DIPTERA OF MINNESOTA. 



(51 



no further comment at this time ; yet on account of its widespread 

 distribution in Minnesota, and the importance of knowing the best 

 way to handle it, we give here, in condensed form, the methods of its 

 control : 



I. Burn the stubble when, from any reason, shallow plowing is 

 unavoidable, or when plowing is to be delayed in the spring until 

 after emergence of flies. If the stubble is left long it will burn easier. 

 Some farmers are willing to go to the trouble of spreading straw from 

 threshing over the stubble, thus insuring the burning, and at the same 



Fig. 48. Different stages of Hessian Fly; (a) female; (b) flaxseed pupa; (c) larva; (d) 

 head and breast bone of same; (e) puparium; (f) cocoon; (g) infested wheat stem 

 showing emergence of (pupae and adults. From C. L. Marlatt, U. S. Dept. of 

 Agriculture, Bureau of Entomology. 



time the getting rid of some "flax seeds" which may have lodged on 

 the surface of the straw pile at the time of threshing. It is well, how- 

 ever, to remember that repeated burnings, from the standpoint of our 

 chemists, are not good for the soil. 



2. Fall plowing of the stubble in such a way that the straw is 

 completely turned under. In this connection we should not overlook 

 the fact, made evident from the findings of 1903, that volunteer wheat, 

 wherever found in the fall, may contain "flax seeds." 



