Cossus
a genus of nocturnal lepidoptera, family hepialidæ or ghost-moths. They have long, slender, half-serrate antennæ, a small head, and the upper wings longer than the lower ones. The larvæ feed on wood, the pupa is inclosed in a cocoon. C. ligniperda is the goatmoth, so called because its larvæ emit disagreeable smell, as the goat does. It is a large moth, the upper wings gray mottled with white, and having moreover black bands; the lower ones brownish ash; the body brownish gray, with silvery lines. The ground color of the larva is yellow. It takes three years to come to maturity.