466 Journal of Agricultural Research voi. xviii, no. 9 



symptom of infestation (the dying of the central shoot) does not appear 

 so quickly. In the spring of 19 17 the point was further tested by trans- 

 planting wheat from fields to pots under cages, to compare it with rye 

 and several grasses treated in the same way. Glass cylinders were placed 

 over several grasses outdoors without transplanting, and several lots of 

 wheat and grass were taken into the laboratory and all the stems slit up 

 to find larvae. The net result was that the fly was found to winter in 

 timothy and meadow fescue, but not in wheat, rye, or several other 

 grasses. The explanation which best harmonizes this result with other 

 observed facts is that the insect has a rather wide range of habits and may 

 concentrate upon any one of several food plants, just as it sometimes 

 severely attacks the young, unripe grains while ordinarily it does not 

 ■ affect them. 



INFESTATION OF RYE 



A small percentage of infestation was obtained in rye sown in the 

 garden rather late in spring. The European literature contains frequent 

 references to Oscinis frit as a pest of rye, but the crop is so little raised 

 in the United States that the insect heretofore has escaped notice in 

 this connection. 



INFESTATION OF BARLEY 



Limiaeus {13) in his classic first paper on Musca frit described the infes- 

 tation of barley kernels on an extensive scale, beyond anything that has 

 been seen since. He estimated that one-fifth of the barley crop was 

 aimually destroyed by the insect. A few years later in another paper 

 he reduced the estimate to one- tenth, indicating that further observation 

 had not shown so great infestation as in the first instance. The insect 

 also attacks barley stems in the spring, as indicated in European litera- 

 ture and confirmed by the writer. 



INFESTATION OF OATS 



The oat fly is a term used in England for Oscinis frit. Wilhelm {24) 

 published a 40-page pamphlet in Germany on it, using the same name 

 (die Haf erfliege) . In both countries it has often been noted mining the 

 young shoots and destroying the ripening kernels. Westwood {22, 23) 

 reports a striking instance of infestation of oat kernels in England, 

 attributing it to O. atricilla Zett. A farmer had thrashed 25 quarters of 

 oats and stored them in a loft. The following account was written to 

 Westwood by J. B. Yonge, Esq. 



A few days afterwards a stratum of flies was seen on top of the Oats, coming up 

 among them, and passing away through the window. The stratum was about 4 feet 

 long, I broad, and 3 inches thick, and being continually renewed from below as those 

 above passed off, an immense number must have gone through during the four days it 

 v/as obsen/ed. 



