The Moths of the British Isles Volume Ii Part 52

The range abroad extends to East Siberia and Amurland.

YELLOW BELLE (_Aspilates ochrearia_).

As will be seen from Fig. 5 [female] on Plate 144, this species differs from the last in its yellower colour and rather smaller size; the fore wings have two cross bands, generally well defined, but in the male they are sometimes very faint and slender, and specimens have been recorded in which the bands were missing.

The roughened caterpillar, figured on Plate 142, from a coloured drawing by Mr. A. Sich, is pale ochreous brown, lined and striped with darker brown.

It feeds on wild carrot, plantain, {332} hawks'-beard, etc., and will thrive on knot-gra.s.s. There are two broods, one feeding in the spring, after hibernation; and the other in June and July, sometimes later. The first generation of moths flies in May and June, and the second in August and early September. The species occurs in all the southern seaboard counties of England from Kent to Cornwall, frequenting the downs and rough fields near the coast; also in the Sandbreck district of the eastern counties. It occurs in South Wales; and odd specimens have been reported from Ches.h.i.+re (Delamere), and from c.u.mberland.

The range abroad extends to North-west Africa and Asia Minor.

GRa.s.s WAVE (_Perconia_ (_Aspilates_) _strigillaria_).

A male and a female of this species are depicted on Plate 144, Figs. 7 [male] and 8 [female]. There is variation in the amount of dark speckling on the wings, and in the number and width of the cross markings; sometimes the first and second on the fore wings are united throughout their length, or towards the inner margin; coupled with this there is sometimes considerable increase in the width of the first cross marking of the hind wings. A rare variety in Britain is ab. _grisearia_, Staudinger, which is of an almost uniform greyish or greyish-brown colour, with the markings obscured.

The caterpillar is purplish grey, marked with paler and darker; two warts on the back of rings 7-10, the middle pair the largest and most prominent.

It feeds on ling, heath, broom, and the flowers of gorse or furze, and is best obtained in the spring after hibernation.

[Ill.u.s.tration]

2 Pl. 144.

1, 2. GREY SCALLOPED BAR.

3. BLACK-VEINED.

4, 5. YELLOW BELLE.

6. STRAW BELLE.

7, 8. GRa.s.s WAVE.

[Ill.u.s.tration]

2 Pl. 145.

1. TRANSPARENT BURNET: _caterpillar_.

2, 2a. NARROW-BORDERED FIVE-SPOT BURNET: _caterpillar, chrysalis and coc.o.o.n_.

3, 3a. FIVE-SPOT BURNET: _caterpillar and coc.o.o.n_.

4. SIX-SPOT BURNET: _caterpillar_.

5. FORESTER: _caterpillar_.

{333} The moth, which is out in June and July, occurs on most of the heaths and moors throughout England; apparently commoner and more generally distributed in the south than in the north; but it seems to be rare on the eastern side of the country altogether. From Ches.h.i.+re it spreads into Flint and Denbigh, North Wales. In Scotland, it is found in Roxburgh (Bellion Moor), Clydesdale (local, but common), and northwards to Ross. It is found on the boggy heaths of Ireland, and Kane states that it is abundant where it occurs.

The range abroad extends to Scandinavia and eastward to Asia Minor.

ZYGaeNIDae.

The moths belonging to this family are popularly known in Britain as Burnets and Foresters. Of the former seven kinds occur in the British Isles, and of the latter there are only three species.

All the species live in colonies, so that when a specimen is seen or captured others may be expected to occur on, or somewhere around, the same spot. The caterpillars bear a close resemblance to each other, and are not always easily distinguished.

Over thirty species of _Zygaena_ are found in Europe, and about thirty-six more have been described from other parts of the Palaearctic Region. There are at least twenty-five Palaearctic species referred to the genus Ino, and about ten of these are European.

By most authors _filipendulae_ is regarded as the type of the genus _Zygaena_, Fabricius; but others refer this species, and its allies, to the genus _Anthrocera_, Scopoli, using the Fabrician genus for _phegea_, Linnaeus. The latter species and its allies are perhaps more frequently referred to _Syntomis_, Ochsenheimer, the typical genus of the family Syntomidae, the systematic position of which is near the Arctiidae. It may be added that _S. phegea_, and also _Naclia ancilla_, have been reported as British. There does not seem, however, to be any reason to suppose that the occurrence of either species in Britain could be other than accidental.

{334}

THE TRANSPARENT BURNET (_Zygaena purpuralis_).

Two Welsh specimens are depicted on Plate 146, Figs. 1 and 2; these are of the typical form. A rare aberration has the spots and the hind wings more or less suffused with blackish (ab. _obscura_, Tutt), but a still rarer variety has the crimson of spots and hind wings replaced by yellow (ab.

_lutescens_, Tutt).

Newman in 1861 referred an Irish specimen to _achilleae_, but a little later, after seeing other examples, in the same year he changed the name to _nubiginea_. Birchall (_Ent. Mo. Mag._, iii. pt. i.) figured four forms of the species from Ireland; his _minos_ (Figs. 5a and 5b) seems to represent two modifications of ab. _interrupta_, Staudinger, in which form the red blotches are widely separated or interrupted by the ground colour; and his _nubigena_ is made up of more or less typical _purpuralis_ (Fig. 6a), and a variety (Fig. 6b), with red marks between the lower and central blotches.

The caterpillar (Plate 145, Fig. 1) is dark green inclining to olive above and paler below; the spots are black (outer row) and yellow (inner row); the line along the back is obscure whitish; hairs, whitish. It feeds on thyme and burnet saxifrage (_Pimpinella_). _Trifolium_ and _Lotus_ have also been given among other food plants. In late summer, and after hibernation, in the spring. The moth flies in June, and is locally common in Ireland (Clare and Galway), Wales (Abersoch), and Scotland (Oban, Loch Etive). It has been reported from Tintagel, Cornwall, and possibly, as suggested by Tutt, these Cornish specimens may turn out to be _Z.

achilleae_, the latest addition to our small band of Burnets. Perhaps the Scottish specimens recorded as _purpuralis_, or at least some of them, may prove to be _achilleae_.

This species was figured by Brunnich, in 1763, as _purpuralis_, and authorities are now agreed that this name must be adopted in place of _pilosellae_, Esper (1781), or _minos_, Fuessly (1782). {335}

SCOTCH OR MOUNTAIN BURNET (_Zygaena exulans_).

This semi-transparent and rather greyish moth has five reddish spots on the fore wings. (Plate 146, Fig. 3.) So far as concerns the British Isles it is only known to occur in Aberdeens.h.i.+re, where it was discovered on the mountains at Braemar in July, 1871, and where it may be still found by those who are acquainted with the situation of its lofty haunts. The late Dr. Buchanan White named the Scottish form _subochracea_, but others consider that it is not readily separable from _vanadis_, Dalman, which in turn is said by Tutt to be pretty much the same form of the species as that described as the type _exulans_, Hochenwarth.

The caterpillar is dark green above, and paler below; two velvety black stripes on the back, each stripe interrupted by yellow spots; warts with black hairs; head, black. It feeds on _Silene acaulis_, cyphel (_Arenaria cherleria = Cherleria sedoides_), clover, trefoils, _Azalea proc.u.mbens_, etc.; has been known to eat dock and knot-gra.s.s: August to June. The coc.o.o.n has been found on a stem of crowberry (_Empetrum_), and on heath and gra.s.s stems. The moth is out in July, and, like the rest of its kindred, delights in the suns.h.i.+ne.

_Zygaena achilleae_.

A specimen of this species, quite recently introduced as British, has been kindly lent by Mr. B. Adkin. It was taken, with others, in the vicinity of Oban, Argylls.h.i.+re. Mr. Sheldon informs me that he believes that a worn Zygaenid he captured in 1898, in the Glencoe district, was this species.

On Plate 1, with the Scottish example (Fig. 2) referred to, is also shown a specimen from the continent (Fig. 3), and it will be noted that the former is very like the latter. In some {336} respects this species is not unlike some confluent-spot forms of _filipendulae_, but it is a more slender-looking insect, and the body is more hairy. Further, the upper basal spot of the fore wings is lengthened almost to the upper spot of the middle pair, and the fifth and sixth spots together form an almost oval mark. Both specimens depicted seem to be referable to var. _viciae_, Hubner.

In the typical forms the spots are larger. A yellow form ab. _flava_, Oberthur, is known on the continent.

The caterpillar, after Hofmann, is figured on Plate 1, Fig. 5. It is said to feed on _Astragalus_ and _Coronilla_.

NEW FOREST BURNET (_Zygaena meliloti_).

Two examples of this, normally, five-spotted little species are shown on Plate 146, Figs. 4 [male], 5 [female]; a variety, referable to ab.

_confusa_, Staudinger (spots run together forming streaks somewhat as in _purpuralis_), is depicted in Plate 148, Fig. 1. Occasionally a sixth spot is in evidence (ab. _s.e.xpunctata_, Tutt). A form in which the body has a red belt is known abroad as ab. _stentzii_, Freyer, and examples having traces of this belt have been recorded from the New Forest, which, it may be added, is the only locality in Britain producing this species.

The caterpillar is of a dull pale greenish colour, with numerous black speckles; three whitish lines on the back, the central one greenish tinged and broader than the others, which are interrupted on each ring by a yellow spot; between the lines is a series of black dots, one on the outer edge of each ring; hairs, from greenish warts, white and short; head, black, dotted with white. It feeds on bird's-foot trefoil (_Lotus corniculatus_), and other trefoils and clovers: August to May. Sometimes the caterpillars do not complete growth until they have pa.s.sed two winters in hibernation. The coc.o.o.n, which is yellow or yellowish white, has been found on a gra.s.s stem, but {337} it is generally placed so low down among herbage that it seems to be rarely detected.

The moth is out in June and early July.

As previously stated the only part of Britain that the species inhabits is the New Forest, Hamps.h.i.+re. Here it was first met with in Stubby Copse, about 1869, but was apparently not distinguished from _Z. trifolii_ until 1872. It is now less frequent in its old haunt than formerly, although it still occurs there; in other spots around, I believe, it is not uncommon in some years.

Some authorities refer this species to _viciae_, Schranck.

FIVE-SPOT BURNET (_Zygaena trifolii_).

Four specimens of this species are portrayed on Plate 146. In the typical form (Figs. 7 [male], 8 [female]) the central pair of crimson spots are united and often form a large blotch; ab. _orobi_, Hubner (Figs. 6 [male], 9 [female]), has the spots placed well apart. Other more or less frequent aberrations are depicted by Mr. Horace Knight on Plate 148 where Fig. 2 represents ab. _glycirrhizae_, Hubner (spots 3, 4, and 5 united); Fig. 3, ab. _basalis_, Selys (spots 3 and 4 united with the basal pair); and Fig.

4, ab. _minoides_, Selys (all the spots united, forming an irregular patch). An extreme development of the last-mentioned form has been named ab. _extrema_, Tutt (see _Entom._ xxix., p. 341, Fig. 2). Specimens with a sixth spot as in _Z. filipendulae_ have been occasionally recorded, and an example with the lower spot of the central pair absent has been taken in West Suss.e.x by Mr. W. M. Christy, who has also obtained a number of specimens of a yellow form (ab. _lutescens_, c.o.c.kerell) in the same locality. The yellow form is shown on Plate 148, Fig. 5. Some of the yellow aberrations also exhibit variation in the spots pretty much as in the ordinary form. In some localities, especially marshy ones, the spots on {338} the fore wings and the hind wings are occasionally dull orange; and I have noted specimens in the Weybridge district, Surrey, with the spots on the fore wings of a pinky ochreous colour, whilst the hind wings were of the usual crimson. Such "aberrations" as those last mentioned probably result from weather exposure. In 1899, Mr. G. B. Corbin recorded the capture, near Ringwood, Hants, of a specimen which had the spots on the fore wings and the red of the hind wings darkened over with dull smoky black, so that the insect when seen at a distance seemed to be wholly black. Dr. Hodgson has recently obtained several of these melanic specimens in Suss.e.x. A form with the spots and hind wings suffused with brownish has been named ab. _obscura_, Oberthur.

With regard to six-spot examples referred to this species, I am inclined to suppose that they may be the offspring of a chance pairing of _trifolii_ and _filipendulae_. That such crossing does occur in nature I have evidence, as on one occasion I found four mixed pairs, the male being _trifolii_ in each case, and the female typical _filipendulae_. This was in the Weybridge district, where I had come across a colony of the latter species and was closely examining the specimens for aberrations.

The caterpillar (Plate 145, Fig. 3) is green inclining to yellowish and to bluish, with black marks on the back; a series of black streaks low down along the sides. It feeds on _Lotus corniculatus_, and on other trefoils and clover: July to May. Sometimes taking two years to complete its changes.