The Moths of the British Isles/Chapter 4
THYATIRIDÆ.
The nine British species next to be considered belong to the old family Cymatophoridæ, but as the name Cymatophora, as indicated by Hübner in the "Tentamen" (1816), is now generically used by authors for some species of Geometridæ; and as Hübner's Verzeichniss generic names will have to be used for the species previously included in Cymatophora, Tr., the term Thyatiridæ has here been adopted for this family—the Polyplocidæ of Meyrick and others.
The Buff Arches (Habrosyne derasa).
This pretty species (Plate 36, Figs. 1, 2) is well distributed over the greater part of England and not at all uncommon in the more sylvan districts of the southern counties. It occurs in Wales but has only once been recorded from Scotland. In Ireland it is found in almost every well-wooded locality, but is not generally common. The moth hides among the foliage of the bramble and also creeps under the withered leaves on the ground. It comes freely to sugar, and is often the earliest to attend the banquet, but is rather skittish at first and should be given time to settle down.
The fore wings are pale olive grey with two whitish streaks across them, the first oblique approaching the second towards the inner margin; the space between the streaks is clouded with brownish buff and there is a whitish cloud on the costal area, and some strongly waved cross lines before the second streak.
The caterpillar, which is rusty brown, with a blackish central line on the back, a black edged yellowish spot on ring four, a smaller one on ring five, and sometimes a tiny one on ring seven, feeds in August and September, sometimes later, on bramble, and is said to eat hawthorn and hazel. It hides during the day and comes up to feed at night. The chrysalis, which is enclosed in an earthen cocoon below the surface of the ground, or sometimes among moss, is purplish black with the ring divisions reddish; the anal spike is furnished with hooks. As a rule the moth does not emerge until June or July following the year of pupation, but it has been found on the wing in September and October.
Distributed over Central Europe, extending into Southern France, and Northern Italy, Southern Sweden and Livonia, and eastward to the Himalayas, Corea, and Japan.
The Peach-Blossom (Thyatira batis).
The olive brown fore wings of this moth are adorned with five pink-tinged whitish spots, and clouded with brown; the pink tinge varies in amount and in brightness, and sometimes gives place to pale ochreous. The moth is figured on Plate 36, and the early stages on Plate 37.
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| Pl. 36. | ||||
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| Pl. 37. | ||
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The fluted greenish-white eggs are laid upon the edges of bramble-leaves.
The caterpillar is pale reddish brown shaded with darker and freckled with whitish (in the young stage the second and third rings are whitish above); a slender dark brown line along the middle of the back, and a broader one along the sides, the latter not distinct on the first three rings; the two rings nearest the head each have a divided ridge, the second being the larger; there are also similar ridges on the fifth to ninth rings, and the back of ring eleven is slightly raised; a series of pale triangular marks on the back. It feeds on bramble in July, and may be found from that month until September.
In confinement it will thrive on raspberry or the cultivated kinds of blackberry. From some thirty eggs I had in June this year (1907) the caterpillars hatched on the 27th; several of these fed up rapidly and one or two had spun up for pupation, among the leaves, in July (about 24th), whilst others remained quite small, and a few were in the last skin but one. Early in August the larger caterpillars just referred to pupated, and the smaller ones began to feed up, and by the end of the month they had attained to full growth, although they did not spin cocoons until the second week in September.
From July chrysalids moths will often emerge in August or September of the same year, but none have appeared from those under observation. The chrysalis is pale brown mottled with dark purplish or reddish brown, wing cases reddish. The species frequents woods or wooded localities, and is generally distributed throughout England and Wales, but commoner in some parts than others. Rather local in Scotland but not uncommon in Perthshire. Sometimes very abundant in Ireland, occurring in similar localities to the preceding species. It is found over the greater part of Northern and Central Europe, and as far east as Amurland and Japan.
The Figure of Eighty (Palimpsestis octogessima).
This moth (Plate 36, Figs. 5, 6) may be distinguished by two whitish marks on the fore wings which have some resemblance to the numerals 80, hence the common name. These are really the white outlines of the reniform and orbicular stigmata, each of which has the central part filled in with black; sometimes the lower portion of the 8 is obscure, but in a general way the character is not difficult to make out.
The caterpillar is yellowish tinged with greyish on the back; a greyish plate on the back of the ring nearest the black marked orange head; three black spots on each side of the first ring, two such spots on ring two, and one on each side of rings three to eleven; the back of the last ring has a greyish plate. It feeds in July and August, earlier or later in accordance with season, on poplar. During the day it hides between united leaves, or in a curled up withered leaf, upon the tree. The shining black chrysalis with somewhat reddish ring divisions is enclosed in a rather loosely constructed cocoon spun up between leaves, or among moss etc., at the base of poplar trees. The moth emerges in May or June. It is partial to sugar, and is said to prefer its sweets served up on poplar trunks. Probably it is most often and regularly obtained in the Eastern Counties, but it is locally not uncommon in Worcestershire and Herefordshire; also found in Gloucestershire, Somerset, Hertfordshire, Middlesex, Surrey, and, I believe, Sussex. The range abroad is similar to that of T. batis.
The Poplar Lutestring (Palimpsestis or).
May be recognized in the typical form by the four-lined bands, "lutestrings," on the greyish, sometimes pink-tinged fore wings; the reniform and orbicular marks are often present although the first is generally obscure, and they never assume the similarity to figures noted in the last species (Plate 36, Figs. 7, 8). In Scotland the moths have a paler ground colour generally, var. scotica, Tutt; one from Ireland with ground colour pearly white and broad black "lutestrings" has been named var. gaelica, Kane. Hybrids from a cross pairing of this species with the last have been obtained by Mr. W. H. B. Fletcher. These specimens have the "lutestrings" of or, and the "figure of 80" characteristic of octogessima. Caterpillar yellowish green with a dark line along the middle of the back, and two black spots on the front edge of the ring next the yellowish brown head. It feeds on poplar, and hides between united leaves in the daytime; may be found from July to September or even later. Chrysalis, reddish brown, the surface minutely pitted, and spike pointed, and thickened at the base; in a brownish cocoon spun up between leaves. The moth emerges in June or July, and it comes freely to sugar, but like other members of this family is not always easy to box. It seems to occur in most places where poplar trees are well established; widely distributed over England, and found throughout Scotland even to the Shetland Isles. In Ireland it seems to be local and rare. Distribution abroad much as in the last species.
The Lesser Satin Moth (Palimpsestis duplaris).
Figs. 1, 2, on Plate 39, represent the typical southern form of this species. The fore wings are pale greyish with a whitish edged, broad, dark central band; two black dots on the outer edge of the band distinguish this species from the next. In Scotland and in Northern England the general colour is blackish or purplish grey (Fig. 3), and sometimes specimens more or less suffused with the darker colour are found in the southern half of England. Quite the darkest, almost black, form seems to occur in Cannock Chase, Staffordshire, and in Delamere Forest, Cheshire. The caterpillar is greenish; central area of the back green, margined on each side by an olive green, or brighter green, stripe; some black dots along the sides; head reddish brown marked with black. Feeds on birch, and may be found from August to October. It spins the leaves together for a shelter during the daytime, and comes out to feed at night, when it may be obtained by beating the boughs. Other food plants mentioned are alder, oak, and hazel. The pupa is of a dull reddish colour, in a slight cocoon between leaves.
Widely distributed throughout England and common in most woodlands, especially in the south and east; it ranges through Scotland to the Shetlands. In Ireland, where the moth has the ground colour silvery grey (var. argentea, Tutt), it has been obtained in many localities, from Donegal and Tyrone to Kerry and Cork.
The Satin Carpet (Palimpsestis fluctuosa).
In colour and general pattern this species (Plate 39, Fig. 4) is very similar to the last in its typical form. The points of distinction are, the slightly larger size, whiter ground colour, and the absence of the two black dots from the edge of the band. In August and September the caterpillar feeds, at night, on birch, and by day conceals itself between leaves. It is reddish or violet grey above, and pale ochreous-white beneath; the lines down the centre of the back and along the sides are darker; on the first ring there is a greenish-tinged yellow plate, and from this to the eleventh ring there are two series of black dots along the back. Head yellow-brown, blackened above; a black circle on each cheek. Chrysalis reddish-brown, in a cocoon among leaves either on the tree or on the ground. The moth emerges in June, and is distinctly local. Sometimes it may be disturbed from its resting place among the foliage; it becomes active on the wing at dusk for a short time; sugar does not seem to possess any great attraction for it, anyway it does not attend the feast prepared for Noctuæ so frequently as other members of this family. It is known to occur, chiefly in woods, in Kent, Surrey, Sussex, and Hampshire in the south; Essex and Suffolk in the east; also in Worcestershire (Wyre Forest), and Herefordshire; in the Barnsley and Sheffield districts of Yorkshire; and it has been reported from Cumberland. In Ireland it is rare and only recorded from Killarney, Kerry, and Sligo. Abroad it occurs in Central Europe, the range extending to Southern Scandinavia, and to South-east Russia.
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| Pl. 38. |
| 1. Frosted Green: caterpillar. |
| 2, 2a, 2b, 2c. Yellow Horned: egg, caterpillar, chrysalis and cocoon. |
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| Pl. 39. | |||
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| 9. Frosted Green Moth, male; 10 female. |
The Lesser Lutestring (Asphalia diluta).
The fore wings are whitish or greyish, and sometimes tinged with brown; crossed by two brownish bands. Variation is chiefly in the tint of the bands and also in their width and definition. In var. nubilata, which occurs in Yorkshire, the general colour of the fore wings is darker than normal, and there is a basal patch and three cross-bands of reddish or purplish brown (Plate 39, Figs. 5, 6).
Caterpillar, yellowish above and greyish beneath; a dusky line along the middle of the back, and one, dotted with black, low down on the sides; head dark brown, almost blackish. It feeds in May and June on oak, but only at night; it constructs a leafy chamber in which it sits tight during the day, and is not easily evicted unless its apartment is forcibly opened. The reddish chrysalis is enclosed in a flimsy cocoon between, or among, leaves. Although September is the month during which the moth usually emerges, it is sometimes seen earlier. It is so partial to sugar, that it may often be seen at an old patch before the new feast has been set out for the evening entertainment. The species is fairly well distributed throughout England and Wales, and most common in the south of the former country. It extends into Southern Scotland, but apparently does not occur in Ireland. Abroad it is found in Central Europe, Belgium, North Germany, North Italy, and North-east Asia Minor.
The Yellow Horned (Polyploca flavicornis).
In the South of England this species is greenish grey, sometimes speckled or dusted with darker grey; the reniform and orbicular marks are generally clear and distinct, but in some examples they are united and form a whitish blotch outlined in blackish; the cross lines are usually well defined, but in the dark grey dusted form are very obscure. Specimens from Scotland are generally larger, there is less green, if any, in the ground colour, and the markings are often more pronounced and brighter. This form is the var. scotica, Tutt, and may be more or less identical with the var. finmarchia, Schöyen, from Norway and Lapland (Fig. 7, Plate 39, shows the English form, and Fig. 8 the Scotch form).
The caterpillar is greenish, light olive green, or dark olive green above, and yellowish beneath; a line along the middle of the back is paler, and on each side there is a row of black spots and finely black-edged white dots; a line above the brownish outlined spiracles is yellowish: the head is yellow brown with blackish jaws and black mark on each cheek. It feeds in June and July on birch, preferring the foliage of bushes. During the daytime it resides in a leaf neatly folded in half; when quite young, the caterpillar then being blackish, a small leaf or just the turned-over edge of a large one answers its purpose. The chrysalis is reddish, enclosed in a flimsy cocoon among leaves, moss, or roots of grass, etc., sometimes just under the surface of the soil. The early stages are figured on Plate 38, Figs. 2-2c. The moth emerges in March or April of the year following pupation, as a rule, but it may remain in the chrysalis for two winters. It is often obtained in birch woods, or wherever there is a good growth of birch, by jarring the twigs and branches of birch upon which it rests during the day, or it may be found by searching the low bushes and underwood. Soon after dusk it is on the wing, and will then visit sugar and sallow bloom.
Generally distributed throughout Great Britain. In Ireland it appears to be very rare. Its range abroad, in the typical form, extends over Northern and Central Europe to North Italy and to South-east Russia.
The Frosted Green (Polyploca ridens).
This moth (Plate 39, Figs. 9, 10) is also on the wing early in the year, but although it is sometimes found on tree trunks in April or perhaps as late as the first week in May, it seems to be rarely obtained otherwise in the perfect state. It does not "come to sugar" often, if at all, and so far as is known, does not visit any of the usual natural attractions.
The ground colour of the fore wings varies from whitish to green, but in some specimens the general hue is olive or blackish green, and the markings then appear to be wavy whitish lines crossing the wings, one near the base, and the other before the outer margin.
The caterpillar (Plate 38, Fig. 1) is yellow above and rather greenish beneath; a greenish grey double stripe along the back is interrupted at the ring divisions; there are also white dots with black or blackish edges on the back and the sides; a yellow line along the spiracle area is shaded above and below with greenish grey; the head, which is notched on the crown, is yellowish, with a black mark on each cheek. It feeds, at night, on oak, from May to July; hiding by day on the underside of a leaf, a portion of which is folded over and secured with silk, to form a suitable retreat. These caterpillars respond more readily to the persuasive beating-stick than others of the group.
The species affects woodland localities in most of the southern counties of England, and it is also found in South Wales. Its range extends into the Eastern Counties and through the Midlands northward to Cumberland. It does not seem to have been noted from Scotland or Ireland. Abroad it is distributed over Central Europe and northward to Denmark and Livonia, and southward to South France and Andalusia.