Larger ImagePl.24.Clouded Yellow.1Female aberration; 2, 3, 4var. helice.
Pl.24.Clouded Yellow.1Female aberration; 2, 3, 4var. helice.
Pl.24.
Clouded Yellow.
1Female aberration; 2, 3, 4var. helice.
Pl.25.Brimstone Butterfly.Egg, natural size and enlarged; caterpillar and chrysalis.
Pl.25.Brimstone Butterfly.Egg, natural size and enlarged; caterpillar and chrysalis.
Pl.25.
Brimstone Butterfly.
Egg, natural size and enlarged; caterpillar and chrysalis.
The egg (Plate28) may be looked for in August on the upper surface of a leaf of the sallow (Salix caprea). According to Buckler, it is pale olive green in colour, and cylindrical in shape; the height from base to top being about equal to the width through from side to side. It has about fourteen ribs.
The caterpillar in October, just before hibernation, is dingy green roughened with numerous whitish warts from which arise short bristles, some of the latter appearing to be tinged with reddish, and those along the sides longer than those on the upper part of the body; the straight lines along the back and the oblique ones on the sides are yellowish. The head and the two horn-like projections, reminding one of the horns of a slug, are reddish-grey and covered with warts and bristles. The anal points (tails), which lie close together, are tipped with reddish. It should be mentioned here that on emerging from the egg the young caterpillar is without horns; these are not developed until the first skin is thrown off, which event happens from eight to twelve days after hatching.
The full-grown caterpillar is green, merging into yellowish towards the anal points (tails); the oblique stripes on the sides are yellowish, edged with reddish. The individual depicted on the plate took up a position for change to the chrysalis on June 6. It spun a mat of silk to the under side of a sallow leaf, and the next day it was found suspended by the claspers, which were grasping the silken mat. On the fourth day the chrysalis was fully developed, and from this a male butterfly emerged on June 24, an unusually early date.
The chrysalis is whitish, more or less tinged with green, but having the oblique lines on the sides whitish; the veins of the wings also show up whitish.
The caterpillar was well known to entomologists in this country as far back as 1758, when, in May, four were obtained from sallow at Brentwood in Essex. It usually occurs on sallow, but an instance is recorded of it refusing to eat this plant; it would probably have starved if willow, upon which it fed up, had not been substituted. A full-grown caterpillar was on one occasion found at Raindene in Sussex on poplar, which is a well-known food of the species on the Continent. Now and then a full-grown caterpillar has been met with in October, and Buckler reared two in the autumn from the egg almost to the chrysalis stage, but they died before the change was effected.
As befits his rank, the Emperor has lofty habits, and after quitting the clump of sallow bushes, among which its transformations from egg to the perfect insect were effected, it resorts to the oak trees, around which it flies in July, and, when not so engaged, rests on a leaf of the higher branches. To capture the butterfly, when seen at such times, is not altogether an easy matter, as for the purpose the net must be affixed to the end of a pole about 14 or 15 feet in length. The insect's rather depraved taste for the juices of animal matter, in a somewhat advanced stage of decay, is a fact well known to the professional collector and others who have taken advantage of it to the monarch's destruction. This method of attracting a butterfly for the purpose of capture is, however, not exactly to be commended. It surely is a greater pleasure to show one's friends a single specimen that has been captured by dexterity with the net, than to exhibit fifty that were secured by a device which is not only unsavoury, but unsportsmanlike. The female, however, is not to be allured; she must be sought among the sallows, and when seen is not easy to net, as she skims away over the tops of the bushes and is difficult to follow.
Larger ImagePl.26.Brimstone Butterfly.1, 3male; 2, 4female.
Pl.26.Brimstone Butterfly.1, 3male; 2, 4female.
Pl.26.
Brimstone Butterfly.
1, 3male; 2, 4female.
Brimstone Butterfly.Underside (aberration).
Brimstone Butterfly.Underside (aberration).
Brimstone Butterfly.Underside (aberration).
Pl.27.Common Blue.At rest.
Pl.27.Common Blue.At rest.
Pl.27.
Common Blue.At rest.
Although most certainly not so common or so generally distributed as in former times, the butterfly still occurs in the larger oak woods in most of the midland, western, and southern counties of England, but is, perhaps, most frequent in Lincolnshire and Northamptonshire. In Wales it is found in Monmouthshire. It has not been recorded from Scotland, and only doubtfully from Ireland.
In Central Europe it is often abundant, and its range extends eastward into Amurland, Central and Western China.
Now follow seventeen butterflies of the sub-family Nymphalinæ.
The "White Admirable Butterfly," as it was called by some of the older English entomologists, needs only to be seen to be at once recognized (Plate33). The white markings on its blackish wings are somewhat similar to those of the Purple Emperor. As in that butterfly, so, too, in this, the most beautiful ornamentation is found on the under side. The shape of the wing is, however, very different in the two butterflies, and there is no probability of confusing one with the other. A somewhat uncommon form is shown on Plate31(also kindly loaned by Mr. Sabine); this is var.nigrina. Intermediates also occur, but these, too, are also rather rare. The eggs, which I have not seen, are stated to hatch in about fourteen days, and are laid in July. They have been described as pale green in colour, and of the shape of an orange, but flatter at the base and top.
The caterpillar (Plate30) when full grown is dark green on the back and lighter on the sides, roughened with yellow dots, and with a yellow-marked white line above the feet. The bristly spines are reddish with pinkish tips, and those on the second, third, fifth, tenth, and eleventh rings are longer thanthe others. The first ring seems to be without spines, but the brownish head is set with short ones, two on the crown being rather longer and blacker than the others, and are inclined backwards.
In the autumn, when still quite tiny, it constructs a winter retreat (hibernaculum) (Plate30) by fastening a growing leaf of sallow to a twig with silken threads, and then, using more silk, it draws the edges of the leaf together, and so forms a secure chamber wherein it can rest until the following spring, when it quits the domicile and sets to work on the tender foliage around it. At this time the caterpillar is brownish in colour. The chrysalis is of the remarkable shape shown on the plate. It is brownish, with purplish or olive tinge; behind the rounded hump there is a patch of bright green, and above the wing-cases a beautiful golden sheen. There are also other metallic spots and dots on various parts. Altogether, it is one of the prettiest of British butterfly chrysalids.
I am tempted here to quote Buckler's excellent description of the pupation of this species, as it will serve to show the remarkable method by which caterpillars are able to perform a seemingly impossible feat; that is, to get absolutely free of the old skin whilst hanging head downwards from the silken pad or button to which they attach themselves by the anal claspers when preparing to pupate.
Pl.28.Purple Emperor.Egg enlarged; young and full-grown caterpillars; chrysalis.
Pl.28.Purple Emperor.Egg enlarged; young and full-grown caterpillars; chrysalis.
Pl.28.
Purple Emperor.
Egg enlarged; young and full-grown caterpillars; chrysalis.
Larger ImagePl.29.Purple Emperor.1male; 2female.
Pl.29.Purple Emperor.1male; 2female.
Pl.29.
Purple Emperor.
1male; 2female.
"When full fed the larva becomes rapidly paler, and then suspends itself by the anal prolegs to a stem of the honeysuckle or other surface, and hangs with its body downwards in a sinuous curve, with its head bent a little upwards, facing the abdomen; it then remains motionless for three days, becoming whitish on the abdomen, and remaining very pale green on the thoracic segments. In the course of the third day the creature seems to wake up, unbends its head, swings itself to and fro a few times, then stretches itself downwards in a long attenuated line, which causes a rupture of the skin close to the head;the skin then is seen slowly to ascend, exposing the bare and soft shining parts below, from which a flat and forked pair of horns grow out perceptibly as one beholds this wonderful process; the skin continues to glide slowly upwards, and as the soft parts become exposed, they are seen to swell out laterally, and to assume the very singular projections so characteristic of this chrysalis, the skin of the old head gliding up the belly marks the progress of the disclosure, as the colour of the old and new surfaces is at this time alike, the new being, however, rather more shining and transparent. Occasionally during the bulging out of the soft parts, a kind of convulsive heave or two occurs, but otherwise it remains still until the creature is uncovered as far as the ninth or tenth segment; it then curves its anal extremity by a sudden twist laterally, and in a moment dexterously withdraws the tip of the anal segment from the larval prolegs by an opening on the back of the skin at that part. At this critical moment one has time to see that the naked shining point is furnished with black hooks, and to apprehend a fall; but in another moment the pupa has forcibly pressed the curved tip with its hooks against the stem close to the previous attachment of the anal prolegs, and now it is strongly and firmly fixed. The creature now seems endowed with wonderful power and vigour; it swings boldly to and fro, and undulates itself as if to gain longer swings, when presently the old skin that remains is seen to burst away and fall off, the chrysalis gradually becoming quiescent, the entire metamorphosis, from the first waking to the last movement, occupying nearly seven minutes. In sixteen days the perfect insect emerged."
Linnæus in 1767 wrote of the sexes of this butterfly assibylla, or rathersibilla, andcamilla, but, as Kirby points out, three years earlier the same author had given the butterfly the namecamilla. It is probable, therefore, that the latter name will have to be adopted for our butterfly. Certain it is thatthe older British authors—Donovan, Haworth, Stephens, etc., knew our species ascamilla. The species known on the Continent ascamilla, and which, owing to the confusion of names has been supposed to be British, will have to be calleddrusilla, according to Kirby.
This species seems to be pretty much restricted to the southern and eastern counties of England. In the New Forest, Hampshire, it is often exceedingly abundant in July. So long ago as 1695 the butterfly was known to occur in Essex, and the species is found in some woods in that county at the present time. It has, however, quite disappeared from several woodland localities in Kent and Sussex, where it formerly occurred. It has been recorded from Shropshire and also from Worcestershire, but both these counties appear to be beyond the normal range of the species.
Almost all writers on our butterflies, from Haworth downwards, have commented on the graceful flight of the White Admiral as it skims aloft and alow through the woodland glades. This elegance of motion is still retained even when the wings become sadly torn and frayed, probably by contact with twigs and thorns.
Widely distributed throughout Central Europe. It is also found in Amurland, Corea, and Japan.
The peculiar shape of the wings of this butterfly (Plate35) might cause it to be mistaken for a very tattered example of one of the Tortoiseshells. The irregular contour of the outer edges of the wings is, however, quite natural, and is subject to some variation in its jaggedness. Their colour is deep tawny or fulvous, with brownish borders on their outer margin. On the fore wings there are three black spots on the front or costal area, and below the first, which is often divided, there is aroundish black spot (sometimes double) just above the inner margin; two, sometimes three, other spots lie between this and the third costal spot. On the hind wings there are three black spots on the basal half, and a series of pale fulvous spots before the brownish border; these are inwardly edged with brownish, and sometimes this edging is united with the marginal border. Similar spots are, in some specimens, present in a like position on the fore wings also. On the under side the wings are of various shades of brown, sometimes variegated with whitish, or yellowish, and greenish, the latter often conspicuous; other specimens are paler on the outer half than on the basal half, and, except occasionally having a series of greenish or dusky spots on the outer area, are without marking. These differences occur in both sexes. The white comma or c mark, placed about the middle of the under side of the hind wings, is rather stronger in the variegated specimens; but it varies, generally, in shape as well as in size.
Pl.30.White Admiral.Young caterpillar with hibernaculum (h); caterpillar and chrysalis.
Pl.30.White Admiral.Young caterpillar with hibernaculum (h); caterpillar and chrysalis.
Pl.30.
White Admiral.
Young caterpillar with hibernaculum (h); caterpillar and chrysalis.
Larger ImagePl.31.1, 2 Purple Emperor; 3 var.iole.4, 5 White Admiral, var.nigrina.
Pl.31.1, 2 Purple Emperor; 3 var.iole.4, 5 White Admiral, var.nigrina.
Pl.31.
1, 2 Purple Emperor; 3 var.iole.
4, 5 White Admiral, var.nigrina.
Var.hutchinsoni, Robson, which has been renamedpallidaandlutescens, differs from the typical form in having the ground colour much lighter and brighter on the upper side and ochreous on the under side. It is shown on Plate35.The outline of the wings of this form, which occurs in June and July, is said to be less jagged, and this may be so as a rule, but it certainly is not always the case. Possibly this is "The Pale Comma" of Petiver.
There are two broods of this species in the year, but the first or summer flight of butterflies seems to depend upon a favourable season, as also does the second or autumnal brood, at least as regards the number of butterflies representing it. The late butterflies hibernate and reappear in April, or even March, of the following year. It has been stated that all the specimens appearing in the spring are of the form with plain under sides.
From eggs laid between April 27 and May 6, Miss E. Hutchinson, writing in 1887, says caterpillars hatched between5 and 11. They were "fed" on currant and nettle mixed, and were full grown from June 17th till the 23rd. The first butterfly emerged on June 26, and the last on July 3, and all were very fine and of the pale summer variety. Two of the insects paired on June 30, and the female commenced laying on July 1, and continued doing so till the 10th, when there were 120 ova. Unfortunately, a very cold spell of weather began on July 12, and more than half the eggs perished. The butterflies resulting from the remainder appeared during August, from the 17th to the 27th, but they would not pair, probably because, although they had emerged at an early date, they properly belonged to the autumnal flight.
In 1894 Mr. Frohawk reared 200 of these butterflies from 275 eggs laid by a female between April 17 and June 1 of that year. The caterpillars were supplied with nettle only. The first butterfly emerged on June 30, and the last on August 2. Of the whole number forty-one were of the light fulvous form, var.hutchinsoni, and all the others of the dark or typical form. With few exceptions, the light-coloured butterflies were the first to emerge, and the major portion of these during early July, and before any examples of the dark form had come out.
The egg is at first green in colour with ribs whiter, but changes before the caterpillar hatches out to yellowish. In confinement the female butterflies deposit their eggs singly or in chains of three or four; probably the latter is the usual method of laying the eggs under natural conditions.
The caterpillar when full grown is black, netted with greyish; the spines on the second to fifth rings inclusive are yellowish, and those on the back of the other rings are white; the back from ring 6 to ring 10 inclusive is broadly white, marked with black, and the upper surface of the other rings is more or less yellowish. The head is black, marked with ochreous; the crown is lobed, and on each lobe is a short club-like knob.
Pl.32.Comma Butterfly.Egg enlarged; caterpillar and chrysalis.
Pl.32.Comma Butterfly.Egg enlarged; caterpillar and chrysalis.
Pl.32.
Comma Butterfly.
Egg enlarged; caterpillar and chrysalis.
Larger ImagePl.33.White Admiral.1, 3male; 2, 4female.
Pl.33.White Admiral.1, 3male; 2, 4female.
Pl.33.
White Admiral.
1, 3male; 2, 4female.
The chrysalis is brownish tinged with pink; the wing-cases and the rings of the body are edged with blackish; there is a greyish line along the back of the body and a brownish stripe along the spiracles; at the point where the body joins the thorax there are some silvery or golden spots. The figures of caterpillar and chrysalis on Plate32are after Buckler.
This butterfly seems to have disappeared from many localities in England where it formerly flourished. About seventy or eighty years ago, for example, it was plentiful in Epping Forest, in Herts, and in Dorset. During the last half-century or so it has been common in certain parts of many of the counties from Somerset to Durham and Cumberland, but seems to have occurred only sparingly or singly in Norfolk, Suffolk, Essex, Kent, Sussex, Hants, Wilts, and Devon. It still occurs now and then in the Dover district, the most recent record being of one taken in October, 1894; and it was reported from North Staffordshire in 1893. Probably it is now almost entirely confined to favoured districts embraced within the area represented by the counties of Herefordshire, Worcestershire, and Monmouthshire, whence it may occasionally stray into the adjoining counties, or even further afield.
This butterfly is often associated with hop gardens, but it is by no means restricted to such places. The usual food-plants of the caterpillars are hop (Humulus lupulus), nettle (Urtica dioica), and currant (Ribes), but it is reported to eat gooseberry (R. grossularia) and elm (Ulmus).
Abroad it has a very wide distribution in Europe, and extends through Asia to Japan.
Apart from its larger size, and somewhat different outline, this butterfly may be known from the Small Tortoiseshell by its duller colour, which is brownish-orange; on the fore wingthere are, as a rule, no blue crescents in the hind marginal border, but there is an extra black spot placed between veins 1 and 2; on the hind wings a black spot on the front area represents the black basal area seen on the Small Tortoiseshell; and this is an important point of difference, although the two species are not likely to be confused when both are well known. The blue spots referred to as not usually present on the fore wings are stated to occur in specimens emerging from chrysalids that have been kept in a rather cold temperature for a certain length of time.
An aberration known astestudohas the black spots of the fore wings united, and forming blotches on the front and inner areas; the ground colour of the fore wings is lighter, and the hind wings are blacker. This form occurs at large on the Continent, but it is rare; it has also been produced in the course of temperature experiments.
The only eggs of this butterfly that I have been able to obtain are the batch figured on Plate34.These were purplish with whitish ribs, but no caterpillars hatched from them. Hellins, who squeezed a few eggs from a freshly killed female, states that the colour apparently is a dull green. The ribs vary from seven to nine in number.
The caterpillar in the adult stage is black, with a speckled dark ochreous band traversed by a black central line on the back; the sides are dappled with ochreous grey; the under parts are brown dappled with darker, and merging into the black. The spines are dark ochreous tipped with black, and the head is shiny black and bristly. (The figure is after Buckler.)
These caterpillars live in large companies, often at the top of a high elm tree, from which they may be dislodged by a well-aimed stick, if this happens to be heavy enough to jar the branch when it reaches the mark. Besides elm trees (Ulmus), they also may be found on willow and sallow (Salix), aspen and poplar (Populus), white-beam (Pyrus aria), and variousfruit trees, especially cherry. Occasionally they have been found on nettle, but the butterflies from these were small in size. June is the best month for them.
Pl.34.Large Tortoiseshell.Eggs, natural size and enlarged; caterpillar and chrysalis.
Pl.34.Large Tortoiseshell.Eggs, natural size and enlarged; caterpillar and chrysalis.
Pl.34.
Large Tortoiseshell.
Eggs, natural size and enlarged; caterpillar and chrysalis.
Larger ImagePl.35.Comma Butterfly.1, 2, 3, 4, 5, 6male; 7female(var.hutchinsoni).
Pl.35.Comma Butterfly.1, 2, 3, 4, 5, 6male; 7female(var.hutchinsoni).
Pl.35.
Comma Butterfly.
1, 2, 3, 4, 5, 6male; 7female(var.hutchinsoni).
The chrysalis (Plate34) is greyish, tinged with pink or reddish, sprinkled with greenish, and shaded with brown and black; the back of the body nearest the thorax is adorned with golden spots. I once obtained a number of these chrysalids in July at Mill Hill; they were found suspended by the tail from the edges of boards that formed a rickety old cart-shed standing at one end of a field and beneath an elm tree.
Although this butterfly is often common in the caterpillar state, the perfect insect, which emerges in July and August, is more frequently seen in the spring after hibernation than before that event. It probably establishes itself in suitable quarters, in old trees, faggot stacks, barns, etc., for its long rest during the winter, at an early period after emerging from the chrysalis.
No doubt large numbers are destroyed by their great enemies, the parasitic flies, chiefly perhaps the HymenopterousApanteles. An observer states that from fifty chrysalids only one butterfly resulted, all the others were found to be filled with parasites. In another case of one hundred caterpillars, some collected when quite small, only one was not "ichneumoned."
These butterflies, in common with most other Vanessids, do not pair until the spring, but Barrett cites an instance of caterpillars, from eggs laid by a female in early September, being reared until about 1/2 inch in length, when they apparently laid up for hibernation.
Lanes margined with trees, especially elms, or the verges of woods, are the most likely places in which to find the butterfly. At one time and another it has been observed in nearly every county of England and Wales, and also in some parts of Scotland, but not in Ireland. It appears to be more or less common in all counties around London, extending toSomerset in the west; to Cambs, Norfolk, and Suffolk in the east; and to Northampton and Warwick in the Midlands.
Abroad it is found throughout the greater part of Europe, Asia Minor, and eastward to the Himalayas.
This butterfly is one of the most ubiquitous as well as prettiest that we have in this country. Its reddish-orange colour, marked with yellow patches, black spots, and blue crescents, gives it a charming appearance as it sits on a flower, or even on the ground, with wings fully expanded to the sunlight. When the wings are closed up, however, the butterfly seems to disappear, as the under side of the wings is quite sombre in colour. The only bright spot on the under side is the yellowish central area of the fore wing, and when the wings are held erect over the insect's back this is not seen, but only the tips of these wings, which are of the same dull colour as the hind wings.
Fig. 22.
Fig. 22.
Fig. 22.
The ground colour is subject to modification as regards the shade of red in the orange, and this may be intense or reduced to just a mere tinge. Specimens have been taken on the wing in which the colour was some shade of buff, and the same kind of colour change will sometimes result from an over-longexposure to the action of ammonia. The black markings vary in size, and sometimes those on the costal area are more or less connected or even confluent (Fig.22); a greater or lesser amount of blackish suffusion on the hind wings (Fig.23) generally accompanies confluence of the costal spots on fore wings. The two black spots between veins 2 and 4 occasionally enlarge and unite, or, on the other hand, they decrease in size to vanishing point. Some specimens have black scales between the second costal spot and the black spot on the inner margin, and the space between these two spots may be entirely covered with black and so form a central transverse band (var.polaris). A modification of this form is shown on Plate38,lower figure. The yellow patch between the second and third costal black spots is sometimes continued right across the wings to the yellow spot on the inner margin, and in this respect resembles an Indian form of the species namedladakensis. Dwarf specimens result, in most cases, when the caterpillars have fed on hop (Humulus); at least, this is so in confinement.
Fig. 23.
Fig. 23.
Fig. 23.
The egg is at first green, but after a time becomes tinted with yellow and the ribs stand out clear and transparent. The eggs are laid in a cluster on the under side of a terminal leaf of a nettle plant in May and again in July.
The adult caterpillar is yellowish, closely covered with black speckling and short hairs; there is a black line down the centre of the back, and this is bordered on each side by the clear ground colour. The spiracles are black ringed with yellow, and there is a yellowish line above them. The yellowish spines have black tips. Head black, hairy, and speckled with yellow. Individuals of another company were almost entirely black, the spines alone being tinged with yellow. These caterpillars are gregarious from the time they hatch from the egg until about the last stage.
The chrysalis is most often of some shade of grey and sometimes tinged with pinkish. The points on the upper parts of the body are in some examples metallic at the base, and occasionally the metallic lustre spreads over the thorax and other parts as well.
There are two broods in the year, one in June, the other in August and September. The latter brood, or at least some of the butterflies, hibernate and reappear in the earliest sunny days of spring. They have been seen on the wing as early as January and February (1896), and as late as December.
The geographical range of this species extends through Europe and Asia to Japan.
Unlike the last species referred to, this handsome butterfly is more frequently seen in the autumn than after hibernation. It is not likely to be mistaken for any other kind, for on its brownish-red velvety wings it bears its own particular badge, the "peacock eyes." The marks on the hind wings are more like the "eyes" on the tail feathers of the peacock than are those on the fore wings, and the brownish-red on these wings is confined to a large patch below the eye-mark, the remainder being blackish, powdered with yellow scales on thebasal area. Some specimens have a blue spot below the "eye" on the hind wings, and the namecyanostictahas been proposed for this form by Raynor. The under side is blackish, with a steely sheen, and crossed by irregular black lines; the forewingsare tinged with brown on the inner area, and the central dot and a series of dots beyond are ochreous; the hind wings have an ochreous central dot.
Larger ImagePl.36.Large Tortoiseshell.1, 3male; 2, 4female.
Pl.36.Large Tortoiseshell.1, 3male; 2, 4female.
Pl.36.
Large Tortoiseshell.
1, 3male; 2, 4female.
Pl.37.Small Tortoiseshell.Eggs enlarged; caterpillar and chrysalis.
Pl.37.Small Tortoiseshell.Eggs enlarged; caterpillar and chrysalis.
Pl.37.
Small Tortoiseshell.
Eggs enlarged; caterpillar and chrysalis.
In a state of nature the butterfly seems little given to variation. In rearing from the caterpillar, however, some curious aberrations occasionally crop up. In my early days of collecting I raised a number of specimens from caterpillars selected from a large brood; every one of these butterflies was of a dull brownish colour and had a greasy semi-transparent appearance. I regret to add that I set them all at liberty as they did not come up to my, then, standard of what a Peacock butterfly should be. Now and then specimens are bred from collected caterpillars, in which the eye spots are represented by a broad white cloud-like suffusion on the fore wings, and by a pale roundish patch on the hind wings; in conjunction with this the black costal spots of the fore wings are all more or less united (see Plate41). This extreme variety is known in the vernacular as the "Blind Peacock," and asab. belisariain science; between it and the typical form there are all kinds of intermediate modifications, and one of these is also shown on the plate referred to. It may be interesting to remark that similar varieties have been produced by subjecting the chrysalids at a particular period to a very low temperature. Readers who may wish to know more about "Temperature Experiments" are referred to a pamphlet on the subject by Dr. Max Standfuss.
The egg, an enlarged figure of which will be found on Plate39,is olive green in colour, and has eight ribs, which start just above the base and turn over the top. The eggs are laid in April or May in batches on the upper part of nettle plants and under the young leaves.
The mature caterpillar is velvety black with white dots, and the divisions between the rings of the body are well marked. The spines are black and rather glossy, and besides this clothing, the body is also provided with short hair which gives the velvety appearance. The head and a plate on the next ring, also the legs, are shining black; the prolegs are blackish, tipped with yellowish. When quite young they are greenish-grey, and although hairy are without spines. The caterpillars usually feed in companies in June and July on the common stinging nettle. They have also been found on hop. Once or twice I have reared caterpillars of this butterfly, and also those of the Small Tortoiseshell and the Red Admiral, on hop, but the result has been disappointing, as the specimens produced were always small in size. The individuals for these experiments were obtained from nettle, and were generally about half grown at the time they were put on the hop diet.
The chrysalis is figured on Plate39.Its colour may be pale greenish, greyish, pale brown, or brownish-grey, but is usually stippled with blackish, especially the antennæ and the outline of the wing-cases. Some of the points on the thorax and the ring, or rings, next to it have a metallic lustre. Two chrysalids among those resulting from my hop-fed caterpillars were more or less suffused with the metallic sheen. It does not seem to be very clearly known where the caterpillars retire to for pupation. Those that I have found have been under a tent-like arrangement of the lower nettle leaves. In confinement, however, I have noted that in a roomy cage they all go to one end of it and suspend themselves from the roof; in a large flower-pot they crowd together in much the same way.
The butterfly is on the wing in August and September, and frequents all and every kind of ground where flowering plants, especially the taller kinds, are available; clover fields are attractive, and so also are orchards. It passes the winter in some hollow tree trunk, wood stack, or possibly buildings ofsome kind, and in the spring it again comes forth. March and April are the usual months for its reappearance, but in 1900 it was seen flying over the snow on February 17. The time last mentioned is probably an unusual one, but it is interesting to note that a very similar observation was made by Harris, who in 1778 wrote in his remarks on this butterfly, "I have seen them flying in February, when the snow has been on the ground."
Larger ImagePl.38.Small Tortoiseshell.1, 2female; 3, 5male; 4var.
Pl.38.Small Tortoiseshell.1, 2female; 3, 5male; 4var.
Pl.38.
Small Tortoiseshell.
1, 2female; 3, 5male; 4var.
Pl.39.Peacock Butterfly.Egg enlarged; caterpillar and chrysalis.
Pl.39.Peacock Butterfly.Egg enlarged; caterpillar and chrysalis.
Pl.39.
Peacock Butterfly.
Egg enlarged; caterpillar and chrysalis.
Usually the Peacock butterfly assumes the perfect state but once in the year. There is, however, a record of half-grown caterpillars being found in September, and that these produced butterflies in due course.
Although not always abundant, the butterfly is to be, or has been, found in almost every part of the kingdom, excepting perhaps north of the Caledonian Canal in Scotland. Around Bishop Auckland and in other parts of the county of Durham, and also in Northumberland, it was common some forty years ago, but it seems to be hardly ever seen there now. The same applies to other northern localities where it was once plentiful. Its distribution includes the whole of Europe, Asia Minor, Siberia, Amurland, Corea, and Japan.
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.hygiæaor var.lintneri(Plate41); 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 producedby 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 Plate43,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 theEntomologistfor 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 emittinga 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.
Larger ImagePl.40.Peacock Butterfly.1, 3male; 2, 4female.
Pl.40.Peacock Butterfly.1, 3male; 2, 4female.
Pl.40.
Peacock Butterfly.
1, 3male; 2, 4female.
Pl.41.1, 3 Peacock vars.; 2 Camberwell Beauty var.
Pl.41.1, 3 Peacock vars.; 2 Camberwell Beauty var.
Pl.41.
1, 3 Peacock vars.; 2 Camberwell Beauty var.
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 EppingForest 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.