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Linnaeus described the insect in 1758 as Muscnfrit ; Fabricius included 

 it in the genus Oscinis. Since that date frit flies have been recorded 

 as various species of Oscinis in North America, but the author's 

 studies of these forms have led liim to the conclusion that 0. pusilla, 

 Meig., 0. nitidissima, Meig., 0. carbonaria, Lw., 0. variabilis, Lw., 

 0. nigra, Tucker, and 0. soror, Macq., are all synonyms of Oscinella 

 {Oscinis) frit, the multiplicity of names having arisen from the varia- 

 bility and wide distribution of the species. 



This fly is most abundant in the region where winter wheat is gr( wn, 

 i.e., from the Great Lakes to the Ohio River and westward to the 

 Missouri. Outside this area it has been found in abundance locally 

 from the Atlantic to the Pacific and from Ottawa to the Gulf of 

 Mexico, its northern Hmit being 58° in Alaska. It is general wherever 

 grass is abundant and green for a considerable part of the year. In 

 the arid West it occurs along streams, in irrigated pastures, or at 

 high altitudes where the humidity is greater. The various stages of 

 the insect are described. 



In Indiana, where these investigations were made, 0. frit winters 

 in the larval stage in winter wheat. Following the emergence of 

 this brood in spring, there are four summer generations. The method 

 of rearing these generations in the laboratory is described. The first 

 emergence extended in 1916 from about the middle of April to mid- 

 May ; adults of the first summer generation emerged from about 

 12th June to 13th July, those of the second generation from 16th to 

 26th July, those of the third, from 10th to 28th August. Only two 

 flies of the fourth summer generation were reared ; these emerged on 

 24th and 25th September. While the record covers too few individuals 

 to exclude the possibihty of variation in the number of generations, 

 it indicates that four summer generations are the normal number. 



The flies oviposit on the young and tender shoots of grains and grasses, 

 the larvae entering the shoot and feeding downward in the middle ; 

 occasionally eggs are laid on or within the glumes just after heading' 

 in which case the larvae eat out the soft kernel. The flies seem to be 

 attracted by an exudation from the fresh epidermis of grass that 

 IS producing new shoots. Bluegrass lawns that are kept watered 

 and mown yield large numbers of 0. frit, practically throughout 

 the season. _ The relation of 0. frit to grasses requires much further 

 study. A list is given of the known food-plants of the species ; 

 tmiothy grass, which is included in the fist, has proved unattractive! 

 In experiments, wheat, rye, emmer, barley and oats were infested 

 m the prder given. While in England, 0. frit is frequently referred 

 to as " the oat fly," in America it seems not to feed upon the oat 

 at all, unless compelled to do so, when it sometimes accepts oats 

 and sometimes prefers starvation. Wheat, on the other hand, is 

 preferred for oviposition ; eggs are laid on the autumn wheat soon 

 after it_ appears, and spring wheat is attacked by the first summer 

 generation. A characteristic symptom of infestation in voung shoots 

 of all kinds is the dying of the central leaf, while the others around 

 It remain green. While in cool and moist weather the injured leaf 

 may remain green for some time, in hot dry weather it is killed at 

 once. The insect Tias rather a wide range of "" habits and mav concen- 

 trate on any one of several food-plants ; it sometimes severely attacks 

 young, imripe grains, though ordinarily it does not affect them. 



