The curious woodlouse-shaped caterpillar is green, sometimes inclining to yellowish; the broad reddish band on the back broadens out before the middle, thus giving the idea of a rough cross, or, as sometimes described, a blunt spear head. It is found, by searching, in August and until October, on the foliage of beech and oak. Birch has also been mentioned as a food plant, and on the continent it is said to feed on poplar, lime, hazel, and hornbeam. Fig. 2 on Plate [149] is from a photo by Mr. H. Main.
Although the caterpillar constructs its gall-like cocoon on a leaf or in the fork of a twig in the autumn, it does not change to a chrysalis until late in spring, sometimes not until June. The moth is out in June and July and flies in the sunshine, chiefly in the afternoon, and might easily be confused with the Lechean Tortrix (Ptycholoma lecheana).
| 2 Pl. 150. |
| 1, 2. Goat Moth. |
| 2 Pl. 151. |
| Goat Moth: caterpillar, chrysalis and cocoon. |
The species appears to be very local in England and confined to the south. Its chief haunts seem to be in Bucks, where it is not uncommon in beech woods at Marlow, and in Hampshire, especially parts of the New Forest. It has been found in Epping Forest, Essex; rarely in Abbot's Wood and Rewell Wood, Sussex; also recorded from Bickleigh Vale and the Plym Valley, Devonshire.
The range abroad extends to Amurland.