186 INSECTS AFFECTING FIELD CROPS 



normal plants. Later, when the head is formed and about the time 

 the grain is in the milk, the weakened straw breaks just above the 

 working place of the maggot, causing the grain to lodge or 



FIG. 205. Puparia of Hessian' fly, so-called "flaxseeds, " in infested wheat stems. Also 

 showing characteristic breaking down of stem. (Original.) 



the heads to lie on the ground and be missed by the binder. Ker- 

 nels in affected plants are poorly filled and shrunken. 



Control. Plowing the stubble and rotation of crops are good 

 farm practices in connection with this insect. All volunteer 



