small White Wave (Asthena candidata).
The delicately lined white moth shown on Plate [91], Figs. 5 ♂ and 6 ♀, is chiefly a woodland species. It is generally common in the south of England, occurs more or less frequently throughout the northern half, and is widely distributed in Wales. In Scotland, it is said to be locally common in Clydesdale, and to be found in Arran and in Perthshire. It is plentiful at Dromoland, co. Clare, Ireland, not uncommon in parts of Galway, and once recorded from Wicklow.
The caterpillar is found, in July and August, on birch, hazel, and wild rose. In general colour it is green, inclining to bluish at each end, and tinged with yellowish along the ridge on the sides; the back is marked with crimson. (Plate [90], Fig. 2, after Hofmann.)
The moth is out in May and June, and sometimes July, and individuals of a second generation occasionally appear in August or September.
Small Yellow Wave (Asthena luteata).
This pretty little species (Plate [91], Figs. 2 and 4) has the pale yellowish wings marked with ochreous brown lines, which vary in thickness, and a dash of the same colour on the fore wings, from the central pair of lines to the middle of the outer margin.