The Dingy Skipper (Thanaos Tages)
The wings are fuscous, with darker fuscous transverse bands on the middle third of the fore wings; the space between these is sometimes, and in both sexes, whitish; there are some whitish spots on the outer band, usually towards the costa, but occasionally on the middle also, and a series of white points on the outer margin of all the wings. The hind wings have a whitish discal dot and a band beyond the middle, which is almost parallel with the outer margin. The male has a well-marked fold on the costa (Plate 122).
The egg is whitish-green when freshly laid; it afterwards changes in colour to orange. The caterpillar is yellowish-green with a darker line along the back and a paler line on each side; the spiracles are red and edged with whitish. The head is pale brown, striped and marked with purplish-black. The body, together with the head, is covered with a short whitish pile. It feeds on bird’s-foot trefoil (Lotus corniculatus) from June until August, when it hibernates. I have not seen the chrysalis, but it has been described as dark green with the body tinged with rosy red.
The butterfly is on the wing in May and June; in some seasons it has been seen as early as the end of April. Very occasionally, perhaps, there is a partial second flight in August. It has been reported as plentiful at Lyme Regis in August.
I took one or two specimens about the middle of August, 1903, in the New Forest district, and in the same month of 1905 one of two caterpillars sent to me by Dr. Chapman pupated in August, and the butterfly emerged some time in the autumn, as I found it dead in the box early in October. Both the caterpillars had spun together sprays of the food-plant as shown in the figure, Plate 123. One was removed for its portrait to be taken, and it was supposed that the other bundle contained a caterpillar also, and was not examined.
The butterfly affects open places in, or the edges of, woods in chalky districts, also the slopes of chalk downs and other hillsides, as well as railway banks and even rough fields. It evidently delights in sunshine, and may often be seen basking on a stone or the bare earth. When at rest at night or on dull days it sits on a dead seed-head or grass glume, with the wings closed down over its back like a noctuid moth, and is then difficult to detect until the eye becomes accustomed to its appearance. It is widely distributed in Great Britain, but it is more at home on chalk and limestone than elsewhere. In such localities as the fens of Norfolk and Cambridge it is scarce, and seems to have a rather limited distribution in Ireland, in which country Galway is its headquarters, according to Kane.
Abroad, it is found throughout Europe, and its range extends to Western Asia.