The moth is out in June and early July, occasionally in late May in some southern localities. Individuals of a second emergence sometimes appear in August and September. It
rests by day on tree-trunks or in hedges, and flies at night. Widely distributed over the British Isles, but, except perhaps in the highlands of Scotland, not very common.
Blue-bordered Carpet (Mesoleuca bicolorata).
The more usual form of this pretty little species is shown on Plate [82], Figs. 3 and 6. In the type the central band is only represented by a spot on the front margin of the fore wings; in ab.parvula, Retz = rubiginata, Hübner, there is also a portion of the band showing on the inner margin. Ab. plumbata, Curtis, from Scotland has the central band entire and the ground colour inclining to creamy white. In ab. fumosa, Prout, the usual white parts of the wing are smoky or dark lead colour (Fig. 9). Barrett mentions a form with all the wings smoothly smoky black; markings of the fore wings olive brown, margined with slender stripes of smoky white.
The long, thin, caterpillar is green, with a darker stripe along the back, and a yellowish green stripe on each side; two points on the last ring. It feeds on alder, birch, sloe, and crab; also in orchards and gardens on plum and apple: April to June.
The moth is out in July and August. It appears to occur most freely in districts where alder is plentiful, but it is not uncommon in country lanes, especially where these are rather moist. It is one of the earliest Geometrid moths to get on the wing, as it is generally active well before dark. Decidedly more common in some districts than in others, but it may be said to be generally distributed.
The range abroad extends to Eastern Siberia, Amurland, and Japan, but the ab.fumosa is only known from Britain.
Pretty Chalk Carpet (Melanthia procellata).
From almost any well-grown hedgerow, in which traveller's joy, or old-man's beard (Clematis vitalba) is plentiful, throughout the southern counties of England, this species (Plate [82], Fig. 14) may be disturbed by the beating stick. It is generally to be met with in July and early August, but may be obtained in forward seasons, or in sheltered localities, at the end of June.