1644. The only butterflies injurious to cultivated vegetables are, the large cabbage butterflies, Pieris brassica Lat. (fig. 286. c) &c., the small ditto (P. rapï¾µ, f), and the green-veined white (P. napi). The first is the largest; the caterpillar (a) is greenish yellow, irregularly marked with black spots, and, when full grown, is rather more than an inch and a half long: in this-state its ravages among cabbage beds are well known. The chrysalis (b) may be found, in summer and autumn, attached to posts, walls, outhouses, and the trunks of trees; this is, perhaps, the best time for destroying it, as the death of one may probably prevent the propagation of a whole brood: the perfect insect (c) might be placed in the list of ornamental butterflies, were it not so pernicious in its larva state. The small garden white, or cabbage butterfly, is frequently a still greater, pest than the last: the caterpillar (d) is of a delicate green, with small yellow rings on each side of its body; it conceals itself within the folded leaves in the centre of the cabbage and cauliflower, and is therefore less easily discovered: the chrysalis (e) is also green, and is found in similar situations to the last, towards the end of September. Broccoli is a favourite food of this insect. The green-veined white butterfly is likewise very troublesome in gardens: the caterpillar is green, but differs from the last in having three orange stripes; and the butterfly is known by the green nerves on the under side of the inferior wings: this has sometimes been called the turnip butterfly, from its infesting that plant, at certain seasons, in great numbers.
