The Moths of the British Isles Volume I Part 12

Pl. 45.

1. REED TUSSOCK MOTH, _male_; 2 _female_.

3, 4. BROWN-TAIL _varieties_.

{103}

The caterpillar, which is hairy and variegated with reddish and black and white, may be recognised by the large bright white marks on the back. It is often seen in the daytime on the boles or branches of poplars, as well as on the foliage. It frequently falls a victim to the parasitical flies, and it is probably due to these enemies that the species is less common in some years than in others. Besides poplar, it will feed upon sallow and willow.

Hibernating when quite tiny, it reappears in April, and, feeding up, is ready to enter the chrysalis state in June or July, when it spins a flimsy silken coc.o.o.n among the leaves, or in some suitable cranny on the tree or bush. The moth is shown on Plate 43, Fig. 6, and the caterpillar and chrysalis on Plate 44, Fig. 2, 2a.

The moth emerges in July or August, and may be found resting on or under the leaves, and on stems and branches of the trees upon which the caterpillar fed, or on palings, etc., adjacent thereto.

Distribution, Northern and Central Europe, Iberia, Corsica, Italy, Balkan Peninsula, South-east Russia, North-east Asia Minor, and Armenia. In the Far East, including China, Corea, and j.a.pan, it is represented by the var.

_candida_, Staud.

THE GIPSY (_Lymantria dispar_).

Up to some sixty-five years ago, this species (Plate 46, Figs. 1 [male], 2 [female]) seems to have flourished in a wild state in the fens of Norfolk and Cambridgeshire, and also in Huntingdonshire. Just how long it had been common in those localities history does not inform us, but about 1792 Donovan was unable to obtain a native specimen to figure. Stephens, however, writing in 1828 states that at that time it abounded in the Huntingdonshire fens. "It is said," he remarks "to have been introduced into Britain by eggs imported by Mr. Collinson, but the abundance with which it occurs near {104} Whittlesea, and the dissimilarity of the indigenous specimens (which are invariably paler, with stronger markings) to the foreigner, sufficiently refute that opinion." There appears to be no doubt that some time near 1840 the Gipsy moth began to decrease in numbers, and that about 1850 it had almost or quite ceased to exist, as a wildling, in England. At the present time, and probably since the date last mentioned, the species has been semi-domesticated, and so reared year by year, at first possibly direct from the original wild stock, but afterwards from fresh stock derived from eggs of foreign origin. Futile attempts have been made to re-establish the species in various parts of England, and also in Ireland. Such failure is curious, seeing that in America the accidental introduction of a few moths has resulted in the species becoming so numerous that at least one state has been expending thousands of dollars in endeavouring to destroy it. The eggs are laid in batches and covered with the down-like scales from the a.n.a.l tuft of the female.

The caterpillar hatches in April, and in warm weather feeds up pretty quickly. It is grey, covered with black dots and fine marks; the hairs arising in spreading tufts from the raised warts, are longer on the sides than on the back; these warts on the back on each side of the pale central line are bluish on rings one to five, and reddish thence to eleven. Head, pale brown marked with black. Feeds on the foliage of most fruit trees, also on oak, elm, sallow, hawthorn, and sloe.

Chrysalis rather hairy, brownish in colour, in a fairly strong silken coc.o.o.n, which is spun up in any suitable angle.

The moths appear in August, and there is a striking difference in the size and coloration of the s.e.xes. The male is pale or greyish brown, lined and clouded with darker brown on the fore wings, and the female is whitish with brownish cross lines, and a black central V-mark on the fore wings.

Distributed over the whole of the Palaearctic Region, except {105} the most northern, and, as adverted to, it has now become a pest in parts of North America.

THE BLACK ARCHES (_Lymantria monacha_).

Two examples of each s.e.x of this moth are figured on Plate 46, and these show the normal form of the species; the central markings of the fore wings vary in width and intensity, and in some specimens the whole of the central area is more or less filled up with black or sooty black. Sometimes the wings are partially suffused with blackish, and the normal markings are consequently somewhat obscured. Examples wholly suffused with black are referable to var. _eremita_, a form not uncommon on the continent, and modifications of it are found in a wild state in this country. By selecting parents showing a tendency to vary in the direction of this dark form, it has been found possible to obtain a good percentage of darkened specimens, some of them closely approximating to var. _eremita_.

The early stages are figured on Plate 47.

The eggs of this species are laid in August in the c.h.i.n.ks of bark on tree trunks, and do not hatch until the spring.

Caterpillar, whitish varying to greyish, a deep brown stripe along the middle of the back with an irregular black line on each side of it; the stripe is interrupted by a whitish or greyish patch on rings seven to nine; on ring two there is a black mark, and occasionally red dots appear on eight and nine; black dots on the back and sides are furnished with hairs.

Head, brownish marked with a paler tint. It feeds from April to July on the leaves of oak and various other trees, including apple and pine.

The chrysalis, which is enclosed in a somewhat transparent silken coc.o.o.n spun up in a fissure of the bark, is brownish, hairy, and has a very glossy metallic appearance.

The moth emerges at the end of July and in August. It flies {106} at night, and may be seen resting by day on the trunks of trees. Although it occurs in most of the counties of England from Yorkshire southwards, and in some parts of Wales, it is nowhere so often met with as in the New Forest, Hants.

Distribution, Central Europe extending to parts of Northern Europe, and southwards to North Italy and Greece, and eastwards to Ussuri and j.a.pan.

LACKEYS AND EGGARS (_Lasiocampidae_).

Staudinger in his catalogue of Palaearctic Lepidoptera refers twenty genera comprising sixty-three species to this family. Of these, eleven species belonging to ten genera occur in the British Isles. According to some authorities a twelfth species, _Dendrolimus pini_, Linn., should be included. This is the _Eutricha pini_ of Stephens (1828) and the "Wild Pine tree Lappet moth" and "Pine tree Lappet" of the more ancient authors. The claim of this species to a place in the British list rests chiefly on a specimen captured in the Norwich Hospital, in July, 1809, by Mr. Sparshall.

Wilkes (1773) states that he once found a caterpillar near Richmond Park, but the moth was not reared. For generations the species now cla.s.sified as Lasiocampidae have been referred to Bombycidae, but the silkworm (_Bombyx mori_) is typical of that family, which has but few genera in it, and none of them occur in Europe. Although some of the moths are of considerable size, most of them are not large. The general colour is some shade of brown. Both s.e.xes have the antennae bipectinated, but more strongly in the male than the female.

In his treatment of the species here included under Lasiocampidae, Tutt. ("A Natural History of the British Lepidoptera," vols. i., ii.) separates them into two families, Lachneidae and Eutrichidae. The first family is divided into five sub-families and the same number of tribes. The latter family has three sub-families and three tribes. The whole are embraced in a super-family styled Lachneides. Lasiocampidae disappears as a family name, but the genus _Lasiocampa_ is retained for _quercus_, L., whilst _trifolii_, Schiff., is referred to the genus _Pachygastria_, Hb., and these with _Aurivillia_, Tutt, not represented in Britain, const.i.tute the Pachygastriidi tribe of the Pachygastriinae, a sub-family of Lachneidae. All this will no doubt appear very complicated to the beginner, but he need not worry himself very greatly about the matter at present. When he feels that he has a fair knowledge of the species in the group he will be in a position to grapple with the niceties of cla.s.sification.

[Ill.u.s.tration]

Pl. 46.

1. GIPSY MOTH, _male_; 2 _female_.

3, 4. BLACK ARCHES, _males_; 5, 6 _females_.

[Ill.u.s.tration]

Pl. 47.

BLACK ARCHES MOTH.

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

{107} THE LACKEY (_Malacosoma neustria_).

The colour of the male ranges from pale yellow ochre, through pale brown to reddish or dark brown; and in the female from pale brown to reddish brown; two cross lines are generally present on the fore wings; the s.p.a.ce between the lines is usually darker in the female, and sometimes in the male also, forming a dark central band. All these colour forms were reared from some caterpillars taken by myself at Byfleet, Surrey, in 1901. Another year a few caterpillars taken at Esher produced ochreous coloured males and pale brown females only; the bands of the latter were narrower than usual and much contracted below the middle. As the females last mentioned are somewhat under the normal size I am inclined to think that the caterpillars from which they were reared had been on short commons during their last stage. Two males and a female are shown on Plate 48.

The greyish brown eggs are laid during July and August in a ring cl.u.s.ter around a twig as shown on Plate 49, and so they remain exposed to all weathers during the winter. In April the caterpillars hatch out, and as they live in company throughout the greater part of their larval existence, the first business is to {108} construct a silken tent-like web (Fig. 22).

The exterior of the tent affords a suitable surface upon which they can lie when they take a sun bath, which they seem fond of doing whenever the opportunity offers. It is also used, as well as the interior, for the process of skin-changing.

[Ill.u.s.tration: FIG. 22. WEB OF LACKEY CATERPILLARS. (Photo by W. J.

Lucas.)]

The full-grown caterpillar is slaty blue above; along the middle of the back is a bluish white line, bordered on each side by a reddish-orange-lined black stripe; towards the lower limit of the slaty blue colour is a black edged reddish-orange line, and below this again the ground colour is flecked with orange, sometimes forming a line in the region of the spiracles; there are two velvety black spots on the back of the ring nearest the head, and a smaller black spot on each side of the next two rings; the hairs are brownish, rather more numerous on the sides than on the back. Head slaty-blue with two black eye-like spots. It feeds from April to June on hawthorn, sloe, and various fruit trees in orchards and gardens; also on birch, elm, oak, sallow, willow, etc.

Chrysalis blackish, rather downy enclosed in a double {109} oval-shaped coc.o.o.n; the inner compartment is of rather closer woven silk, and is thickly covered with a yellowish substance, which is ejected by the caterpillar as a fluid, and afterwards drying forms a sulphur-like powder on the coc.o.o.n, and in a lesser degree on the chrysalis also. The moth is on the wing in July and August, but it is rarely seen in the daytime, and not often at night, except when attracted by light into the house, or to the gas or electric lamps. It is exceedingly easy to rear, either from eggs or from collected caterpillars; the latter are often abundant.

Generally distributed throughout England, but becoming scarcer from the Midlands to Lancashire and Yorkshire, and not often occurring further north than the last named county. In Ireland it is unknown in the north, but occurs in many parts of the south and south-west.

THE GROUND LACKEY (_Malacosoma castrensis_).

This also is a variable species. Most frequently the fore wings of the male are pale buff, cross lined, and more or less clouded with brown; hind wings brown. The female has all the wings reddish brown, the front pair being crossed by two pale buff lines. The fringes are pale buff, chequered with brown in both s.e.xes. Colour and marking are, however, subject to considerable variation. Sometimes all the wings are pale buff (male), or reddish brown (both s.e.xes), and the fore wings without marking. The cross lines on fore wings of the female may be either very slender or very broad; occasionally almost the whole of the basal area up to, and including, the first cross line is buff. Two examples of each s.e.x are shown on Plate 48.

The eggs are laid in a similar manner to those of the last species, around stems of wild carrot, sea wormwood, and other {110} plants that flourish in the insects' favourite haunts, which, in this country, are the salt marshes along the estuaries of the Thames and Medway.

The caterpillar is black, inclining to bluish between the rings; along the back are four much broken reddish orange lines and a central bluish line; a bluish stripe followed by a reddish one along the sides, and below this the colour is bluish, speckled with black; the hairs are golden brown. Head blackish grey, without black spots (Plate 49, Fig. 3).

The chrysalis and its coc.o.o.n are similar to those of the Lackey, and spun up among herbage.

The moth emerges in July and August and, although it may be occasionally attracted by light, is rarely seen in the open. The caterpillars are to be found, most years, in plenty from May to July. They feed on almost every kind of plant growing on the salterns, and as they are fond of sunning themselves on sea wormwood, sea plantain, etc., are easily seen at such times. In dull weather they retire to their webs, which are generally rather low down in the herbage. In confinement they will do very well if supplied with fresh sprays or leaves of almost any fruit tree, or of birch, whitethorn, etc. The receptacle containing them should be constructed and placed so that the caterpillars get plenty of air and sunshine. It is considered desirable to sprinkle both food and caterpillars with water now and then; some rearers deem it necessary to put a tiny pinch of salt in the water used for sprinkling; and in my own experience I have found that better results were obtained when the food was thus treated than when the salt was omitted.

On the continent this species occurs in woods, and on heaths, etc., but in Britain it is seemingly confined to salt marshes. Although it has been recorded from the Suffolk coast, and other places, the best localities for it are probably the salterns, from Gravesend to the Isle of Sheppey, and at Southend and s...o...b..ryness.

[Ill.u.s.tration]

Pl. 48.

1, 2, 3. LACKEY MOTH.

4, 5, 6, 7. GROUND LACKEY.

[Ill.u.s.tration]