The Moths of the British Isles Volume Ii Part 18

As a British insect, it has only been known since 1851, when the capture of a specimen in the neighbourhood of Bristol was recorded in _The Zoologist_.

Subsequently it transpired that the scene of capture was Durdham Down, Gloucestershire, and here it has been found annually, and in some plenty, among the bushes and low vegetation covering the ground in that rugged locality. Specimens have also been noted from Berkshire (Newbury), Bucks (Chalfont St. Peter), Dorset (Halstock), {117} and Norfolk (Thetford).

Possibly there are other localities in England, more especially in the west, where this species may be awaiting discovery.

THE SATIN WAVE (_Acidalia_ (_Ptychopoda_) _subsericeata_).

The wings of this species (Plate 45, Fig. 17) are glossy whitish, with a faint greyish, or sometimes yellow greyish, tinge; the cross lines are grey, oblique and straight on the fore wings, but the outer two on the hind wings are curved or bent.

Var. _mancuniata_, Knaggs, a local form found in Lancashire and Yorkshire, is rather more tinged with yellowish, the lines being distinct, and some more or less distinct dusky dots on the outer margin of the fore wings.

A blackish form, with white fringes, has been recorded from North Cornwall, where the species, in its usual form, has been noted as abundant.

The rough-looking caterpillar is pale greyish, inclining to reddish above; three black lines along the back, the central one slender, and the outer ones widening out towards each end. It feeds on knotgra.s.s, dandelion, chickweed, and other kinds of weeds, and will eat plum. Hatching in August, it hibernates, as a rule, and attains full growth in the following spring; but sometimes caterpillars feed up quickly, and produce moths the same year.

The moth, which is out in June and July, is partial to heathy ground, but not confined to heaths, as it has been met with in lanes bordered by pasture fields. Widely distributed throughout England and Wales, rare in Scotland, where it has only been recorded from the Solway. In Ireland it has been found commonly at Howth, near Dublin; and in the counties Cork and Waterford. {118}

PORTLAND RIBBON WAVE (_Acidalia_ (_Ptychopoda_) _degeneraria_)

This reddish-banded species (Plate 46, Fig. 1) is, so far as we know, only found, in Britain, in the Isle of Portland, Dorset, where it was first noted on June 24th, 1831. It will be seen that apart from its different colour, the bands in this moth are placed nearer the base of the wings than in _A. aversata_; on the fore wings the band is limited by the first and central lines, but sometimes it encroaches on the basal area; on the hind wings, it occupies more or less of the basal area, from the first line inwards; the front edge of the fore wings is also reddish.

The caterpillar is ridged along the sides of the roughened body, and tapers towards the slightly notched, blackish marked head; the general colour is reddish-ochreous, darker on the back of the middle rings, along which are three interrupted pale greyish ochreous lines, and dark V-shaped marks. The natural food plant is not known, but it may be reared from the egg on bramble, traveller's joy (_Clematis_), and, of course, knotgra.s.s and dandelion, both of these plants being generally acceptable to larvae of the Acidaliinae, as well as to those of many other species of Geometridae.

The moth is out in June and July in the open, but has been bred as early as June 2. Some of the caterpillars from eggs laid in June will feed up quickly, and produce moths in September; from these, other eggs may be obtained, the caterpillars from which will feed for a time and then hibernate; as also do the slow-growing individuals of the earlier hatching.

Abroad, this seems to be a Mediterranean species, ranging eastward through Asia Minor to parts of Central Asia; and northwards to Austro-Hungary, Castile, France, and West Central Germany.

[Ill.u.s.tration]

2 Pl. 46.

1. PORTLAND RIBBON WAVE.

2. PLAIN WAVE.

3-6. RIBAND WAVE.

7-10. SMALL FAN-FOOTED WAVE.

9, 12. SINGLE-DOTTED WAVE.

8, 11. TREBLE BROWN-SPOT.

13, 14. LACE BORDER.

[Ill.u.s.tration]

2 Pl. 47.

1, 1a. SINGLE-DOTTED WAVE: _eggs and caterpillar_.

2. RIBAND WAVE: _caterpillar_.

3, 3a. PLAIN WAVE: _eggs, caterpillar and chrysalis_.

{119}

THE PLAIN WAVE (_Acidalia_ (_Ptychopoda_) _inornata_).

Somewhat similar to the last in appearance, but without reddish bands, and front edging to the fore wings; the second or outer line of the fore wings is generally distinct, but the others, especially the central, are often obscure. This species, one example of which is shown on Plate 46, Fig. 2, may be distinguished from the plain form of _A. aversata_ by its generally smaller size and more silky appearance; the cross lines are less distinct, and the outer one of the fore wings is not indented below the front margin.

The eggs (Plate 47, Fig. 3a) are laid in strings of from 6-20; at least this is so in captivity. Like the eggs of other species in this genus that I have seen, they are at first whitish bone colour, changing to reddish.

They were laid in July, and most of the caterpillars that hatched from them attained the moth state in September; about one-third hibernated, but died off during the winter.

The much-wrinkled and rough-looking caterpillar is pale reddish brown, varying to greyish; the back with V-shaped marks, and a light coloured spot on rings 5 and 6. It feeds, from August to June, on dandelion, dock, and other weeds, also on sallow, bramble, heather, etc.

The moth is out in July, earlier or later in some seasons; it affects woods in which there is plenty of heather or bilberry, and may often be seen resting on tree trunks, especially those of the pine. It is on the wing in the evening, and is said to visit the sugar patch, as well as flowers growing in its haunts. Widely distributed over England and Scotland to Moray, but does not appear to have been noted in Wales. Reported from Kingstown, Killarney, and Londonderry in Ireland. {120}

THE RIBAND WAVE (_Acidalia_ (_Ptychopoda_) _aversata_).

There are two distinct colour forms, one is greyish white (ab. _spoliata_, Staudinger), and the other decidedly ochreous; the former is sometimes tinged with ochreous, and sometimes heavily sprinkled with dark grey. In the type form of _aversata_, the general colour is greyish white, and the s.p.a.ce between the central and outer lines of the fore wings, and that enclosed by the first and central of the hind wings, is more or less entirely filled up with dark grey inclining to blackish; occasionally the dark colour spreads beyond the outer line, and covers a large portion of the outer area. These bands also occur in the ochreous and intermediate colour forms. A specimen, bred in June by Mr. W. G. Sheldon, from a caterpillar found on a fence at West Wickham in May, had the wings and abdomen black, but the head, thorax, a.n.a.l tuft, and fringes of the wings were normal. (Plate 46, Figs. 3-6.)

The caterpillar (Plate 47, Fig. 2; from coloured drawing by Mr. Sich) is much wrinkled, rather thickened behind, and tapers gradually towards the small, black-flecked head; the general colour is brownish, merging into ochreous on the hinder rings; a darker brown shade along the back, interrupted on the middle rings by V-shaped marks, encloses a slender whitish line, and there is a whitish spot on ring eight; a wavy pale ochreous line low down along the sides. (Adapted from Fenn.) It feeds on dandelion, dock, primrose, bedstraw, knotgra.s.s, and many other low-growing plants; after hibernation, from April to May, it will thrive on the young growth of sallow, birch, hawthorn, etc. It will sometimes feed up and reach the moth state in August or September.

The moth flies in June and July, and is generally distributed; but in Scotland does not seem to have been observed north of Moray. {121}

SMALL FAN-FOOTED WAVE (_Acidalia_ (_Ptychopoda_) _bisetata_).

One form (Plate 46, Fig. 10) has whitish wings, with a deep, dark-grey border on the outer area of all the wings; this border is traversed by a whitish, wavy line (ab. _fimbriolata_, Stephens). Another form (Plate 46, Fig. 7) is more or less typical, and in this it will be noted that the marginal borders are much paler, and are broken up into bandlets. Between these two forms there are modifications, and sometimes a greyish shade spreads over all the wings.

The caterpillar is long and slender, with a somewhat flattened appearance, and gradually tapered towards the notched head; the general colour of the roughened body is greyish brown, the middle ring divisions, and V-shaped marks on the back, are blackish or dark brown; there is also a double dark-brown line along the back, not always distinct. It feeds, from August to May, on a variety of low-growing plants, and is partial to withered leaves, especially those of bramble and dandelion. The moth is out in June and July, and is often common, and pretty generally distributed throughout our islands, except that it seems not to have been noted north of Moray, in Scotland.

Abroad, the range extends to East Siberia and Amurland.

THE SINGLE DOTTED WAVE (_Acidalia_ (_Ptychopoda_) _dimidiata_).

The most noticeable feature in this whity brown moth (Plate 47, Figs. 9 and 12), sometimes known as _scutulata_, are the larger dots at the costal end of the dotted cross lines, and the blackish or dark-brown chain-like mark on the lower part of the outer marginal area of the fore wings; the latter is sometimes obscured in a cloud of its own colour. {122}

Eggs (Plate 47, Fig. 1a), laid in a batch on a dried leaf of dandelion, were whitish at first, but turned reddish later.

The elongated and somewhat flattened caterpillar (figured on Plate 47, Fig.

1, from a coloured drawing by Mr. Sich) is ochreous, with brown lines on the back, the central one double, and interrupted on the middle rings, upon which are oblique pale-brown dashes. It feeds, from September to April, on beaked parsley (_Anthriscus sylvestris_), burnet saxifrage (_Pimpinella_), etc., and may be reared on withered leaves of dandelion and other weeds.

The moth is out in June and July, and in northern localities in August.

Generally distributed, and often common.

TREBLE BROWN SPOT (_Acidalia_ (_Ptychopoda_) _trigeminata_).

This species (Plate 46, Figs. 8, 11) is similar to the last, but generally rather larger and somewhat paler; the front edge of the fore wings is marked with blackish or dark purplish grey, and there is a band of the same colour on the outer marginal area; the inner edge of this band is formed by the second line, and the outer edge is wavy, interrupted above the middle, and sometimes below also.

The rough and rather flattened caterpillar tapers towards the head; in colour it is dusky brown. The markings comprise interrupted black lines and V-shaped blackish marks on the back. Buckler states that this caterpillar may be distinguished from those of its nearest allies by having a rather long, dingy ochreous bristle from each of the raised dots; these bristles, which are of the same thickness throughout, curve forwards on all rings to the ninth, and on the other three backwards. It feeds, from September to April, on various low-growing plants, ivy, birch, etc. If kept warm, it is said that whole broods will attain the moth state in July or August; this may happen sometimes, but in my experience only a few individuals have obliged in this way. The moth is another inhabitant of the hedgerow and the bushy wood-border, where it may be disturbed in the daytime during late May and June. It flies in the evening, and will visit light, and occasionally the sugar patch. Always a local species, but not uncommon in its special haunts in Kent, Surrey, Wiltshire, Ess.e.x, and Suffolk; it is also found more or less frequently in Suss.e.x, Hampshire, Dorsetshire, Gloucestershire, Herefordshire and Worcestershire. In Scotland, it is reported as scarce in Renfrew; and Kane notes that it does not occur in Ireland.

[Ill.u.s.tration]

2 Pl. 48.

1. LEAST CARPET: _caterpillar_.

2, 2a, 2b. SMALL BLOOD-VEIN: _egg enlarged, caterpillar and chrysalis_.

[Ill.u.s.tration]

2 Pl. 49.

1, 2. CREAM WAVE.