Mazarine Blue. 9, 11 male; 10, 12 female.
The butterfly emerges in about three weeks, so it will be seen that this species continues the caterpillar existence for something over ten months.
On the Continent there are two broods of the butterfly, and in England there appears to be a partial second flight in some years, as, for instance, in 1901, when captures in August were reported from Herts, Kent, Surrey, and Wilts. Its haunts are warm and sunny grassy hollows and slopes, and it is often common in such places on the chalk hills in the south, from the end of May to the end of June. According to Barrett it is scarce in the Eastern Counties; widely distributed but local in the Midland and Western Counties, even to Devon, and in Wales, where chalk or limestone is found; also in extremely restricted localities in Yorkshire, Lancashire, Cumberland, and Durham, and in various places in Scotland, extending as far north as Aberdeen. In Ireland it is much more plentiful, especially on the limestone of the west and on the coast hills near Belfast, and even frequents the sand-hills of the Dublin coast.
It is widely spread over Europe, except the Polar parts, and, apparently, the south of Portugal and Spain; its range extends eastward to Amurland, Mongolia, and China.
The Mazarine Blue (Nomiades semiargus).
The male is dull purplish-blue, narrowly bordered with blackish on the outer margin; the female is dark brown. On the underside both sexes are pale greyish-brown, with a bluish tinge at the base; there is a black discal spot and a series of black spots beyond, all ringed with white.
The egg is described as being white in colour and small, and round in shape.
The caterpillar is of a dingy yellowish-green, with darker lines on the back and sides; there are fine hairs on the body, and the head and spiracles are dark brown (Rühl).
It feeds in July and August on the flowers and seeds of thrift (Armeria vulgaris), kidney-vetch (Anthyllis vulneraria), and melilot (Melilotus officinalis).
The chrysalis is rather oval in shape, pale olive-green in colour when first formed, in September, but olive-brown later; it is attached by the tail to a stalk of the food-plant and has a silken girdle (Rühl).