Square Spot (Tephrosia consonaria).
Two examples of this species will be found on Plate [137], Figs. 3 ♂, 4 ♀. There is variation in the greyish or brownish speckling of the wings, and this in some typical examples is so sparse that the wings appear to be almost white with brownish basal band and brownish markings on the outer area; the most conspicuous of the latter being the middle square spot between the second and submarginal lines, more or less distinct in all forms, to which the English name refers. In other specimens the wings are, especially the front pair, densely covered with the dark speckling. Some Surrey specimens, chiefly from the Leith Hill district, have an ochreous tinge; and quite recently a black form of the species has occurred in a wood near Maidstone, in West Kent. The last phase of aberration seems to be unknown in any other part of Britain, and also, I believe, elsewhere.
The egg (Plate [138], Fig. 2) is yellowish green when laid; later it becomes yellow, and orange red markings appear, chiefly at one end.
The somewhat wrinkled caterpillar is ochreous brown above, inclining to greyish between the rings; an ochreous line along the middle of the back is only clearly defined on the front rings; the under side is greenish ochreous, and sometimes this colour extends to the upper side also; the head, which is notched on the crown, is pale ochreous, more or less marked with brown. It feeds at night, in June and July, on birch, beech, oak, pine, etc.
The moth is out in May and June, earlier in some districts. In the daytime it may be seen on the trunks or boughs of trees, most frequently at too great a height to be easily secured; but still a few sit low enough for capture, especially on the trunks of fir trees. The species is a decidedly local one, and seems to be largely confined, in Britain, to the southern parts of England, Wales, and Ireland. It occurs in some of the woods of Kent, Surrey, Sussex, Hampshire, Dorsetshire, Devonshire, Cornwall, Gloucestershire, Oxfordshire, Buckinghamshire, Bedfordshire, Essex, and Suffolk. Edwards notes the species as rare at Malvern, Worcestershire. Forsythe, in "A List of the Macro-Lepidoptera of Lancaster and District" (Entom. 1905, p. 12), states that the moth may be found sitting on the fir-tree trunks at the end of May, at Witherslack and Quernmore; and a single specimen has been recorded from Upton, near Birkenhead, Cheshire. The occurrence of T. consonaria in the north of England seems open to question. The only county in Wales appears to be Glamorganshire, as mentioned by Barrett. Kane (Catalogue of the Lepidoptera of Ireland) noted the species from Derrycunihy, and Mucross, Killarney, where he has taken it in moderate abundance; he also gives Clonbullogue, in King's County.
The range abroad extends to Amurland and Japan.
Grey Birch (Tephrosia punctularia).
Three examples of this greyish species are shown on Plate [137]. The wings are usually whitish grey in the ground colour, and sprinkled or dusted with darker grey; there are three blackish, or black dotted, cross lines on the fore wings, often indistinct, but rarely entirely absent, and even then represented by black marks on the front margin. Sometimes the first and third lines may be well in evidence and the central one absent; occasionally the second line is placed quite close to the first; the sub-marginal line is whitish, inwardly shaded with dark greyish, especially at the middle and towards the front margin. The hind wings have two cross lines corresponding with the first and third on the fore wings. There is a good deal of variation in the amount of dark speckling, and this is occasionally so heavy that the insect becomes dark grey in colour; I have taken such specimens at Oxshott in Surrey. Dark aberrations are perhaps more frequent in the north of England, but the species is more local and less plentiful in that part of the country.