The butterfly appears in July and August, and is very frequently met with throughout the country on heaths, commons, and downs, both on sandy and chalky soils. In many places it is the commonest of the "Blues." It has been found at Epping; Coombe Wood; Darenth Wood; Box Hill; Ripley, Surrey; Brighton; Lewes; Deal; Lyndhurst; Blandford; Brandon, Suffolk; Holt, Norfolk; Birkenhead; Bristol; Sarum, Wiltshire; Lyme Regis; Parley Heath, Dorsetshire; Manchester; York; several places in Scotland.
THE BROWN ARGUS. (Polyommatus Agestis.)
([Plate XIV]. fig. 6.)
Though this butterfly and the next are classed among the "Blues," from their possessing the same structure and habits, there is no trace of blue in the colouring of either sex, as in all the preceding species of Polyommatus.
In this species the colour of both sexes on the upper side is a warm, dark brown, having on all the wings a border of dark orange spots. The female hardly differs from the male, except in having this border broader, and more extended on the front wing; where,
in the male, it is sometimes very indistinct. The under side much resembles that of the female of Alexis, the border of orange spots being even more distinct on the front wing than on the hind one. It will be observed on referring to [Plate XIV]. that on the under sides of all the butterflies there figured, there is an irregular black spot situated near the front edge of the upper wing and midway in its length—this is called the "discoidal spot." It will also be observed that the common Blue (fig. 4) has, on the area of the wing, between the discoidal spot and the root of the wing, two spots, which are absent in this species. This forms a very ready mark of distinction, though it requires a good many words to explain it.
The caterpillar, which feeds on Erodium Cicutarium, and perhaps on Helianthemum (Rock Cistus), is green, with pale spots on the back, and a brownish line down the middle.
The butterfly appears in May and June, and again in August, and is common in very many localities in the south, being particularly abundant on the downs of the south coast and the Isle of Wight.