the outer one. In some specimens there is a distinct submarginal line, but this character is only faintly in evidence as a rule, and occasionally it is entirely absent. (Plate [143], Fig. 6.)
The caterpillar feeds in June, sometimes earlier, on bracken or brake-fern (Pteris aquilina). It is olive green marked with reddish brown lines, and there is a whitish line under the black spiracles.
In most English and Welsh localities where bracken is plentiful, this moth should be found in May and June; also in the south of Scotland, but its occurrence in that country north of Clydesdale appears to be only casual. It is common in several parts of Ireland.
The distribution abroad includes Amurland and Japan.
Latticed Heath (Chiasmia (Strenia) clathrata).
In its ground colour this species (Plate [143], Figs. 7, 8 ♂, 9 ♀) varies from ochreous of some shade to white. The dark-brown or blackish cross lines and veins give a latticed appearance to the wings, hence both the Latin and popular names for this insect. There is much variation in the width of the cross markings; sometimes two or more unite and so form bands; more rarely, perhaps, the outer lines are absent, and the others broken up into dashes; or the blackish cross lines may be slender and the veins remain of the ochreous ground colour (ab. radiata, Haworth). A less frequent aberration has the wings dark brown or blackish all over, except a row of whitish or ochreous spots on the outer margins (ab. nocturnata, Fuchs = nigricans, Oberthür).
The caterpillar, which feeds on clovers and trefoils, is green, with white lines along the back and sides; the slightly notched head is rather glossy, and the mouth is brownish: June to September, in two broods.
The first generation of the moth is out in April and May, and
the second in July and August. It may be found in clover fields and on chalk slopes, etc., where the food plants flourish; although it is an active day flyer, it is not difficult to capture with the net. It is most plentiful in southern and eastern England, but its range extends throughout the United Kingdom to Clydesdale, and the species is widely distributed in Ireland.
The distribution abroad extends to East Siberia, Amurland, and Japan.