Fig. 233.—Larvæ of the Procession Moth (Bombyx processionea).
Fig. 234.—The Vapourer Moth (Orgyia antiqua), male and female.
The Orgyias comprise a great number of small species, of a dark colour, which do a great deal of damage to our forest trees. In Sep tember and October the male of the Orgyia antiqua, with his tawny wings, may often be seen flying about the streets of London. The female ([Fig. 234]) is remarkable, as she has only the rudiments of wings, and only goes as far as the side of her cocoon. The caterpillar of the Orgyia pudibunda, called also the Hop Dog, attacks almost every sort of tree. When the state of the atmosphere favours their propagation, they appear in fearful quantities, and cause the greatest havoc. During the autumn of 1828, in the environs of Phalsbourg, they were to be counted by millions. The extent of the woods laid waste was calculated at about fifteen hundred hectares. It is common in this country.
Fig. 235.—Orgyia pudibunda.
Among the genus Liparis, the species of which are also very destructive to trees, we must mention the Brown-tailed Moth (Liparis chrysorrhœa, [Fig. 236]), a species by no means rare in England. The caterpillars live in quantities, on apple, pear, and elm trees, and destroy the plantations of the promenades of Paris.