The Camberwell Beauty (Vanessa Antiopa)
This is a large and handsome insect; its chocolate-brown wings are bordered with ochreous speckled with black scales. The border is variable in width, and this is occasionally so wide that it partly or completely hides the blue spots, which in the ordinary form are placed on a dark band just before the ochreous border. Such specimens are known as var. hygiæa or var. lintneri (Plate 41); but in the former form the yellow spots on the front edge of the fore wing are absent, and in the latter variety these spots are sometimes united and form a blotch. One authority states that the proportion of these extreme variations in nature is about 1 in 500. The same form may be produced by subjecting summer chrysalids to a temperature of about 110° Fahr. during three to five consecutive days, the chrysalids being placed in this heat four times a day, and for a period of one hour each time. Dr. Max Standfuss, who has made many experiments with this and other butterflies, states that the result of such treatment as that adverted to, and as regards this species, has been the production of as many as seven of the varieties among forty specimens. It would seem probable, then, that the varieties occurring in the open are from chrysalids that received a greater amount of heat than those that produce the ordinary butterfly.
It has been stated that the borders are ochreous, but this only applies to the specimens seen in the summer or early autumn. The butterflies hibernate, and when they leave their winter retreats in the spring, the colour of the border is considerably paler and often even white. For some time it was considered that white borders were a peculiarity of the British Camberwell Beauty and stamped it a genuine native. Probably there are some who may still hold this opinion. An example of each form is represented on Plate 43, the upper one was taken in the spring, and the other in the autumn. Both belong to Mr. J.A. Clark, to whom I am indebted for their loan.
The egg is at first deep ochreous yellow, changing through olive brown to red brown, and a day or two before the larva hatches out becoming leaden grey. The ribs, which are eight or nine in number, are most prominent below the top, and disappear before the base is reached. The eggs are laid on twigs or stems in small batches of 30 or 40 up to large ones of 150 to 250.
The caterpillar has been described by Mr. Frohawk, who gives a full account of the life-history of this species in the Entomologist for 1902 and 1903. The following is an abridgement of his description.
The head is bilobed, having a deep notch on the crown, and of a dull black colour, covered with black warts, each emitting a white hair. The ground colour of the body is deep velvety black, and densely sprinkled with pearl-white warts, each emitting a fine white hair, some being of considerable length, and the majority slightly curved. Down the centre of the back is a series of rich deep rust-red shield-like markings, which commences on the third segment and terminates on the eleventh segment. In the centre of the anal segment is a shining black dorsal disc, much resembling the head; the legs are black and shining, and the four pairs of prolegs are rust colour, with a polished band above the feet, and the anal pair are black with pale reddish feet.
The caterpillars feed on sallow, willow, birch, and elm. They cover the leaves of their food-plant with a silken web and live thereon in companies, and do not separate until about to prepare for the chrysalis state.
The chrysalis. The dorsal half of the head and wing points are black, and the ventral half orange. Some of the points on the body are tipped with orange. The whole surface is finely and irregularly furrowed and granulated. The ground colour is pale buff, covered with fine fuscous reticulations. The entire surface is clothed with a whitish-powdery substance, giving a pale lilac or pinkish bloom to the chrysalis, which, however, is easily rubbed off, the chrysalis then assuming a brownish hue. Our figure of the chrysalis is after Holland.
Mr. Frohawk, who had female butterflies living under observation for about three months, states that eggs were laid in April, May, and June. Caterpillars from the first batch of 192 eggs hatched early in May, nineteen days after they were laid. These were full grown by June 20, and entered the chrysalis state soon after. The butterflies from these commenced to emerge about the middle of July.
He says: “Both sallow and willow are equally suitable food for the larvæ, and birch is readily eaten, even when willow has formed the sole food until the last stage; they will feed on elm. Nettle was not appreciated, and not touched by them during the last two or three stages.”
This butterfly appears to have first attracted the attention of the earlier British entomologists about the middle of the eighteenth century. Stephens, writing in 1827, remarks that “about sixty years since it appeared in such prodigious numbers throughout the kingdom, that the entomologists of that day gave it the appellation of the Grand Surprise.” Harris figured the butterfly under the name mentioned by Stephens, and it has also been referred to by others as the “Willow Beauty” and the “White Petticoat.” Newman called it the “White-bordered;” and from this, as well as from his description of the butterfly, it would seem that he had not seen any specimen, caught in Britain, with ochreous borders. Such specimens have most certainly been captured in these islands, and occasionally in some numbers, as, for example, in the autumns of 1872 and 1880. In the former year the butterflies were seen or taken in a great many parts of the kingdom. The single specimens that are taken now and then in the spring have hibernated, and possibly they may have just come over from the Continent. It is, however, equally possible that they may have arrived in the country the previous autumn and passed the winter here. After the invasion in the autumn of 1872, specimens were observed in January, March, and April, 1873, at places widely apart. In 1881 single specimens were taken in April in Surrey, Kent, and Brecknockshire; and in Essex and at Hampstead in August. One or two specimens were taken in the summer or autumn of the years 1884 to 1887 inclusive. In 1888 two were captured in Essex in May; and in August, three in Kent, one each Surrey, Hants, and Isle of Wight; and one in Kent in September. In 1889 a specimen was taken in Surrey in April, one in Kent, and one in Cambs in May; a few also in the autumn of that year. In 1891 a specimen was seen at Balham in September. In 1893 one was taken in Epping Forest in April, and one in South Devon in August. Single specimens were noted in Oxfordshire, Lincolnshire, Berwick, and the Isle of Skye, in September, 1896, and one at Epsom in December of that year. In 1897 one was recorded from Yorks (August), and one from Norfolk (September); and in May, 1898, one was taken at Norwich. One or two were observed in August or September, 1898 and 1899; and in 1900 there seems to have been an invasion, on a small scale, of this butterfly in August into some of the eastern and southern counties of England. It extended westward to Somersetshire, and northward to Roxburghshire. A few were taken in various southern localities, including south-east and north London, in August and September of 1901. A specimen occurred in the Isle of Wight in September, 1903, and one in September, 1904; and in the latter year one was captured in August at Raynes Park in Surrey. In 1905 one butterfly was taken at Harrow, Middlesex, on July 27; one at Norwich on August 26, and one in Suffolk on September 29.
A full record of this fine butterfly in the British Islands would occupy too much space, but the details given above will show something of its erratic occurrence since 1880. It visits Ireland occasionally, but there are no recent reports of its having been seen there.
Kane, in his Catalogue of the Lepidoptera of Ireland, mentions a specimen taken in Co. Kerry, July 21, 1865; one from near Belfast [in 1875?]; and a third example seen by a friend “many years ago” near Trillick, Co. Tyrone. The latter was “settled on the roadside, but not captured, it being Sunday.”
Distributed throughout the temperate parts of the Northern Hemisphere, it is common in the Scandinavian Peninsula, whence probably our specimens came; also in Germany. In some parts of the Continent it is, however, almost as uncertain in its occurrence as in England.