Volume Ii Part 50 (1/2)
The rather long and somewhat oval fore wings of this species (Plate 137, Figs. 8, 9) are brownish grey, inclining to purplish grey; the two cross lines are blackish, edged with whitish, but generally indistinct; when the lines are well defined, the enclosed central area is sometimes darker than the other parts of the wings; there is a black central dot, and occasionally there is a well-marked dusky central shade. Hind wings, whitish, more or less tinged with smoky grey; frequently there is a dusky, curved line beyond the middle, and this is sometimes outwardly edged with whitish.
The caterpillar is greyish brown, dotted with black, and marked on the back and sides with reddish brown. When at rest on the twigs of its food plant, heather or ling (_Calluna vulgaris_), this caterpillar agrees so well with its surroundings that it is not at all easy to see; at least, we may see it, but fail to distinguish it from the twigs of the plant. It may be obtained in June and July, and again in the autumn. (Figured on Plate 140, after Hofmann.)
The first flight of the moth occurs in April and May; the second in August, but specimens of the later generation are usually small in size and in number, as compared with those of the early brood.
In Britain, this species has so far only been found on the heaths of Kent, Surrey, Suss.e.x, Hamps.h.i.+re, Dorsets.h.i.+re, Somersets.h.i.+re, Berks.h.i.+re, and Suffolk; in all these counties it is more or less local, but it abounds in some of its haunts. It has been recorded from Hereford, and Edwards states that it occurs rarely in the Malvern district of Worcesters.h.i.+re.
[Ill.u.s.tration]
2 Pl. 138.
1. SATIN CARPET: _egg and caterpillar_.
2. SQUARE SPOT: _eggs_.
3. THE ENGRAILED: _caterpillar and chrysalis_.
[Ill.u.s.tration]
2 Pl. 139.
1-3. ANNULET.
4, 5. SCOTCH ANNULET.
6, 7. BLACK MOUNTAIN MOTH.
{319}
THE ANNULET (_Gnophos_ (_Sciadion_) _obscurata_).
In a general way, all the grey specimens of this species are referable to the type form _obscurata_, Schiffermuller; the true type, however, appears to be rare in Britain, even if it occurs at all. It is, perhaps, best represented by well-marked dark specimens from limestone districts, or the lighter ones from peaty ground. At Folkestone and in other chalky localities on the Kentish coast, the bulk of the specimens are pale grey inclining to whitish, usually with the black cross lines showing more or less clearly. Sometimes the lines are obscured by heavy freckling (ab.
_woodiata_, Prout); not infrequently, at Folkestone chiefly, the inner and outer areas are pale, more or less free of freckling, but the central area, defined by black lines, is densely freckled; this is the banded form (ab.
_fasciata_, Prout). A form occurs on the chalk hills at Lewes in Suss.e.x, in which the wings are almost white, without freckling, but with distinct black lines and rings (ab. _calceata_, Staudinger); a modification of this whitish form from Lewes has been described by Prout as ab. _mundata_, ”Almost pure whitish, with virtually no markings, excepting the annulets.”
On heaths in Surrey and Hamps.h.i.+re, and on the mountains of Aberdeen and Perths.h.i.+re, a blackish form occurs (ab. _obscuriorata_, Prout = _obscuraria_, Hubner, 146); and sometimes specimens are found in which the wings are of ”an intense and almost uniform black” (ab. _saturata_, Prout).
In Devons.h.i.+re and Cornwall, the species is darkish grey inclining to brownish (ab. _anthracinaria_, Esper); whilst on the coasts of North Devon and Wales it is of a slaty grey, more or less tinged with brown, and almost without markings; the Welsh specimens are large, and the wings are rather s.h.i.+ning (ab. _uniformata_, Prout). A form, which I have not seen, of ”a sandy or reddish colour” is referred by Prout (_Trans. City of Lond. Ent.
Soc._, 1903, p. 39) to ab. _argillacearia_, Staudinger; it {320} occurs in sandstone localities. (Plate 84, Figs. 1, Folkestone; 2, New Forest; 3, Lewes.)
The rather rough and dumpy caterpillar is dark greyish brown above, inclining to purplish brown beneath; the raised dots are capped with white, and there is a pair of white-capped warts on the last ring (adapted from Barrett). It feeds on rock rose (_Helianthemum_), cinquefoil (_Potentilla_), salad burnet (_Poterium_), etc.; or the larvae may be reared on groundsel, chickweed, and strawberry, both wild and cultivated: September to May. (Plate 140, Fig. 2.)
Mr. A. J. Scollick kindly gave me some eggs, laid by a female taken in Surrey; they were yellowish green at first, but changed to pale brownish.
The caterpillars hatched and seemed to thrive on groundsel, but they died during the winter.
The moth is out in July and August, and is widely distributed in England, but except that it occurs in Surrey, Berks.h.i.+re, Herefords.h.i.+re, and Worcesters.h.i.+re, it seems to prefer the seaboard counties, and in them chiefly affects localities near the sea. It is found in Wales, and in Scotland up to Moray; but in both these countries and also in Ireland it is most frequent on the coast.
SCOTCH ANNULET (_Gnophos myrtillata_).
This species (Plate 139, Figs. 4 [male], 5 [female]) was introduced, as a species new to Britain, by Curtis, who described and figured it as _Charissa operaria_ in 1826, from specimens captured in Scotland.
Subsequently, it was found to be the _obfuscaria_, of Hubner, and also the _obfuscata_ of the Vienna Catalogue (1776). The latter, however, being only a bare name without description, was not generally accepted, although, if valid, it would be prior to Hubner. Still later the species was ascertained to be the _myrtillata_ of Thunberg (1792), and as this name is much earlier than _obfuscaria_ it is here adopted. As a matter of fact, both names are in use, as that of Hubner applies to our ashy grey form of the species, whilst that given by Thunberg belongs to the typical fuscous grey form.
[Ill.u.s.tration]
2 Pl. 140.
1. HORSE CHESTNUT: _caterpillar_.