The Moths of the British Isles Volume I Part 6

It occurs throughout the greater part of England and Wales and northwards to Sutherlands.h.i.+re in Scotland. In Ireland it is abundant in many localities.

Distributed over Europe its range extends northwards to Lapland, southwards to north-west Africa, and eastward to Amurland.

PROMINENTS (_Notodontidae_).

In the majority of our moths belonging to this family there is a tooth-like tuft of scales projecting from about the middle of the inner margin of the fore wings; these, when the moth is resting, are brought together and raised above the level of the closed wings (see Fig. 11, page 11). The antennae of the male are bipectinated in most of the species, but those of _Odontosia_, _Lophopteryx_, and _Phalera_ are dentated and each tooth has a little tuft of short hair.

The moths are not often seen in the day time, but a few species are sometimes met with at rest on tree trunks, palings, etc. All fly at night and are pretty rapid on the wing; possibly if it were not for the fact that a bright light has a powerful attraction for them, the perfect insects would be rarely captured. {57} Specimens, when caught, except females which it may be well to keep for eggs, should be killed and pinned at once, as many kinds become very restless when imprisoned in a box and soon damage themselves. Females usually deposit their eggs freely, and in most cases the caterpillars are not difficult to rear when once they begin to feed.

Sometimes it is not easy to induce them to commence this very necessary business. The caterpillars, except those of _Phalera_ and _Pygaera_, are without hairs on the body; those of the true Prominents generally have one, or more, hump on the back; in some kinds the a.n.a.l prolegs or hind claspers, are small. When resting the hinder part of the caterpillar is more or less raised, several of them elevate the front portion also, and frequently the posture a.s.sumed is a most curious one.

The caterpillars of _Cerura_, _Dicranura_, and _Stauropus_ have the hind claspers transformed into tail-like appendages, which in the case of the Puss and Kittens take the form of a pair of slender tubes furnished with flagellae, or whips, which can be protruded or withdrawn as occasion may require. These organs are presumably for defensive purposes, but are not always effective in combating the attack of parasitical flies, as these evidently manage to deposit their egg on the caterpillars not infrequently.

The pupa, or chrysalis, of some kinds is enclosed in a hard coc.o.o.n on tree trunks, and others in a soft coc.o.o.n generally underground; sometimes, however, the coc.o.o.n is spun up between leaves; occasionally, as for example that of the Buff-tip, the chrysalis is found in the ground without any protecting covering, although the cell in which it was formed may have been flimsily lined with silk.

Nearly one hundred species are referred to this family in Staudinger's "Catalogue of Palaearctic Lepidoptera," and of these twenty-five occur, or have been taken, in the British Isles, nearly all of which are accepted as indigenous. Two of the {58} three species not generally regarded as true natives have been found in the caterpillar state, and the third was reared from an egg obtained with others of the same kind in Norfolk.

THE ALDER KITTEN (_Cerura bicuspis_).

This moth (Plate 22, Fig. 3) differs from either of the two next following in being whiter, and in having both margins of the central band of the fore wings angled or bent inwards above the middle; this is markedly so on the outer side. The band itself is black, inclining to purplish rather than grey. Barrett mentions a specimen without central band or cloud towards tip.

[Ill.u.s.tration: FIG. 19. COc.o.o.n OF THE ALDER KITTEN.]

According to Buckler, the caterpillar is yellow-green; head dark reddish-brown; at the back of the head commences a broad, reddish-brown blotch, which runs to a point on the back of the third segment, where is a slight elevation; on the fourth it recommences and becomes broader on each segment to the eighth, where it extends below and encloses the spiracles, thence it narrows to the tenth, continuing on the eleventh and twelfth as a broad stripe, and {59} widening on the thirteenth, where it again narrows to the tentacles; in the broad portion of this dorsal marking are faint indications of two or three orange spots; on each side it is broadly edged with pale yellow, and on the sixth, seventh, and eighth segments its margin is deeply indented. It feeds on alder and birch in July and August.

The coc.o.o.n is shown in its natural position on birch bark (Fig. 19). This was kindly lent to me for figuring by Mr. L. W. Newman, of Bexley, who also had another in which lichen as well as fragments of bark were worked into the surface, so that the coc.o.o.n was less in evidence than the one portrayed.

The moth emerges in May and June.

The first British specimen, a male, was found on alder near Preston, and was recorded by Doubleday in the _Zoologist_ for 1847. A second example was noted from the same locality in 1849. This district in Lancas.h.i.+re, and Tilgate Forest in Suss.e.x, are the chief homes in the north and the south of England respectively; but one or more specimens have occurred in Ches.h.i.+re, Herefords.h.i.+re, Oxfords.h.i.+re, Norfolk, Suffolk, and Devons.h.i.+re, and more frequently in Staffords.h.i.+re, Derbys.h.i.+re, and Yorks.h.i.+re. It does not seem to inhabit Scotland or Ireland, neither has it been recorded from Wales, so far as I can find, more than once.

The species is found in Germany, Switzerland, Eastern France, Belgium, Southern Sweden, Central Russia, Livonia, Finland, Ussuri, and a local race occurs in Amurland.

THE POPLAR KITTEN (_Cerura bifida_).

Fore wings grey, with a broad, dark grey central band, and a cloud of the same colour towards the tips of the wings; the band is inwardly margined by an almost straight black line, and outwardly by a curved line; the third line is double, and curved towards the costa, forming the inner edge of the grey cloud, the lower part is wavy. The first black line is inwardly, and {60} the second outwardly edged with ochreous, and preceding the first is a series of black dots.

The full-grown caterpillar, which is green, with a yellow-edged, purplish, irregular stripe on the back, is figured on Plate 23, together with a very young example, the purplish-black eggs as laid, and the red-brown chrysalis. The coc.o.o.n from which the chrysalis was extracted was spun up on a fairly stout twig of poplar, from which some of the bark had been torn; the coc.o.o.n was formed, as regards the upper part, on the bare twig, and this was covered with gnawed wood, instead of with bark fragments, as is the lower end. The moth is figured on Plate 22, and the early stages on Plate 23.

The moth emerges in June, sometimes in July, and may occasionally be found at rest on the trunks of poplars, on which the caterpillar feeds from July to September; also on adjacent walls or palings. The coc.o.o.ns are made up on the surface or in the c.h.i.n.ks of the bark, and may be searched for, all through the winter and early spring. It is curious to note how readily these are detected after the moth has escaped, and how difficult they are to see before that event. Usually there is but one brood in the year, but in the hot summer of 1906 a male specimen emerged from a few chrysalids that I had reared from eggs laid at the end of June of that year. On the other hand, the moth has been known to remain in the chrysalis for two winters.

The species is not uncommon in some parts of the London district, and seems to occur throughout England wherever poplars abound. It does not appear to have been found in Scotland, and is scarce in Ireland. Abroad it is found in Central Europe with a northern range to Finland, southwards to Italy and Greece, and eastwards to the Altai.

[Ill.u.s.tration]

Pl. 22.

1. POPLAR KITTEN-MOTH, _male_; 2 _female_.

3. ALDER KITTEN-MOTH, _male_.

4. SALLOW KITTEN-MOTH, _male_; 5 _female_.

[Ill.u.s.tration]

Pl. 23.

1, 1a, 1b. POPLAR KITTEN: _eggs, caterpillar and chrysalis_.

2, 2a. SALLOW KITTEN: _eggs and caterpillars_.

{61}

THE SALLOW KITTEN (_Cerura furcula_).

This moth differs from the last in its generally smaller size, but more especially in the shape of the black line forming the outer margin of the central band; this is always more or less angled or dentate towards the front margin of the wings, whereas, in the Poplar Kitten, this portion of the line forms a clean curve (Plate 22, Figs. 4, 5).

The eggs are black, rather glossy, and are generally deposited in pairs, but rarely more than three, and often only singly, on the upper surface of a leaf of sallow or willow. The caterpillar feeds from July to September, sometimes as early as the end of June, or as late as October. It is green, with a yellow tinge; the markings on the back are similar to these characters in the caterpillar of the preceding species, but, as will be seen by looking at the figures on Plate 23, they are not quite the same in outline. The figure of the young caterpillar on this plate was made soon after it left the egg, and the sh.e.l.l from which it emerged is also depicted. Sallow and willow are the usual food plants, but in August, 1906, I found a half-grown caterpillar of this species on aspen, but it died a few days afterwards. The reddish-brown chrysalis is enclosed in the usual hard coc.o.o.n of its kind, which is affixed to a branch or the trunk of the tree upon which the caterpillar fed. A depression is usually selected, and when the coc.o.o.n is finished off with its covering of bark fragments it is difficult to see.

The species is well distributed over England, Ireland, and Scotland; perhaps more frequently obtained on the mosses of Ches.h.i.+re, Lancas.h.i.+re, and Yorks.h.i.+re, than in other parts of England. It is found in Central and Northern Europe, and, according to Staudinger, in Amurland and North America. {62}

THE PUSS MOTH (_Dicranura vinula_).

Portraits of both s.e.xes of this rather common moth are given on Plate 24.

The head, thorax, and body are very fluffy. The whitish fore wings are crossed by several wave-like lines; the main veins (_nervures_) are ochreous, and the branches (_nervules_) are blackish; beyond the more or less clear basal area there is often a broad but irregular blackish band, and the wavy markings on the outer area vary in intensity (sometimes the short streaks between the veins terminate on the outer margin in black dots). Hind wings whitish in the male, and suffused with blackish in the female, to a greater or lesser extent. In some examples of the female the fore wings and the body are also tinged with blackish. The antennae are bipectinated in both s.e.xes, but those of the female have the teeth much shorter than those of the male.

The eggs are usually laid in pairs on the upper surface of a leaf of sallow, willow, or poplar. In colour these are purplish or reddish brown, s.h.i.+ning, and finely grained; a minute depression at the top is yellowish, with a black speck at the bottom of the hollow.

In its last stage the caterpillar is green, with a white or yellowish-edged purplish brown band on the back; the head is light brown margined with black and purplish behind, and the ring immediately following (first thoracic) is green margined with yellow and having two black spots on the upper part. When the creature a.s.sumes the position which Professor Poulton terms the terrifying att.i.tude, the front part is elevated, the head is drawn back into the ring next to it, and the tails are raised and curved forward over the back (see Plate 25). Seen thus from the front the appearance of the caterpillar is certainly grotesque, and no doubt affords it some protection from its enemies. It feeds on poplars, sallows, and willows, usually in July and August, but sometimes as late as September.

{63}

[Ill.u.s.tration: FIG. 20.

CATERPILLAR OF PUSS MOTH.]

The reddish brown chrysalis is enclosed in a hard coc.o.o.n spun up and securely attached to the trunk or under a limb of the tree upon which the caterpillar was nourished, or upon some other adjacent thereto. I once found a coc.o.o.n on the lower rail of a garden fence. In constructing the coc.o.o.n fragments of bark and wood are worked on the exterior, but failing these the caterpillar will make use of any available material for the purpose. If enclosed in a tumbler covered with gla.s.s it will spin a transparent coc.o.o.n. Emergence from its strong pupal chamber would appear to be a difficult matter, but the caterpillar and the chrysalis both contribute something towards a.s.sisting the final efforts of the moth to escape. The caterpillar, in constructing the coc.o.o.n, is careful to make the exit end with a thinner layer than the other parts; then the chrysalis is provided with a cutting implement in the shape of a keel-like arrangement on the fore part, and with this it operates at the right time on the weak end until a breach is made; the moth breaks the head end of the chrysalis case and moistens {64} the ruptured material with a softening fluid so that the insect is able to force its way out of the coc.o.o.n; the chrysalis case remains in the coc.o.o.n.

The moth is on the wing in May and June, and sometimes July. Three specimens that I reared this year (1907) from eggs found on a leaf of poplar last year, emerged on June 4th, 10th, and July 12th. They all pupated about the same time, and side by side on cork bark.

I believe this species has not been recorded from the Orkneys or the Shetlands, but with these exceptions it seems to occur in more or less frequency throughout the United Kingdom. It is widely distributed in Europe, and its range extends to Siberia. In Lapland, Amurland, j.a.pan, and North Africa it is represented by named forms.

THE LOBSTER (_Stauropus f.a.gi_).

The English name of this insect does not apply to the greyish brown or sometimes blackish moth (Plate 26), but to its remarkable caterpillar, the figures of which, on Plate 27, are reproduced from drawings by Mr. Alfred Sich. In colour this curious-shaped creature is always some shade of brown, the head is marked in front with reddish, the ring divisions of the body are darker brown, and the hind rings are reddish brown.

The late Mr. W. H. Tugwell, referring to the early history of these caterpillars, states that a female of the blackish form received from Reading in May was kept alive for seven days, during which time she laid a few eggs on oak leaves each night; "all told" she produced forty eggs. As she was then quite exhausted, a good many had probably been laid previously. The eggs when first laid are of a pale cream colour, hemispherical in shape and flattened beneath. About the seventh day a circular depression, and a dark spot, appear, and gradually the entire egg a.s.sumes a dull purplish colour. "On the tenth day the caterpillars hatch out. When they first leave the sh.e.l.l they appear extremely large, this is partly on account of the long legs and the caudal appendages which are ever nervously twisting about. The young caterpillars most carefully keep guard over their own egg-sh.e.l.l, which is to them an all-important item, as this provides them with their first meal--the first and only food they take for seven days, in fact, for a longer period, as it is not until after moulting their first skin that they eat any other food. This fact I proved over and over again, as, being an invalid, my time was quite free to watch them hour after hour and day after day. As soon as they have eaten their way out of the sh.e.l.l they stretch themselves, and then from time to time nibble portions of the white chitinous-looking egg-sh.e.l.l, and a tough morsel it seems to be for them; but they never leave it for more than an inch or so, and then rapidly come back. They keep nervously moving around and about this, and if perchance another caterpillar should approach within touch of it, a vigorous attack is made to drive off the intruder. All going well during the first hour or two, the whole of the sh.e.l.l, or sometimes not more than from half to two-thirds of it is consumed; and once the caterpillars really leave the egg-sh.e.l.l, that is, walk away from it, they do not touch it after. If by any chance a young caterpillar gets driven away from the egg-sh.e.l.l, death is certain to result, as I could never induce them to feed on portions of empty sh.e.l.ls left by others; nor would they eat the leaves or the brown stipules of the beech, which it has been suggested they do eat. In no single instance did they eat other food in their first skin save and alone the one meal of their own egg-sh.e.l.ls."

[Ill.u.s.tration]

Pl. 24.

PUSS MOTH.

[Ill.u.s.tration]

Pl. 25.