1660. The different crane-flies (Tipulidï¾µ) comprise several insects, more or less destructive, in their larva state, to the labours of the agriculturist, though not very prejudicial to the gardener. The largest of these is the Pedicia rivosa (fig. 292. c), known to country people by the whimsical name of gaffer long-legs. Two other species, in their larva state, are confounded with this under the common appellation of the grub. The first belongs to Tipula oleracea; it is sometimes very prejudicial to grass in low marshy grounds, and sometimes even to grain. In France, it has been known to destroy the grass in whole districts; and in England, it sometimes cuts off a large proportion of those wheat crops that have been raised upon clover-lays. The other is the larva of Tipula cornicina, which, in the year 1813, destroyed hundreds of acres of pasture in Holderness. Tipula crocata (a) lives in the same manner, but is much less hurtful. But no dipterous insect is more injurious to corn than a small crane-fly of an orange colour, named by Mr. Kirby, Cecidomyia tritici (fig. 292. b). The female, which is best seen when magnified (h), introduces its long retractile ovipositor into the centre of the wheat-flower, and has been known to deposit twelve of her eggs (d) in a single ear of the plant. These, being hatched, produce a very small larva (f), which, when magnified (g), resembles a large maggot: it feeds upon the pollen, prevents the impregnation of the grain, and thus frequently destroys a twentieth part of the crop. (Linn. Trans.) Rye, in the same manner, is attacked by another fly, though of a different genus (Chlorops pumilionis) (fig. 293. f): it inserts its eggs into the heart of the plant, and the larva occasions so many to perish, that from eight to fourteen are lost in a square of two feet: this, and Cecidomyia tritici, have been mistaken by many writers for that terrible insect, the Hessian fly, which, fortunately for this country, still remains confined to America.
