This moth differs from the last in its generally smaller size, but more especially in the shape of the black line forming the outer margin of the central band; this is always more or less angled or dentate towards the front margin of the wings, whereas, in the Poplar Kitten, this portion of the line forms a clean curve (Plate [22], Figs. 4, 5).
The eggs are black, rather glossy, and are generally deposited in pairs, but rarely more than three, and often only singly, on the upper surface of a leaf of sallow or willow. The caterpillar feeds from July to September, sometimes as early as the end of June, or as late as October. It is green, with a yellow tinge; the markings on the back are similar to these characters in the caterpillar of the preceding species, but, as will be seen by looking at the figures on Plate [23], they are not quite the same in outline. The figure of the young caterpillar on this plate was made soon after it left the egg, and the shell from which it emerged is also depicted. Sallow and willow are the usual food plants, but in August, 1906, I found a half-grown caterpillar of this species on aspen, but it died a few days afterwards. The reddish-brown chrysalis is enclosed in the usual hard cocoon of its kind, which is affixed to a branch or the trunk of the tree upon which the caterpillar fed. A depression is usually selected, and when the cocoon is finished off with its covering of bark fragments it is difficult to see.
The species is well distributed over England, Ireland, and Scotland; perhaps more frequently obtained on the mosses of Cheshire, Lancashire, and Yorkshire, than in other parts of England. It is found in Central and Northern Europe, and, according to Staudinger, in Amurland and North America.
The Puss Moth (Dicranura vinula).
Portraits of both sexes of this rather common moth are given on Plate [24]. The head, thorax, and body are very fluffy. The whitish fore wings are crossed by several wave-like lines; the main veins (nervures) are ochreous, and the branches (nervules) are blackish; beyond the more or less clear basal area there is often a broad but irregular blackish band, and the wavy markings on the outer area vary in intensity (sometimes the short streaks between the veins terminate on the outer margin in black dots). Hind wings whitish in the male, and suffused with blackish in the female, to a greater or lesser extent. In some examples of the female the fore wings and the body are also tinged with blackish. The antennæ are bipectinated in both sexes, but those of the female have the teeth much shorter than those of the male.
The eggs are usually laid in pairs on the upper surface of a leaf of sallow, willow, or poplar. In colour these are purplish or reddish brown, shining, and finely grained; a minute depression at the top is yellowish, with a black speck at the bottom of the hollow.
In its last stage the caterpillar is green, with a white or yellowish-edged purplish brown band on the back; the head is light brown margined with black and purplish behind, and the ring immediately following (first thoracic) is green margined with yellow and having two black spots on the upper part. When the creature assumes the position which Professor Poulton terms the terrifying attitude, the front part is elevated, the head is drawn back into the ring next to it, and the tails are raised and curved forward over the back (see Plate [25]). Seen thus from the front the appearance of the caterpillar is certainly grotesque, and no doubt affords it some protection from its enemies. It feeds on poplars, sallows, and willows, usually in July and August, but sometimes as late as September.
