The Moths of the British Isles Volume I Part 18

In size, colour of the fore wings, and general appearance this moth might be mistaken for the much more common Green Tortrix (_Tortrix viridana_). On examination however, it will be seen to have white hind wings, whilst those of the _Tortrix_ are grey. Again, the head, front of thorax, and front edge of the fore wings are white in the present species (Plate 73).

The caterpillar is green, inclining to whitish on the back, the latter lined with brownish, and bearing warts on rings six and eleven. It feeds in July and August on the terminal leaves of osier and willow; these leaves are drawn together with silk, and the solid appearance of the foliage at the end of the twig will afford a clue to the probable whereabouts of the caterpillar when one is searching for it. Chrysalis, brown, darker on the back, paler on the under parts, and on the wing covers; enclosed in a tough boat-shaped coc.o.o.n which is often constructed on the bark of a twig or stem of the food plant. As a rule the moth does not emerge until the following year, but in some years a few will appear in the autumn, and others remain in the chrysalis until the following May or June.

This species inhabits damp places where there are osiers, {145} and it is especially common in the fens. It occurs in most of the southern and eastern counties of England, but does not seem to be recorded from other parts of the British Isles.

GREEN SILVER LINES (_Hylophila prasinana_).

The bright green fore wings are crossed by two shaded silvery lines, and a narrow silvery band, the latter running from the tip of the wing to the inner margin, and usually there is a whitish shade between the two lines; the fringes are reddish, or pinkish, and the front and inner margins are tinged with the same colour, sometimes strongly so on the inner margin. The hind wings of the male are whitish, tinged with yellowish green; fringes white, more or less tinted with reddish; in the female the hind wings are entirely silky white. Antennae reddish (Plate 73).

Caterpillar, green, with yellowish dots, lines on the back, and edging to first ring of the body; the a.n.a.l claspers are marked above with red. It feeds in August and September on the leaves of oak, birch, beech and nut (Plate 72).

The chrysalis is purplish above merging into pale brown beneath; wing-cases ochreous brown; the dorsal surface, especially the ring divisions, are dusted with whitish dots. It is enclosed in a papery coc.o.o.n of a pale pinky brown colour; frequently spun up on the back of a leaf, but also in a curled leaf, bark c.h.i.n.k, or among herbage and litter on the ground.

The moth flies in June and July, and is not uncommon in woods throughout the greater part of England, it may be beaten from trees, and is often to be seen sitting on bracken and other undergrowth. It is also found in Scotland up to Moray, and seems to be pretty generally distributed in Ireland. The range of this species abroad extends through Northern and Central Europe, South Russia, Siberia, to j.a.pan. {146}

SCARCE SILVER LINES (_Hylophila bicolorana_).

The green colour of the fore wings of this moth is rather paler than of those of the last species; they are crossed by two almost parallel yellowish lines; hind wings white and silky. Antennae whitish towards the tip and reddish towards the base (Plate 73).

Caterpillar green, sometimes tinged with yellow, a dark line along the middle of the back is edged on each side with whitish.

The chrysalis is pale greenish, with a narrow black stripe from the head along the thorax extending to the fourth abdominal ring; the wing cases reach the sixth ring, which together with the back of the fifth are roughened with fine blackish points.

Coc.o.o.n boat-shaped with the keel raised at the head end. When the moth emerges from this end the coc.o.o.n closes up tightly again, so that no opening is to be seen; slight pressure on the back will cause the exit slit to open.

This rather local species is perhaps commoner in the eastern counties of England than elsewhere, but it occurs in the oak woods of Berkshire, and southward to Kent and Hampshire. Much scarcer in the west and midlands, and apparently unknown in the north. Barrett gives Galway and Queen's County in Ireland, but adds that it is rare.

Distributed over Central and Southern Europe, and its range extends to South Sweden, and Asia Minor.

SARROTHRIPINae.

THE LARGE MARBLED TORTRIX (_Sarrothripa revayana_).

This is a most variable species, ranging from greyish white through various shades of brown to blackish; the grey and the {147} brown forms are sometimes tinged with green. In the ill.u.s.tration some of the more usual forms of marking are shown. 1 (more or less typical) and 2 are the most common; 5 (_ramosana_) is less frequently met with; 4 (_ilica.n.u.s_) has ashy brown fore wings with a black bar at the base, three black dots on the disc, and a series of black dots before the outer margin, the triangular marking on the front margin is reddish; 3 is a modification of the typical form approaching var. _dilutana_; 6 is of the _afzelia.n.u.s_ form, with shiny brownish fore wings and black markings.

[Ill.u.s.tration: FIG. 23.

LARGE MARBLED TORTRIX.]

The caterpillar is green with whiter ring divisions; a few long whitish hairs on each segment; a faintly darker line along the back, and a paler interrupted line along the sides. Head yellowish green marked with brownish and spa.r.s.ely clothed with whitish hairs. It feeds in June and July on the leaves of oak and sometimes on sallow. It spins a whitish boat-shaped coc.o.o.n on the under side of an oak leaf or twig, and therein turns to a pale green chrysalis with a broad purple brown stripe along the back from the head; the blunt last ring is tinged with purplish brown and the edge of the ring immediately before it is fringed with minute hooks (Plate 72, Figs. 4, 4a).

The moth seems to be out from August to April. It may be {148} beaten from trees and bushes throughout the autumn, and during the later months of the year it seems to hide in yews and hollies. Just before dusk it becomes active and may then be netted as it flies; later on it may be seen regaling itself on overripe blackberries, or on the ivy blossom, and it is not an infrequent visitor to the sugar patch.

The species has been found in almost every part of England and Wales wherever there are oak woods. In Scotland it occurs up to Argyllshire and Moray. For Ireland, Kane gives Tyrone, Westmeath, Galway, Kerry, and Limerick.

Distribution abroad: Central and Southern Europe, extending northwards to Scandinavia, and eastwards to Amurland and j.a.pan.

ARCTIIDae.

In this family Staudinger includes 161 species known to occur in the Palaearctic Region. About forty of these are found in Europe, and thirty-one of the latter rank as British species.

The family is usually divided into two sub-families--Arctiinae and Lithosiinae, fifteen of our species being referred to the former and sixteen to the latter. In both groups the caterpillars are hairy, but the hairs are usually longer in those of the "Tigers" than in those of the "Footmen"; the latter, too, are lichen feeders, whilst the others prefer the foliage of plants.

TIGER MOTHS (_Arctiinae_).

The moths in this sub-family have short, or, rather, stout bodies, and ample wings; and as the tongue is imperfectly developed in most of the species, flowers have not the same attraction for them as for the long-winged and slender-bodied Lithosiinae, most members of which have this organ well developed.

[Ill.u.s.tration]

Pl. 74.

WHITE ERMINE MOTH.

_Caterpillar, chrysalis and coc.o.o.n._

[Ill.u.s.tration]

Pl. 75.

1, 2, 3. WHITE ERMINE MOTH.

4, 5. MUSLIN MOTH, _females_; 6 _male_.

7. WATER ERMINE, _male_; 8 _female_.

{149}

THE WHITE ERMINE (_Spilosoma menthastri_).

Older English names for this generally distributed and often common species are The Great Ermine Moth of Wilkes (1773), Harris (1778), and The Large Ermine of Haworth.

On Plate 75 will be found three colour-forms of the moth. Fig. 1 has the typical whitish colour, Fig. 2 is creamy on the fore wings, and Fig. 3 has the fore wings buff. The last represents a specimen from Scotland, where, especially in the western parts of the country, and also in the north of Ireland, and the north-west of England, buff forms, both paler and much darker than the one figured, are not uncommon. Sometimes the Scottish specimens have smoky hind wings. As regards the black spots on the wings, the species is subject to considerable variation. In some examples almost all the markings are entirely absent; in others they are very small and numerous, or large in size and number; the central spots on the fore wings are often united, forming irregular designs. Again, there may be an unusual amount of black spotting on the outer margins, and all other parts of the wings free of spots. All these aberrations in marking, except, perhaps, the central cl.u.s.ter, seem to occur in the various colour forms. An uncommon form, known as var. _walkeri_, Curtis (Plate 78, Fig. 5), has the black scales gathered together into streaks along the nervures of the fore wings; modifications of this variety have also been found, or reared. Possibly by the careful selection of parent moths showing tendency to the streaked aberration it might happen in a generation or two that var. _walkeri_ would turn up in the breeding cage to reward the rearer for trouble taken in the experiment.

The caterpillar, which is often not uncommon in gardens in August and September, or even later, is brown, with long hairs, and a reddish stripe along the middle of the back. It feeds on {150} the foliage of low-growing plants, and does not appear to be specially attached to any particular kind. The chrysalis is dark brown, in a close-fitting coc.o.o.n of silk and hair from the caterpillar, spun up in odd corners on the ground or at the base of a wall or fence, sometimes between the pales (Plate 74).

The moth emerges in June, and may be seen sitting on walls, fences, trees, or on the herbage growing on hedge banks; or even on the bare ground. It often flies into houses when lighted up, and is a frequent attendant at the public gas lamps and electric lights. The geographical range of this species extends through Northern and Central Europe southward to North-West Africa, and eastward to Amurland.

THE WATER ERMINE (_Spilosoma urticae_).

The specimens of this white moth, depicted on Plate 75, are of the form usually met with in Britain. To Haworth, Stephens, and other early entomologists this was known by the English name of the "Water Ermine" (_S.

papyrata_, Marsham), whilst a rarer form--with a minute dot on the disc of the fore wings, and three dusky spots on the hind wings, as in the White Ermine--was the "Dingy White" of Haworth. Occasionally specimens are obtained with extra black spots on the basal and front areas of the fore wings.

Caterpillar, dark brown with a purplish tinge, the hairs, arising in spreading tufts from black warts, are dark brownish; spiracles white; head black and glossy. Feeds in July and August on a variety of marsh plants, among which are yellow loosestrife (_Lysimachia vulgaris_), mint (_Mentha aquatica_), lousewort (_Pedicularis_), water dock (_Rumex hydrolapathum_), and iris. It seems to affect plants growing under bushes, rather than those more exposed. It is, presumably, not difficult to rear in confinement, as there is a record of eight broods belonging to three generations, and all descendants of a captured female, having been reared by Mr. Bacot.

Chrysalis dark reddish brown, in a coc.o.o.n similar to that of the last species.

[Ill.u.s.tration]

Pl. 76.

BUFF ERMINE MOTH.

_Eggs, natural size and enlarged; caterpillar, chrysalis and coc.o.o.n._

[Ill.u.s.tration]

Pl. 77.