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).
This butterfly (Plate 115) is the cymon of Lewin, who, writing in 1795, considered it very rare. In 1828 Stephens refers to it as scarce and local, “found in chalky districts in Norfolk, Cambridge, Yorkshire, and Dorsetshire; also near Brockenhurst and Amesbury, Hants; and on Windlesham Heath, Surrey, towards the end of May and of July.” Newman (1871) adds Warwickshire, Herefordshire, Gloucestershire, Monmouthshire, Glamorganshire, Somersetshire, and Lincolnshire. Curtis gives Leicestershire and Worcestershire. It seems to have been fairly common, and even plentiful in some years around Glanville’s Wotton, Dorset, but has not been seen in that district since 1841; at Wotton-under-Edge, Gloucester, it was not uncommon up to 1858; as late as 1864 it occurred at Epworth, North Lincolnshire. Probably the latest captures in Britain were the specimens taken in Glamorganshire in the years 1874-77. Tutt mentions that the butterfly was taken near Cuxton in Kent, some thirty-five years ago, but it has not since been seen in that locality.
Occurs in May and June and again in July and August over the greater part of Europe; its range extends to Asia Minor, and eastward to Siberia, Mongolia, and Amurland.