JOMAL OF AGRldllAl RESEARCH 



Vol. XVIII Washington, D. C, February 2, 1920 No. 9 



EUROPEAN FRIT FLY IN NORTH AMERICA 



By J. M. Aldrich 



Entomological Assistant, Cereal and Forage Insect Investigations, Bureau of Entomology, 

 United States Department of Agriculture 



INTRODUCTION 



The investigations reported in the following pages were made at La 

 Fayette, Ind., except as otherwise indicated, in the years 1914-1916. 

 They relate to the European frit fly, an insect which attacks both winter 

 and spring wheat every year over the whole geographical range of the 

 crop and at times has done considerable damage. This fly has received 

 little study in this country on account of its minute size, the difficulty 

 of carrying it through its life cycle in cages, and the confused and uncer- 

 tain condition of its classification, which made it impossible to tell how 

 many species were involved. The similarity of its attack to that of the 

 Hessian fly has also, no doubt, in many cases prevented its recognition 

 as a grain pest. 



HISTORY AND SYNONYMY 



In 1750 a paper was presented by Linnaeus (13),^ the celebrated natural- 

 ist, to the Swedish Academy of Sciences, in which he described the injury 

 caused to barley in Sweden by the larvae of a small black fly which he 

 found was destroying the immature kernels of the grain to a serious 

 extent, in many heads eating out almost every kernel. Such light 

 and worthless kernels the Swedes called "frits." The species was 

 not given a scientific name until 1758, when the same writer (14, p. ^gS) 

 described it as Musca frit. Fabricius (7, p. 216) in 1805 included the 

 species under Oscinis, and it has generally been known as Oscinis frit 

 since that date. 



A century after the species had been described, it was found that the 

 larvae of the late fall brood winter as stem miners in winter grain, chiefly 

 rye, in Europe, and that spring grain, especially rye and oats, is attacked 

 in the same way by the spring brood. The summer brood was found 

 to attack the kernels of oats more commonly than those of barley. These 

 differences were for a long time supposed to indicate that several, at 



1 Reference is made by number (italic) to " Literature cited," pp. 472-473. 



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