INJURIOUS INSECTS OF 1903. 7 



From the foregoing observations one would naturally con- 

 clude that probably the fly would be found in an immature stage 

 upon wheat which had volunteered in the stubble field, and such 

 proved to be the case, both "flax seed" and maggots (second 

 stage) being found on volunteer wheat growing in stubble in 

 Clay county October i8th. 



This last finding is significant, showing that winter wheat 



Fig. 5. — Four Hessian Fly larvae on one stalk, just changed to "flax seed" stage. 

 Enlarged four times. Original, 



would be affected if raised in Minnesota and also showing an ad- 

 ditional source of infection when the volunteer is not turned un- 

 der ; in other words, the "flax seeds" seen in the stubble might 

 not account for the injury to the crop in the early part of the fol- 

 lowing season, but these, plus those in the volunteer which we 

 have not hitherto considered, might easily be responsible for 

 the quite extensive injury caused by the first generation the fol- 



