The Moths of the British Isles Volume I Part 3

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.

[Ill.u.s.tration]

Pl. 10.

CONVOLVULUS HAWK-MOTH.

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Pl. 11.

1. CHRYSALIS OF DEATH'S-HEAD HAWK-MOTH.

2. " " CONVOLVULUS " "

3, 3a. CATERPILLAR AND CHRYSALIS OF PINE HAWK.

{29} 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 Hamps.h.i.+re, 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 larvae 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 {30} Northumberland; twenty-six were obtained on the bindweed growing on Lancas.h.i.+re sandhills, thirteen or fourteen in Ess.e.x, and others in Bedfords.h.i.+re, 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 larvae 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 larvae, 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 a.s.sume 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._, x.x.xi.

115), was 1 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.

[Ill.u.s.tration]

Pl. 12.

1. PRIVET HAWK-MOTH.

2. PINE HAWK-MOTH.

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Pl. 13.

PRIVET HAWK-MOTH.

_Eggs, natural size and enlarged; caterpillars and chrysalis._

{31} 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 larvae 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), Ess.e.x (one), Lincoln (one). Odd specimens were taken here and there in Kent, Surrey, and Herts. Several were reported from Gloucesters.h.i.+re, 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 Aberdeens.h.i.+re, 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 Yorks.h.i.+re and another from Sutherlands.h.i.+re, 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 {32} 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. Larvae and pupae 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 s.e.x, 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. {33}

THE PRIVET HAWK (_Sphinx ligustri_).

A specimen of the female s.e.x 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 gra.s.s 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 a.s.sumed, 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 {34} August 18, 1907, he found three larvae 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.

The moth usually emerges the following June or July, but there are at least two records of its remaining in the chrysalis during two winters.

The southern portion of England appears to be the princ.i.p.al British home of this moth. It is more or less scarce in the midlands and northwards. In Scotland it has only been recorded from southern counties, and in his "Catalogue of the Lepidoptera of Ireland," Kane states that he has no certain record of its occurrence in that country. Widely distributed through central and southern Europe, extending northwards to south Sweden and Finland, and eastwards to Amurland, China, and j.a.pan.

THE PINE HAWK (_Hyloicus pinastri_).

Stephens, writing of this species in 1828, remarked that about thirty years before that date, a specimen "was taken in June at Colney Hatch Wood, and a second in the neighbourhood of Esher." He also gives Rivelston Wood, near Edinburgh, as a locality, on the authority of Dr. Leach. A specimen was stated to have been seen in c.u.mberland in 1827 or 1828, and up to the year 1877 four other examples were reported, each from a different part of England. In the year last mentioned a specimen was recorded from Woodbridge, Suffolk, as taken in a rectory garden the previous midsummer (since ascertained that the moth was first seen there in 1875); an example was also found at rest on a tree trunk at Tuddenham, near Ipswich, in July, 1877, and one was reared on August 5, 1876, from a {35} chrysalis found near Horham Rectory, Wickham Market, Suffolk. In 1878-9, caterpillars were met with at Leiston, Suffolk; the moth was found in the pine woods around Aldeburgh, 1881, and as many as forty specimens were taken in July and August, 1882, and rather more than twenty in August, 1919. In 1895, Lord Rendlesham, when driving through the fir woods in the neighbourhood of Woodbridge, noted two specimens in almost the same spot where he had taken some moths in 1892-93. Mr. F. Mellusson, writing from this district (August 2, 1895), stated that fifteen specimens had been taken, and that others could have been captured; also that about one hundred larvae were then feeding in confinement. He also mentioned that 1895 was the fourth year out of five that the insect had occurred there. A male moth was found at rest on an oak trunk near Southwold, Suffolk, on July 29, 1900. On August 13, 1906, the Rev. A. P. Waller saw a worn specimen on a pine trunk in the rectory garden at Woodbridge. He also noted a pupa on September 30, 1917.

(Plate 12, Fig. 2.)

The mature caterpillar, which feeds on pine needles, is green, with a yellowish-edged reddish line along the middle of the back and a creamy line on each side of this; the interrupted line below the reddish spiracles is yellowish or ochreous. Head yellowish brown; horn blackish brown; both are glossy. It enters the earth and there turns to a reddish brown chrysalis; this is rather glossy, somewhat darker above than below, and appearing blackish between the rings; the rough "tongue" sheath is short and attached throughout to the case; the tail spike is roughened, and has a blunt point on each side of it (Plate 11, Figs. 3, 3a).

It has been recorded that caterpillars hatched from the egg early in August, pupated in October, and the moths emerged the following May-July.

The perfect insect sits upon tree trunks, chiefly pine, often well within reach, although sometimes its position is fourteen or {36} fifteen feet up the trunk. At night it visits flowers, and seems to be most partial to those of the honeysuckle.

Suffolk seems to be the British home of this species, but odd specimens have been reported since 1860 from Romsey, Hamps.h.i.+re; Hinton St. George, Somersets.h.i.+re; Herefords.h.i.+re; Isle of Mull (two caterpillars); and Bournemouth.

The range of this species is through Northern and Central Europe southwards to Northern Spain and Italy, and eastward to the Caucasus. In j.a.pan it is represented by var. _caligineus_, Butler, which differs but little from typical _pinastri_.

THE SPURGE HAWK (_Deilephila_ (_Hyles_) _euphorbiae_).

The fore wings are pale grey, more or less tinged with pinkish and marked with olive at the base, towards the middle of front margin, and a tapered band running from the inner margin to the tip of the wing; the lower part of the basal patch is blackish. Hind wings pinkish with black basal patch and a band before the outer margin; a white patch at a.n.a.l angle (Plate 15, Fig. 1).

The caterpillar feeds, August and September, on spurge (_Euphorbia paralias_, and _E. cyparissias_). When full grown the head is crimson red, marked on the crown with black; the body is black, but so thickly sprinkled with yellow dots that much of the black colour is obscured; the larger spots are often crimson, but sometimes they are yellow, or even cream coloured; the stripes along the back and below the yellow spiracles are crimson, as also are the legs and feet; the spiny horn is crimson with a black tip. In a younger stage the head and the horn are orange, the latter black tipped; the body is yellow with patches of black around the paler yellow spots on the back. Chrysalis pale brownish, minutely dotted with black; the head and thorax are marked with blackish, and the rings of the body have narrow, interrupted, blackish bands; the wing and antennae cases are covered with fine short blackish streaks; tail spike blackish, somewhat flattened, and the acute point black (Plate 1, Fig. 1; 14, Figs. 2, 2a).

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Pl. 14.

1, 1a. BEDSTRAW HAWK-MOTH.