INSECTS INJURIOUS TO WHEAT. 113 



succulent portions of the growing stalk. Numerous larvae 

 thus sapping the life of the plant soon kill it outright or 

 cause the top and head to wither and die. The adults of 

 this brood emerge in July and lay eggs on volunteer wheat 

 and grasses, the maggots working in the same manner as 

 in the fall and coming to maturity so that another brood 

 of flies lay eggs for the fall brood on the newly planted 

 wheat. 



Owing to the fact that this insect breeds also in grasses 

 during late summer it is much more difficult to combat 

 than were it confined to wheat as its food-plant, as is the 

 Hessian Fly. 



Jieniediex. — '' If the grain is stacked or threshed and the 

 straw stacked or burned/' says Prof. AVebster, " it is clear 

 that the number escaping would be greatly reduced,'' for, 

 as the adults emerge soon after harvest, they would escape 

 to deposit their eggs were the straw left in the fields, but 

 ^Mt is not likely that those in the centre of the stacks 

 would be able to make their way out, and the threshing- 

 machine vv'ould destroy many more.. How much could be 

 accomplished by late sowing of grain is uncertain, as the 

 females are known to occur abundantly up to October. 

 If plots of grain were sowed immediately after harvest in 

 the vicinity of the stacks, many of the females could, no 

 doubt, be induced to deposit their eggs therein, and these 

 could be destroyed by plowing under." Burning of the 

 stubble will also aid in keeping this jiest under control. 



There are several undetermined species of flies belong- 

 ing to the genus Oscinis, and very closely resembling the 

 common house-fly in miniature, being about one-fourth as 

 larcre, whicli have nracticallv the same life-historv as tlie 

 Wheat 8tem-maggot and injure the wheat in tlie same 



