298 WHEAT FLIES THEIR INJURIES. 



themselves upon some of our wild grasses. Their numbers must 

 therefore have been very limited at that period". But when 

 wheat was introduced and became extensively cultivated, it 

 gave them such an ample supply of most palatable nourishment 

 that they have gradually increased and are now excessively 

 numerous all over our land, laying every wheat field under con- 

 tribution for their support. And I doubt not it is from the 

 numbers of these and other insect depredators which abound 

 upon our wheat, that we are no longer able to produce such 

 crops of this grain as were uniformly harvested formerly, when 

 our lands were newly cleared. How is it possible for wheat to 

 grow with any thriftness when it is incessantly assailed by such 

 hosts of these enemies, bleeding it at every pore? And if any 

 mode could be discovered by which our wheat could be pro- 

 tected from these depredators, I do not doubt that on our old 

 lands which have been under cultivation a century, we could 

 now, with our improved methods of tillage, rear crops of this 

 grain, surpassing those which grew upon the same lands when 

 they were newly cleared. And if wheat could thus be groAvn, 

 the intrinsic worth and the market value of lands in the old 

 settled sections of our state would be advanced probably one- 

 half. 



At the time of placing the specimens from which the accom- 

 panying illustrations were taken, in the hands of the draughts- 

 man, I supposed I should obtain some one or more of the larvae 

 of these insects, in its perfect state, and thus be able to present 

 its history with some approximation to completeness, in the pre- 

 sent report. But my efforts to rear them have been unsuccess- 

 ful. And it will scarcely be worth while to state the situation 

 in which one and another of these worms is found, and the 

 manner in which it mines or otherwise injures the straw, until 

 the particular species by which the mischief is done in each case, 

 can be identified and named. For the present, therefore, I 

 merely state what will serve to explain the accompanying figures, 

 and give the reader some acquaintance with this group of flies 

 as they appear upon the wheat in their perfect state. 



These flies form a particular tribe or sub-family, named the 

 Oscinides, the members of which may be distinguished from 



