The Lulworth Skipper (Adopæa Actæon)
Compared with the other two species on Plate 125, the coloration of this butterfly is somewhat dingy; it is, however, enlivened, especially in the female, by a short dash and a curved series of orange spots in the upper half of the fore wings. The male has a black sexual mark which is very similar to that of the Small Skipper. There seems to be very little to note in variation, except that the orange markings referred to are subject to modification, and in the male may be altogether absent. An example taken at Swanage, in 1903, had the wings on the left side male, and those on the right side female.
The egg, figured, from a photograph, on Plate 124, is whitish, faintly tinged with yellowish.
The mature caterpillar is pale greyish, or yellowish, green, with the dorsal vessel darker, and edged with a slender pale yellow line on either side, and enclosing a pale longitudinal line along its middle. A narrow yellowish line runs above on the side and a broader one below. The two dorsal lines are prolonged as far as the middle of the head, and run to the end of the flat anal shield, which is narrowly edged with pale yellow. The head is greenish with two yellowish lines. The two snow-white patches on the under side of the ninth and tenth rings of the body are conspicuous as in lineola, sylvanus, and comma. This white substance is spread out at the tail end of the caterpillar of actæon, when it has formed its chrysalis case (Zeller).
Buckler, referring to four caterpillars found on Brachypodium sylvaticum, June 11, states that they completed their growth on a diet of Triticum repens. They ate out wedge-shaped portions from the sides of the grass blades, and when they had finished their repast, they crawled down to the middle of the blade, and there spun a coating of white silk from one side to the other, causing the two edges of the blade to draw together a little, and then in the silk-lined hollow they rested until hunger obliged them to ascend the blade again for another meal. About June 23 they had ceased to feed, and were beginning to fasten themselves within more closely constructed retreats, formed where two blades of grass obliquely crossed each other. The colour of the chrysalis is similar to that of the caterpillar, and the lines are faintly traceable. The butterflies appeared July 14 to 18, emerging at night, and ready for flight in the morning.
This insect received its English name in 1832, when it was first discovered in this country at Lulworth Cove, in Dorsetshire. It has since been found to occur at Durdle Cove, and the Burning Cliff, Weymouth, and the latter locality appears to be its most eastern limit. Its range extends westward along the coast of Dorsetshire and Devonshire to Sidmouth, Seaton, and Torquay; and there are records of its having been observed in Cornwall. According to Mr. E.R. Bankes, as quoted by Barrett, this butterfly is not confined to the coast line in Dorset, but is to be found in two or three spots along the chalk range of the Purbeck Hills, at a distance of four or five miles from the sea. He also states that the species is only single brooded, that the best time for it is from the beginning of July to the middle of August, and that the food-plant of the caterpillar is Brachypodium pinnatum.
The blossoms of rest-harrow (Ononis arvensis) are said to be the particular vanity of the butterfly, and it is seldom found visiting any other flower. Abroad the species is not especially attached to the sea-coast, but occurs inland throughout Central and Southern Europe, its range extending to Asia Minor and Syria, and also to North-West Africa.