The Moths of the British Isles Volume Ii Part 17

Two forms of this pretty little species (known also as _auroraria_) are shown on Plate 45. Fig. 1 represents the more usual form, but between this and the almost entirely purple variety (Fig. 4), which occurs chiefly in the north, there are various modifications. Then again, especially in the south of England, there is a tendency to become entirely yellow, the purple, inclining to crimson in such specimens, being confined to the front margin and cross lines on the fore wings, and a narrow band on the outer margin of all the wings.

The caterpillar is pale brownish, inclining to ochreous at each end, marked with irregular blackish lines on the back, and dots and streaks on the sides. Its natural food plant seems to be unknown, but when reared from the egg the caterpillar will eat knotgra.s.s, and sometimes a few will feed up and attain the moth state the same year. August to May.

The moth occurs in late June and in July, and frequents fens, boggy heaths, and mosses. Although odd specimens may, occasionally, be flushed during the day, the collector will need to be up early in the morning if he would see this species on the wing, as it seems to fly most freely about sunrise. The New Forest in Hamps.h.i.+re is a noted district for it, as also are Ranworth, Horning, etc., in Norfolk, and Witherslack in Westmoreland. In Ireland, it is found in counties Galway, Kerry, and Mayo.

Abroad, the range extends to Amurland, China, Corea, and j.a.pan.

WEAVER'S WAVE (_Acidalia_ (_Ptychopoda_) _contiguaria_).

The earliest known British specimen of this species (Plate 45, Figs. 2 and 5) was taken in North Wales by Weaver, in 1855, {110} and was figured and described in _The Entomologist's Annual_ for 1856 as _Dosithea eburnata_, Wocke. About seven years later Greening captured a female specimen, and he subsequently reared the insect, when it became known as "Greening's Pug."

Still later, about 1875, the English name was changed to "Capper's Acidalia."

Fortunately, the species seems not difficult to rear from the egg, otherwise specimens in collections would be not only very limited in number, but frequently very indifferent in condition.

In colour the moth is whity brown, more or less dusted or clouded with dark grey; except in the darker forms, three irregular black lines on the fore wings, and two on the hind wings, are clearly seen. It flies at dusk in June and July, and sits by day on lichen-covered rocks.

The caterpillar is pale ochreous brown, with irregular dark brown lines. It feeds on ling (_Calluna_) and crowberry (_Empetrum_) from September to May; but when eggs are obtained, the caterpillar hatching from them may be kept on chickweed, knotgra.s.s, etc., and the moth be reared the same year.

Mr. R. Tait records the finding of ten caterpillars on navelwort (_Cotyledon_) growing among heather in a very sheltered corner among rocks in North Wales, at Easter, 1906. He also notes that moths reared in captivity pair readily.

The British localities, all in North Wales, are Aber, Bangor, Barmouth, Bettws-y-coed, Conway, Dolgelly, Lanfairfechan, and Penmaenmawr.

THE LEAST CARPET (_Acidalia_ (_Ptychopoda_) _rusticata_).

The whitish fore wings of this species (Plate 45, Figs. 3 and 6) are crossed by a blackish central band, and there is a blackish patch at the base of the wings, with an extension along the front margin, almost or quite to the central band; the hind wings have a central dot, and three or four dark grey wavy lines, the s.p.a.ce between the first and second darkened, and appearing to be a continuation of the fore wing band. The thick set, pale ochreous-brown, or grey-brown, caterpillar (Plate 48, Fig. 1, drawn from a skin) has three more or less distinct pale lines along the back, and a series of darker diamonds along the central area; head, brown. In the open, its food probably consists of decaying or withered leaves, but when treated in captivity it will eat and thrive upon growing knotgra.s.s, groundsel, dandelion, etc. August to May. Mr. Mera mentions that some caterpillars he reared on dandelion produced moths that were larger in size than most captured specimens.

[Ill.u.s.tration]

2 Pl. 44.

1. SMALL GRa.s.s EMERALD: _caterpillar_.

2. LITTLE EMERALD: _caterpillar_.

3, 3a. SMALL EMERALD: _caterpillar, chrysalis and coc.o.o.n_.

[Ill.u.s.tration]

2 Pl. 45.

1, 4. PURPLE BORDERED GOLD.

2, 5. WEAVER'S WAVE.

3, 6. LEAST CARPET.

7, 10. RUSTY WAVE.

8, 11, 14. SMALL DUSTY WAVE.

9, 12. DOTTED BORDER WAVE.

13. SILKY WAVE.

15, 18. DWARF CREAM WAVE.

16. ISLE OF WIGHT WAVE.

17. SATIN WAVE.

{111} The moth is out in July, and specimens have been bred in September from eggs laid in July of the same year. To obtain this species, a journey will have to be made to one or other of its special haunts in Kent, lying between Greenhithe and Sheerness. Other localities from which it has been recorded are Kingsdown, Dover, Folkestone (Kent); Brighton, Lewes, West Horsham (Suss.e.x); Isle of Portland (Dorset); Rame Head, Torquay (Devon); and single specimens have been reported from Stowmarket and Felixstowe (Suffolk).

THE RUSTY WAVE (_Acidalia_ (_Ptychopoda_) _herbariata_).

In _The Entomologists Annual_ for 1856, two species of _Acidalia_ were brought forward as new to the British list. One of these has been referred to under _A. contiguaria_, the other was the present species, which at the time was wrongly referred to _circuitaria_, Hubner. The specimens depicted on Plate 45, Figs. 7 and 10, are of continental origin.

Although other specimens were then known to exist in at least two British collections, the first recorded example was that mentioned above. This was captured in Bloomsbury Street, {112} London. In June, 1868, three or four examples were found in a herbalist's shop in Holborn; one occurred on a shop window in Oxford Street in 1873; one example was taken from a door-post in Cannon Street, July 21, 1879; and two others have been noted from the same street, but dates were not given. The latest record, that of a specimen on July 21, 1898, in a shop in Southampton Row, Bloomsbury, closes the list; it then appears that all the British specimens known to us have been taken in London.

The eggs are laid on dry or withered plants, upon which the long brownish or greenish caterpillars feed throughout the autumn, winter, and following spring. They pupate towards mid-May, and the moths appear in June and July.

According to Guenee, caterpillars seem to have been found only in herb or drug stores, and the moths occur in gardens and houses in July and August.

THE SMALL DUSTY WAVE (_Acidalia_ (_Ptychopoda_) _virgularia_).

In most parts of the southern half of England this species, of which three specimens are shown on Plate 45, Figs. 8, 11, 14, is more or less common, and is often to be seen on garden walls, pales, and other kinds of fences.

Although apparently infrequent in the Midlands, it has been recorded as common at Rugely in Staffords.h.i.+re; in several parts of Ches.h.i.+re it is not uncommon, and its distribution is known to extend to Northumberland.

Possibly the species is more widely spread over England than the records show it to be. In Wales, it has been found in the North; in Scotland, it occurs locally from Berwick to Aberdeen; and it is doubtfully recorded from Ireland. The long, thin caterpillar is ochreous-brown, with a pale stripe on each side. It feeds on the leaves of various low plants, and seems, at times, to like its food best when withered. Some {113} that I reared from eggs deposited in September, 1904, fed for a time on fresh dandelion, but on the approach of winter they apparently ceased feeding, and were allowed to remain in the box with the food last supplied. In March it was found that they had been, and were then, eating the old provender. Some fresh dandelion was added, but this was not touched until all the old had been consumed. The same thing was repeated until the caterpillars were nearly full grown, when the fresh food was eaten as well as the stale. The moths resulting from them emerged during the last week in April, 1905, and were all well above the average size, and considerably larger than the female parent. One example is represented by Fig. 11 on the plate.

There are certainly two generations of the moth during the year; in some years possibly more.

DOTTED BORDER WAVE (_Acidalia_ (_Ptychopoda_) _straminata_).

In its ordinary form this moth (Plate 45, Figs. 9, 12) is greyish white, sometimes with a tinge of brown, especially on the fore wings; the darker cross lines are slightly wavy; each wing has a central black dot, and there is a more or less distinct series of black dots on their outer margins. Ab.

_circellata_, Guenee (Plate 61, Fig. 3), has the first and second lines of the fore wings strongly defined and deep brown, and the first is united with the central shade above the inner margin; the corresponding lines on the hind wings are also deep brown. This form, which occurs on the Lancas.h.i.+re and Ches.h.i.+re mosses, and is known as the Obscure Wave, has been considered a distinct species, but it is connected with typical _straminata_ by intermediate aberrations which occur together with _circellata_ and the ordinary form on the same ground. Similar intergrades also occur in the New Forest, Hamps.h.i.+re, the Dover district of Kent, and probably elsewhere. {114}

The rough-looking, long and slender caterpillar is pale greyish, with a black-edged pale line along the middle of the back, the black edging interrupted on rings 4-9; on each side of the central line, and lower down along the sides, are other black streaks; head, notched on the crown, and marked with brown.

Some eggs laid August 8th, hatched on September 1st; the infant caterpillars were long and thread-like, the colour was black, and there was a whitish stripe low down along the sides. They would not feed on knotgra.s.s and other plants offered to them, and I failed to rear them. Moths have, however, been bred, as a second generation, in the autumn from caterpillars reared from the egg, on bramble and knotgra.s.s.

The moth occurs in July and August on bush-sprinkled heaths, or heathy ground, where it may be disturbed from the herbage in the daytime, or netted as it flies in the evening. South of England from Kent to Dorset; also in Berks.h.i.+re, Ches.h.i.+re (one specimen, Whitegate Heath, 1901, one ab.

_circellata_ in Delamere Forest, July, 1903); Yorks.h.i.+re (Thorne Moor, and rather plentiful on Skipton Common in 1900 and subsequent years; ab.

_circellata_ also occurred).

THE DWARF CREAM WAVE (_Acidalia_ (_Ptychopoda_) _interjectaria_).

This moth (Plate 45, Figs. 15, 18) is said to be referable to _fuscovenosa_, Goeze, and as this is an earlier name than _interjectaria_, Guenee, it may have to be adopted. For many years it was known in England as _osseata_, and was described by Haworth, Stephens, and others, under this name. It is also the _dilutaria_ of some authors, but not of Hubner.

Hubner's dilutaria is considered by some writers to be the _holosericata_ of Duponchel, and therefore an earlier name for the species generally known by the latter name. {115}

The present species, to which Haworth gave the English name here used, is whitish straw-coloured, and silky in appearance; the wings have a central black dot and four or five dusky cross lines, some of which are more distinct than others; the front edge of the fore wings is tinged with reddish brown, in which is often a dark dot at the ends of the first and central lines; a series of linear blackish dots at the base of the fringes, most distinct on the fore wings.

The somewhat stumpy caterpillar is dull smoky brown, marbled and variegated with ochreous, the darker colour most in evidence in front, and the ochreous behind; an ochreous line along the middle of the back, and one along the region of the spiracles; white spots on rings 5-7. (Adapted from Porritt.) It feeds from August to April on dandelion and other low-growing plants, and especially on the withered leaves. The moth occurs among weeds growing on banks, and hedgerows, and the outskirts of woods, in greater or lesser plenty throughout the South of England; but it becomes local, and more or less rare in the north of the country. In Scotland it is said to be uncommon in Clydesdale, but has not been noted from Ireland, or from Wales.

ISLE OF WIGHT WAVE (_Acidalia_ (_Ptychopoda_) _humiliata_).

This species (Plate 45, Fig. 16) is the _osseata_ of Fabricius, but not of Haworth and other British authors. It is very similar in general appearance to the species last considered, but the wings are somewhat less ample, and rather yellower in tint. It is most readily recognised, however, by the distinctly reddish stripe on the front edge of the fore wings. Previous to 1891, when specimens were obtained by Mr. A. J. Hodges in the Isle of Wight, the species was not certainly known to be an inhabitant of the British Isles, although it seems to have been represented in many collections. The {116} insect is still found by those who know where to look for it on the sea cliffs of its island home, but so far as appears to be known at present, it does not occur in any other part of Britain. For this reason, it does not seem desirable to indicate the exact locality more definitely; but it may be added that the moth flies in July.

SILKY WAVE (_Acidalia_ (_Ptychopoda_) _holosericata_).

Somewhat similar to A. _interjectaria_, but tinged with pale brown, and even more glossy; the front edge of the fore wings is of the general coloration, and the only markings on the wings are darker cross lines, the third on the fore wings, and the second on the hind wings, being the most distinct. (Plate 45, Fig. 13.)

The rough and rather stumpy caterpillar tapers towards the small notched head; general colour dusky reddish-brown, a pale line along the middle of the back, finely edged with black. It feeds from August to May on rock rose (_Helianthemum_), eating the withered and even mouldy leaves. Will eat knotgra.s.s, and, no doubt, dandelion also.

Here, again, we have an ancient name brought forward to supplant that which the species has borne for years, and by which it is well known to entomologists. As I am not quite certain that Hubner's (Fig. 100) _dilataria_ does represent this species, Duponchel's name is here retained.