ARMY-WORM. Leucania (Heliophila) uni Of this insect, Dr. Riley, in his Ninth Entomological Report, says it is with is every year. In ordinary seasons, when it is lot excessively numerous, it is seldom noticed: 1, because the moths are low, swift fliers, and nocturnal in habit; 2, because the worms, when young, have protective coloring, and, when mature, hide during the day at the base of meadows. In years of great abundance the worms are generally unnoticed during early life, and attract attention only when, from crowding too much on each other, or from having exhaust ed the food supply in the fields in which they hatched, they are forced, from necessity, to mi grate to fresh pastures in great bodies. The earliest attain full growth and commence to travel in armies, to devastate our fields, and to attract attention, about the time that winter wheat is in the milk—this period being two months later in Maine than in Southern Missouri; andthey soon afterwards descend into the ground, and thus suddenly disappear, to issue again two or three weeks later as moths. In the latitude of St. Louis the bulk of these moths lay eggs, from which are produced a second generation of worms, which become moths again late in July or early in August. Ex ceptionally a third genera tion of worms may be pro duced from these. Further
north there is but one gen eration annually. The moths hibernate, and ovi posit soon after vegetation starts in spring. The chrysalides may also hiber nate, and probably do so to a large extent in the more northern States. The eggs are inserted between the sheath and stalk, or secret ed in the folds of a blade; and mature and perennial grasses are preferred for this purpose. The worms abound in wet springs preceded by one or more very dry years. , They are preyed upon by numerous enemies, which so effectually, check their increase, whenever they unusually abound, that the second brood, when it occurs, is seldom noticed; and two great army-worm years have never followed each other, and are not likely to do so.. They may be prevented from invading a field by judicious ditching; and the burning over of a field, in winter or early spring, effectually prevents their hatching in such field. It has numerous natural enemies, among which may be noticed, some parasites, the Red-Tailed Tachina Fly, the Yellovi-Tailed Tachina Fly, also Icli neumon flies. Various predaceous beetles and their larva also prey upon it.