 
THE MOTHSOF THEBRITISH ISLESBYRICHARD SOUTH, F.E.S.AUTHOR OF |
| Pl. 2. |
| Lime Hawk-moth. |
| Caterpillar and chrysalis. |
| Pl. 3. |
| Lime Hawk-moth. |
The figure of a nearly full-grown caterpillar (Plate 2) is from a drawing in colour by Mr. A. Sich. Shortly, the caterpillar may be described as green, roughened with yellow points, and with seven yellow oblique stripes on the sides, each edged above with purplish and reddish; the spiracles are ringed with reddish, and the curved horn is blue, inclining to yellowish beneath and at the tip; the roughened shield on the last ring of the body is reddish, marked with yellow. Head triangular, smoother than the body. Quite in its infancy, the caterpillar is a long, thin creature; the horn, which is divided at the tip, is covered with short, stiff hairs, and appears blackish; later on the horn becomes reddish, and the side stripes appear on the body. Although alder, birch, and several other shrubs and trees have been mentioned, there is no doubt that the foliage of elm and lime is the chief food of the caterpillar in a state of nature. Found in July and August.
The chrysalis is dark reddish, and somewhat rough. As a rule, it is enclosed in a very fragile cell which the caterpillar makes for itself after burrowing a few inches underground and near the trunk of an elm or a lime tree. There are, however, records of the chrysalis having been found in crevices of bark high up on elm trees.
In May and June the moth emerges, usually in the afternoon, and may sometimes be found on the trunks of trees, or on palings near limes and elms. When at rest the fore wings are so arranged over the hind ones that they, in conjunction with the upturned body, give the insect more the appearance of a bunch of immature leaves than of a moth.
The species is widely distributed throughout the southern counties of England, and in some of them, more especially around London, it is common. In the Midlands it seems to be scarce, and apparently does not occur further north than Yorkshire, from which county there is only a single record. It is common in Europe, except in the more northern and southern parts, and its range extends eastwards into Siberia.
The Poplar Hawk-moth (Smerinthus (Amorpha) populi).
On Plate 5 are three slightly different examples of this moth. In colour it is most frequently ashy grey, with a brownish central band, and other markings; there is a white spot on the fore wings and a conspicuous red patch at the base of the hind wings. The female is generally paler than the male, and often has a pinkish tinge. Specimens of a pale buff colour are sometimes obtained, and these are most often of the female sex, although male examples of this form are not unknown. Among unusual aberrations is one described as having the wings, legs, thorax, and abdomen of a colour between brick-red and chocolate, suffused with a whitish bloom as on ripe plums. Another had the hind wings unadorned with red. Specimens from Aberdeenshire and Sutherlandshire are smaller than English examples, and the males are almost always more brightly and distinctly marked.
A very large number of Gynandrous, or "hermaphrodite" specimens have been recorded, several of them from Britain; in most of these the gynandromorphism is bilateral, that is the insect is wholly male on one side, and entirely female on the other. In some the right side is male, in others the left side; the opposite side in each case being female. Much information on this subject and on Hybridism of the SphingidÆ will be found in Tutt's "British Lepidoptera," vol. iii.
The pale shining green eggs are laid, generally singly, but sometimes in twos, threes, or more, on either surface of a leaf of poplar or sallow. Now and then batches of eggs may be found, and these have probably been laid by females that were crippled on emergence, or had been afterwards injured in some way and so were unable to fly.
| Pl. 4. |
| Poplar Hawk-moth. |
| Eggs, natural size and enlarged; caterpillar and chrysalis. |
| Pl. 5. |
| Poplar Hawk-moth. |
When full grown the caterpillar is green, roughened with yellow points, oblique stripes on the sides yellow, spiracles reddish, horn of the general colour, sometimes tipped with reddish. Head triangular in shape, but not pointed on the top. A reddish spotted form of the caterpillar is not very uncommon. In its very early life the head is rather triangular than rounded, as is the head of the young caterpillar of the previous species, and also that of the Eyed Hawk. Feeds on poplar, aspen, sallow, and willow, and may be found from July to September and sometimes October. Chrysalis blackish, rougher than that of the Lime Hawk. It lies in the ground so close to the surface that it is often exposed when the garden borders under or near poplars are raked over. The moth appears in May and June as a rule, but in backward seasons it may not emerge until July or even August. Caterpillars from eggs laid in early May are likely to feed up and attain the perfect state in late July, and eggs resulting from these will pass through the caterpillar state to that of chrysalis by about September. Three broods have been obtained in one year, but this is exceptional and under a forcing method of treatment. The early stages are figured on Plate 4. This is certainly the commonest of our Hawk-moths, and it seems to occur throughout our islands, except that in Scotland it is not recorded further north than Sutherland and Ross. Wherever there are poplars, sallows, or willows, there too most probably will be this caterpillar in its season; the moth also will be almost certainly seen by any one who may care to keep an eye on the stems of poplars or adjacent fences at the right time. Sometimes the insect will introduce itself to the household, after lighting-up time, much to the alarm of those who, not aware of the harmless character of their visitor, look upon it with considerable suspicion.
Distribution abroad—Europe (except the polar regions and Greece), Armenia and the Altai.
The Eyed Hawk-moth (Smerinthus ocellatus).
Except that there is sometimes an absence of rosy tinge on the fore wings, and that the brownish markings may be lighter or darker, this species does not depart very greatly from the typical form shown on Plate 7.
Cross pairings between the Eyed-hawk and the Poplar-hawk are not altogether difficult to obtain, but the female populi pairs more readily with male ocellatus than the female of the last named species will with the male of populi. Very few such cross pairings have been noted in a wild state, but several cases of the kind are known to have occurred in captivity. The results are hybrid moths, and these have some of the characters of each parent, and have received distinctive names. Thus the offspring of ocellatus ♂ × populi ♀ are the hybridus, Steph., whilst that of populi ♂ × ocellatus ♀ are referable to inversa, Tutt.
| Pl. 6. |
| Eyed Hawk-moth. |
| Eggs, natural size and enlarged; caterpillars and chrysalis. |
| Pl. 7. |
| Eyed Hawk-moth. |
The eggs, which are generally laid singly or in pairs on either side of a leaf, sometimes on a stalk, are yellowish-green in colour. The shell is said to be netted, but under a fairly strong lens this does not show. About four hundred is probably the average number for a female to lay in a state of nature, but they seem not to deposit so many when reared from the egg in confinement. As the moth, except under stress of circumstances, places her eggs on the foliage of trees and bushes in selected positions, the business of egg laying takes about six nights to perform. Even when she is unable to fly she will crawl from twig to twig and glue an egg here and there on the leaves, but rarely more than two on a leaf. On a small sallow bush in my garden, I once counted eighty-four eggs on the lower leaves and the main stem. Green, inclining to yellowish or greyish, is the colour of the full-grown caterpillar. It is roughened with white points, and has seven whitish oblique stripes on the sides. These stripes are edged in front with darkish green and occasionally tinged with violet. The horn is bluish, merging into green towards the dark tip, and roughened with white points. Head triangular in shape, the top pointed; face tinged with bluish. Sometimes bright red spots appear on the sides in some examples of the caterpillar. In the quite young stage the head is usually rounded; the horn, which appears reddish, is about one third the length of the caterpillar.
Sallow, willow, and apple are the more general food plants, but poplar and privet have been reported. I have sometimes found the larva on Salix repens, and also on crab-apple (Pyrus malus). It may be found in July and August. In some years, when the moths emerge in May, caterpillars are found as early as June, and this is followed by the occurrence of the caterpillar again, as a second brood, in August and September. When quite mature the caterpillar enters an inch or two into the soil, and there forms a weak sort of cell in which it shortly afterwards turns to a brown, or blackish-brown, smooth and rather glossy chrysalis. The early stages are figured on Plate 6.
The moth usually emerges in June, earlier or later, according to season. Under very favourable circumstances some of the moths will leave the chrysalis in May and give rise to a second generation in July. An unfavourable year, on the other hand, retards emergence, and the moths do not come up until late June or mid-July; such has been the case this year (1907).
Generally distributed and by no means uncommon throughout the southern half of England, but somewhat local northwards. It has been recorded from the most southern counties of Scotland, and Kane states that in Ireland it is widely distributed but usually scarce.
The method of folding down its wings in repose is very similar to that of the previous two species.
The Death's-head Hawk Moth (Acherontia (Manduca) atropos).
The fine moth represented on Plate 8 is the largest species found in the British Isles, although in measurement from tip to tip when the wings are expanded it does not exceed that of the next species, both varying in this respect from 4½ to 5 inches. It is, however, a stouter bodied insect, and its wings are broader. The colour and markings are so well shown in the illustration that a description is unnecessary. Beyond a greater or lesser intensity of the paler markings on the fore wings and the thorax, also some modifications in the black band of the hind wings, there is nothing very striking in the way of variation. Perhaps the most important aberrations are connected with the inner black band of the hind wings, which may be much widened and diffuse, or, on the other hand, entirely absent.
When full grown, the caterpillar attains a length of nearly 5 inches, and is of considerable thickness throughout. Usually the general colour is some shade of green, varying to yellowish, but in some examples it is brown, more or less tinged with violet; others again are of a blackish hue. The seven oblique side stripes are purplish or violet brown, edged with yellowish; they are absent from the three rings nearest the head; the rough, double curved horn is of the body colour. The greenish forms are sprinkled with violet dots, and the brownish forms with white ones. Most frequently found on the leaves of potato; it feeds also on the "tea-tree" (Lycium barbarum), woody nightshade (Solanum dulcamara), and snowberry (Symphoricarpus). Fig. 1, Plate 9, represents the brown form of the caterpillar.
When ready to enter the chrysalis state, the caterpillar burrows from 2 to 4 inches below the surface of the soil, and there forms a large chamber, the walls of which are not very substantial and are easily broken. After resting therein for a week, or two, it turns to a dark brownish, rather glossy, chrysalis. (Plate 11, Fig. 1). The earthen cocoon, frail as it is, seems to be a protection to the chrysalis, guarding it from too much moisture on the one hand, or dryness on the other. I always found that when chrysalids from caterpillars that I have obtained were left undisturbed the moths emerged well enough; but when they were turned up out of the ground by the potato diggers, and, of course, without covering, they were almost certain to perish if the attempt were made to keep them through the winter. In the latter case, the only chance was to endeavour to induce the moth to emerge as soon as possible by bringing them under the combined influence of warmth and moisture.
This species was known to Mouffett, who figured it in 1634, but it does not appear to have received an English name until 1773, when Wilkes figured it as the "Jasmine Hawk Moth." Moses Harris, in 1775, called it the "Bee Tyger Hawk Moth," but three years later he changed the name to the Death's Head, the name by which it is still known, although in some parts of England, as well as in Ireland, it is referred to as the "bee robber." In connection with the latter name, it may be mentioned that the moth's "tongue," or proboscis, is short, and not adapted for obtaining sweets, of which it is very fond, from long-tubed flowers, consequently it filches honey from the bees, and, with this object, has been known to enter bee-hives, at least those of the old straw-skep pattern. The moth is also said to have a liking for the sap exuded by wounded trees. Although the species may, perhaps, be with us in certain favoured localities every year, it does not often occur, in any stage, in numbers sufficient to attract general attention. I have not searched the chronicles of Atropos in Britain earlier than 1864, but from these it seems that the species was widely distributed and generally common in 1865, 1868, 1878, 1885, 1896, and 1900. More or less common in certain localities in 1867, 1869, 1870-1872, 1877, 1880, 1882, 1884, 1893, 1895, 1899, 1911, and 1917. In the other years it was scarce, or apparently absent.
The moth is always very much less in evidence than the caterpillar, or even the chrysalis. Sometimes the former is seen in May or June, or even earlier, and it has been supposed that these precocious specimens have hibernated after emergence from the chrysalis here during the previous autumn. The question of hibernation need not be entertained, but there may be doubt as to whether the specimens are British born or aliens. I am inclined to the latter view. The moths are often noted at sea long distances from land. A specimen was captured on board a vessel in the North Sea on April 28, 1903, and it was still alive, although it had been roughly dealt with, on May 8 of that year. In 1899 a moth was taken at Chester, about the middle of May, and one on June 20 at Chichester. Probably, although undetected, other specimens were also about the country, and maybe at even earlier dates than those recorded. However, during the year larvÆ and pupÆ were found, at the end of July, at Chilton, Suffolk, and at Bridgwater, Somerset, and in early August in Somerset, and at Dover. A moth was captured in August at Marlow, Bucks., one was taken at Christchurch on September 19, one at Reigate, September 25. Several specimens occurred in Devon and Cornwall in the autumn, and at Deal early in October. LarvÆ were found, too, from the second week in September to the end of that month in several parts of the country. Moths seem to have been reared in early September from the early August caterpillars; whilst the September caterpillars attained the perfect state towards the end of the month and in October. Two pupÆ, found at Penarth on September 12, produced moths in from four to six days afterwards; four other chrysalids, obtained in Hants about mid September, yielded moths between September 21 and the beginning of October.
| Pl. 8. |
| Death's-head Hawk Moth. |
| Pl. 9. |
| 1. Death's-head Hawk-moth. |
| Eggs, natural size and enlarged; and caterpillar. |
| 2. Convolvulus Hawk-moth Caterpillar (dark form). |
From the foregoing there can be no question that there are at least two generations of the moth in some years, and in our own country, but we have even clearer evidence of this in the records of 1900, when a moth was taken in the spring at Ayton, Berwickshire, another at Worsborough Bridge on June 18, and a third at Kilmarnock, on a bee-hive, July 11. Caterpillars were found during late July and August in South Scotland and various parts of England, and moths were reared from some of these. In September and October caterpillars were found more commonly, and two or three moths were captured, in various places, between August 19 and October 9; others, reared from September caterpillars, emerged from October 30 to November 24.
By the rustic, and possibly the uninitiated generally, the moth is looked upon as something uncanny. This is probably due to the fact that the creature, when handled, emits a peculiar sound that has been described as a shrill squeak. According to Kirby, the statement made by Rossi that the sound is produced by air from the air-sacs being forced through the proboscis, has been verified. Another dread-inspiring character of the insect is the marking on the thorax, which has been likened to a skull and crossbones. The squeak is said to have the effect of quieting the bees, they being under the impression that it proceeds from their queen.
It has been taken at some time or another in almost every part of the British Isles, right up to and including the Shetlands. Except that it has not been observed in the more northern parts, the species is found throughout Europe, North and South Africa, the Canary Islands, and the Azores. It is also represented in Southern India, extending to the Malays, and in China, Corea, and Japan.
Convolvulus Hawk-moth, Herse (Sphinx) convolvuli.
The older writers on British moths called this the "Unicorn" or "Bindweed Hawk." The fore wings are whitish grey, mottled with darker tints, and, in the male, clouded with blackish about the middle of the wing; the central third is limited inwardly by a double blackish, wavy line, and outwardly by an irregular, toothed, whitish line; running from one to the other are two black streaks between the veins, and a similar streak nearer the costa is waved upwards to the tip of the wing. The hind wings are whitish grey, with a black stripe near the base, and two blackish bands between the stripe and the outer margin. The thorax agrees in colour with the fore wings; the tapered body has a broad grey stripe, enclosing a central black line along the back, broad red and black and narrow white bands on each side (Plate 10).
The egg has been described as bright green in colour, and smaller than that of the Privet Hawk. A female moth captured at Brighton on July 18, 1898, deposited twenty-five eggs on Convolvulus arvensis up to July 20, and the next day a further eight were counted. The moth died on the 22nd. Caterpillars hatched out July 27-28. These were whitish green, with a rough blackish horn; after second moult they became green, with a darker green stripe along the back, but without oblique side stripes.
| Pl. 10. |
| Convolvulus Hawk-moth. |
| Pl. 11. | ||
| ||
| ||
|
In its more usual form the caterpillar, when full grown, is bright apple-green, narrowly streaked with black; oblique stripes on the sides yellowish; horn reddish, tip black. Head green, with black stripes. In some examples the side stripes are edged above with bluish black; in others there are blackish, more or less square, spots on the back, and patches on the sides. Sometimes the general colour is blackish brown, with ochreous bands and streaks. (This form is figured on Plate 9). When it occurs in these islands it is generally found on the small bindweed (Convolvulus arvensis), but it will eat C. sepium and C. soldanella, and also the cultivated kinds.
Referring to the caterpillar in Britain, Moses Harris, in 1775, wrote, "I never heard of but two that were ever found—one by Mr. South [or Smith] of Hampshire, which, he said, was green, and appeared in other respects so like the privet that he was deceived. He fed it on the leaves of the lesser bindweed. It changed into the chrysalis in the earth, in July, and the moth was produced in September" (Dale).
The caterpillar figured by Harris is of the brown form, so we see that even at this early date something was known of the life history of this moth and the variation of the caterpillar. Since that date and up to 1894 only very few larvÆ appear to have been found in our islands. Barrett states that it is doubtful if more than twenty had then been recorded. In 1895 caterpillars were obtained in Cornwall (four) and in Kent (two). Then for five years little or nothing was reported about this stage, although the moth seems to have occurred in varying numbers each year. In 1901, August and September, over one hundred were reported, rather more than half of which were taken from a hedgerow, overgrown with C. sepium, in Northumberland; twenty-six were obtained on the bindweed growing on Lancashire sandhills, thirteen or fourteen in Essex, and others in Bedfordshire, Kent, Hants, Dorset, and Devon.
Mr. Bell-Marley obtained thirty eggs, September, 1897, and although these were kept in a cold room, thirteen caterpillars hatched, September 21. They were supplied with Convolvulus arvensis and C. soldanella, and seemed to relish one as much as the other. Seven died during the first three moults. The bindweeds being nearly over, seedlings were raised by forcing, but before these were ready the larvÆ had been on short commons, and just immediately before the seedlings came to hand, had been twenty-four hours without food. On these tender seedlings and some endive the remaining larvÆ, six in number, attained full growth in December. Two subsequently died in the first half of that month, and the others went under the soil. Only one, however, managed to assume the chrysalis state.
A small caterpillar, about one week old, described by Paymaster-in-Chief G. F. Mathew ("Notes on Lepidoptera from the Mediterranean," Entom., xxxi. 115), was 1¾ inch long, pale glaucous green in colour, and thickly covered with raised white dots; oblique side stripes white, bordered above with dark green. On September 26, 1897, this caterpillar, which had been found on September 18, was nearly full grown, and the writer goes on to state that when gathering bindweed he obtained either eggs or tiny caterpillars at the same time, and he eventually found that he had eight of them altogether. They fed up rapidly, as a caterpillar, hatched about September 27, had gone down on October 18. Owing to accident, four produced deformed chrysalids, but each chrysalis resulting from the others was perfect and healthy on February 15, 1898. The large reddish-brown chrysalis is figured on Plate 11, and it will be noted that the "tongue" case forms a curious bent projection not unlike the handle of a pitcher. To give some idea of the irregular way in which this migratory species visits our islands, it will suffice to note the records only since 1894. Previous to that year it was common, more or less generally, in 1846, 1868, 1875, 1885, and 1887.
| Pl. 12. | ||
| ||
|
| Pl. 13. |
| Privet Hawk-moth. |
| Eggs, natural size and enlarged; caterpillars and chrysalis. |
In 1895 an invasion seems to have effected a landing in the autumn, on the south-west coast, chiefly, perhaps, in the Portland district, where some fifty individuals were captured between August 12 and October 7; twenty-three were caught near Bournemouth in August and September; sixteen were taken at Christchurch, August 11 to October 2; and eight were recorded from Milford. Several were reported from Devon, but only two from Cornwall, although four larvÆ were found in October at Port Wrinkle in the latter county. At Cork, in Ireland, ten specimens were obtained in October. Eastward, the captures in September were Norfolk (seven), Essex (one), Lincoln (one). Odd specimens were taken here and there in Kent, Surrey, and Herts. Several were reported from Gloucestershire, and one from South Wales. The northward extension was evidenced by the capture of one example at Alnwick, in Northumberland, in September, and of two in Aberdeenshire, one as early as August 31, the other September 9.
The moth was almost a defaulter in 1896, but in 1897 about forty specimens were taken, twenty-seven of which occurred in the Scilly Isles and eleven at Portland (August 14 to September 16). One example was reported from Yorkshire and another from Sutherlandshire, both in September.
A female was taken at Brighton, July 18, 1898, and in the autumn of that year a good many specimens were obtained in various parts of England but chiefly in the south. Portland again heading the list with over fifty (August 4 to October 3) and a number were taken in the Isle of Wight during September. Captures in 1899 seem to have been only pretty good. Portland twenty, August 25 to September 20, perhaps less than a dozen in other parts of England and one in Scotland, all in September or October. In 1900 one specimen was taken at an Eastbourne electric light, and one at Portpatrick in Scotland, both end of August. There appears to have been an arrival of moths in this country in early June, 1901. Captures were reported from Portland (June 2), Bedford, and S. W. London. LarvÆ and pupÆ were found in many parts of England, as already mentioned. Then in August, from about the 14th to September, moths were captured throughout the greater part of England; in some places caterpillars were also obtained in August, chrysalids in September. After a lull towards the end of the latter month, moths suddenly appeared again during the first week in October. Several observers remarked that whereas the August to September moths were mostly females, large in size, and not in the best condition, the later moths were chiefly of the male sex, small in size, and fine in condition. It would seem therefore that these late specimens were the descendants of the early August moths and represented a second generation on British soil and the grandchildren of the June immigrants. Or, possibly, the August-September moths were fresh immigrants, and the October specimens their offspring.
The species was observed in several English counties during August and September, 1911; and again in 1915. In 1917 it seems to have been more widely spread over our islands, as specimens were reported from Ireland and even Shetland.
Plants with tubular flowers, such as those of petunias, and the sweet-scented white tobacco (Nicotiana affinis) are its especial favourites, but it also visits the blossoms of pentstemon, geranium (chiefly the scarlet variety), etc. It does not settle on the flowers but inserts its long "tongue" into the tubes as it hovers on the wing in front of them. Just at twilight it commences operations, but it may be seen pursuing its investigations well on into the night (see Fig. 1, p. 2).
Distributed over Europe, Asia, and Africa.
The Privet Hawk (Sphinx ligustri).
A specimen of the female sex is figured on Plate 12. The white clouding or mottling on the pale brown colour of the fore wings varies in intensity and is sometimes tinged with pink, especially at the base of the wings; often it is only noticeable at the tips of the wings and on the outer area; the blackish suffusion from the inner margin through the central area and the black streaks between the veins are rather more constant. On the hind wings the pinkish tinge between the black bands may be faint or entirely absent; the central black band varies in width, and is sometimes so much expanded that it absorbs the basal half of the first band.
When full grown the caterpillar measures about three inches in length and has a very substantial appearance. It is of a pretty green colour, with seven oblique white stripes, each of which has a purplish front edging; the spiracles are yellowish. The head is rather more grass green and marked with black in front. The curved horn is blackish on the upper side and yellowish below. The colour of the caterpillar in its younger stage is yellowish, due to the presence of yellow dots, it also has some tiny hairs; the horn, which is bristly and slightly forked at the tip, is a conspicuous feature at this age on account of its length and dark colour as compared with that of the creature itself. Just before changing into the chrysalis, a brownish tinge is assumed, and very rarely caterpillars of a pinkish or purplish tint have been found.
It feeds on privet (Ligustrum vulgare) in July and August; often to be seen resting on the upper part of the longer sprays of the food plant. Sometimes a dozen or more may be found on one short strip of privet hedge. They are much subject to the attack of ichneumons. Other food plants are lilac, ash, lauristinus, and some other shrubs. Mr. Step informs me that on August 18, 1907, he found three larvÆ feeding on teasel at Ashtead.
The caterpillar will burrow some depth underground before constructing its pupal chamber. The chrysalis, which is reddish, or blackish-brown in colour, is figured with the other stages on Plate 13.