The Dark Green Fritillary (Argynnis Aglaia)
This butterfly is bright fulvous in the male, paler in the female; the latter sex is blackish towards the base, and has paler spots on the outer margin. The black marking is pretty much as in the previous species, but the male has the black scales (androconia) on veins 1 and 2, and these are less conspicuous. The basal two-thirds of the hind wings is greenish on the under side. The silvery spots are arranged in fairly regular series, and there are no silvery centred red spots between the two outer series. The blackish crescents on the outer margin of the fore wings are edged with silver, but this is chiefly towards the tips of the wings.
There is some variation in the tone of the ground colour, lighter or darker than normal in both sexes; the female seems to be the most variable in this respect, and sometimes, especially in the north, examples of this sex are much suffused with blackish or greenish-black. Occasionally the colour is quite pale, as shown in the middle figure on Plate 61, and sometimes it is clouded with greyish. The black spots are apt to run together, and so form bands and blotches. An example of this kind of aberration is shown on the plate.
Var. charlotta differs very little from the type on the upper side, but on the under side of the hind wings the basal silvery spots are united, as shown in the upper reverse side figure on the plate. This variety was known to the entomologist of Haworth’s time as the “Queen of England Fritillary,” and there is a figure of it in Sowerby’s “British Miscellany,” which was published in 1806.
The egg is yellowish when first laid, and a day or two afterwards violet-brown rings appear above the base and the apical half. It is ribbed and finely cross-ribbed, and some of the ribs are continued to the truncate and slightly depressed top.
When full grown the caterpillar is shining purplish-grey, thickly mixed with velvety black; the grey is most in evidence between the rings and along the lower part of the sides. There is a yellow stripe along the middle of the back, and this has a central black line of irregular width; along the lower part of the sides there is a row of reddish spots, and these are connected by a fine yellowish line. The black spines are branched, and, except on the first three rings, which have only two rows, arranged in three rows on each side of the yellow stripe. The head is glossy black, and, like the body, hairy. (Adapted from Buckler.)
It feeds in May and June on dog-violet, and has been reared on garden pansy. The chrysalis has the head, thorax, and wing-cases black, very glossy, and marked with pale brownish; the body is pale brownish, and the points black. Suspended in a tent-like arrangement of leaves.
Moorlands, downs, sea-cliffs, and flowery slopes are the kind of situations most to the fancy of this agile butterfly. It is on the wing in July and August, and is much more easily seen than caught. However, it is rather fond of perching on the taller kinds of thistles, and is then not difficult to capture, if quietly approached. It is common locally in most of the English and Welsh counties. In Ireland it seems to be chiefly attached to the coast, and is plentiful in some of its localities. In Scotland it occurs in many suitable districts, but Skye is the only one of the isles from which it has been reported. Its distribution extends through Europe and Asia to Amurland, China, and Japan.