The Long-tailed Blue (Lampides bœticus)
The male is purplish-blue suffused with fuscous, especially on all margins except the inner one; there are two velvety black spots encircled with pale blue at the anal angle of the hind wings, and a slender black tail, tipped with white, appears to be a continuation of vein 2. The under side is grey-brown, with numerous white wavy lines and broader streaks; there is a whitish band on each wing before the outer margin, and black spots as above, but these are ringed with metallic blue.
I have not seen any of the early stages of this butterfly. The caterpillar, which feeds upon the green seeds in pods of the Leguminosæ, including the garden pea and the lupine, is figured on Plate 102. It is described as being green or reddish-brown in colour, with a dark stripe on the back, double oblique lines on the sides, and a white line below the yellow spiracles; head black. The chrysalis is of a red or yellowish colour, and dotted with brown. It has a silken girdle and is said to be attached to a stem, as shown in the figure, but probably it is more often fixed up among the withered leaves of the food-plant. Two of the earliest known British specimens of this butterfly were taken by the late Mr. Neil McArthur on August 4th and 5th, 1859, on the Downs at Brighton; the third example was captured by Captain de Latour at Christchurch, where it was flying about a plant of the everlasting pea in his garden on August 4th of the same year. Newman has noted that in that particular year the butterfly was very abundant in the Channel Islands and on the coast of France. No other specimen seems to have been observed in England until 1879, in which year one was taken at Freshwater in the Isle of Wight on August 23rd. In 1880 a specimen was captured in a garden near Bognor, Sussex, on September 12th. On October 2nd, 1882, one was obtained at West Bournemouth. Three were netted in 1893, one of these in late August, and one in the third week of September, both in Sussex; the third was taken in Kent (inland) in September. In 1899 a specimen was found at Winchester on September 1st, and one at Deal on the 16th of the same month; each of these, curiously, was sitting on a window. On August 2nd, 1904, one example was taken in a garden near Truro, Cornwall. In addition to the above, single specimens have been reported as taken at Brighton, July, 1890, and at Heswell, Cheshire, in 1886 or 1887.
It will thus be seen that the occurrence of this butterfly in England is exceedingly infrequent. The species is common in Africa and in Southern Europe; thence it extends eastward through Asia to China and Japan, and southwards to Australia. It is also found in the Sandwich Islands. It is believed to be migratory in its habits, and it is supposed that the occasional specimens that arrive in this country come to us viâ the west coast of Europe.
In its proper home there is a succession of broods of the butterfly, and if by chance a few females were to visit this country in the early summer, they most probably would lay eggs, and the caterpillars resulting from these would almost certainly be able to feed up and attain the perfect state here. So far there is no reason to suppose that the caterpillar has ever occurred in England.