The mature larva (Plate [49], Fig. 2) has the head and markings thereon like neustria, also the black spots on the first thoracic segment, but they are rather large and inclined to unite. The bluish line along the sides is dotted and freckled with black rather more thickly than in castrensis; the dorsal line is very thin, but bluish as in castrensis, and the red lines on each side of it are broad.
In colour the three moths are deeper brown than any form of either parent species that I have seen, but the transverse lines, and especially the outer, are most like those of neustria.
It should be mentioned that much information on Hybridism in the Lackey moths and other species will be found in Tutt's "British Lepidoptera," vol. ii.
The Pale Oak Eggar (Trichiura cratægi).
In its typical form the male of this species (Plate [50], Figs. 1, 2) is ashy grey, with a darker central band on the fore wings; and the female is dusky greyish-brown, also with a darker band. The colour of the male varies in shade from almost whitish (var. pallida, Tutt), to blackish grey; in the paler forms the central band of the fore wings is often of a purplish tint, and in the darkest forms the band is almost black. The female var. pallida, is pale buff.
The eggs, which are brownish, inclining to reddish on the micropylar area, are covered with dark grey hairs from the body of the female and laid side by side in a chain-like arrangement on a twig of hawthorn or sloe (those figured on Plate [51] were deposited in a box, and not securely attached). From eight to twelve is said to be the usual number in a batch, and each female will deposit an average of 160 eggs.
The caterpillars do not hatch out all at the same time, but by ones and twos, at intervals spreading over a period of two, or perhaps three, weeks. Several forms of the caterpillar have been described, but the ground colour is generally more or less black above and greyish on the sides; the ornamentation comprises interrupted white or whitish stripes, streaked or clouded with reddish, and reddish warts; the hairs are reddish brown. The example figured on Plate [51] was from eggs laid by a female moth in Selkirk, South Scotland. From the age of three weeks until it became full grown it was black marked with yellow on the back and orange on the sides; hairs pale greyish mixed with black ones, especially on the back towards the black, glossy, and somewhat hairy head. It hatched on April 26, was reared on plum, pupated early in June, and the moth, a darkish grey female, emerged on July 31. Another caterpillar that hatched on May 1, and two others from still later hatchings, were then in chrysalis.
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