Scotch or Mountain Burnet (Zygæna 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 Aberdeenshire, 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 procumbens, etc.; has been known to eat dock and knot-grass: August to June. The cocoon has been found on a stem of crowberry (Empetrum), and on heath and grass stems. The moth is out in July, and, like the rest of its kindred, delights in the sunshine.
Zygæna achilleæ.
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, Argyllshire. Mr. Sheldon informs me that he believes that a worn Zygænid 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
respects this species is not unlike some confluent-spot forms of filipendulæ, 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. viciæ, Hübner. In the typical forms the spots are larger. A yellow form ab. flava, Oberthür, 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 (Zygæna meliloti).
Two examples of this, normally, five-spotted little species are shown on Plate [146], Figs. 4 ♂, 5 ♀; 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. sexpunctata, 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.