HESSIAN FLY, a name originally given in the United States in 1776 during the War of Independence to a small fly very destructive to wheat, supposed to have been brought over in straw by the Hessian troops employed on the British side. It is a species of Cecidomyia, described under the name C. destructor by the American entomologist Say, and belonging to the Dipterous family Cecidomyiida>, the numerous members of which produce galls, distortions, and other injuries in the plants they attack. It was often thought that this insect occurred in England; but the indigenous English wheat-midge, also very destructive, is an allied species, Diplosis tritici. A species found in Hungary and Germany, where it has committed great damage, has been supposed to be the true Hessian fly, which has also been recorded from Minorca and Naples; Cohn notices its ravages in Silesia, and Künstler in Austria; and Kaltenbach (who identifies C. secalina, Loew, with it) says it is more or less common in Germany, and that it originally came from Europe. Nevertheless, many good authorities have considered that the destructive European fly is not identical with the North American insect, though closely allied to it, and of similar habits. In the United States this minute midge has been a dreadful scourge at times, even to the extent of causing local famine. The female lays 20 or 30 eggs in a crease of the leaf of the young plant, and the larvae when hatched work their way between the leaf and the stalk, till they come to a joint, a little below the surface, where they remain, head down, sucking the sap, and turn to pupae enclosed in a covering; this is known as the “flax-seed” condition. The injury occasioned is not detected until the plant grows higher. There are two broods every year, one ...