No. 105.] 265 



loss from the wheat-fly, upon the data above indicatedj may be set down 

 at three and a half millions of dollars! 



The history of the career of this insect, appears to be quite uniform 

 in most of the districts hitherto visited by it. About two or three years 

 after its first arrival at a particular locality, it becomes most excessively 

 multiplied, and the devastations which it now commits are almost 

 incredible. Though I believe that, through unduly excited fears, or 

 a hope of thereby destroying hosts of this marauder, a mowing of 

 the crop whilst yet green and a curing of it for hay has often been 

 resorted to, when, had it been harvested as usual, a less sacrifice would 

 have been made — yet many cases have occurred in which diligent 

 search by different persons has failed to discover a single developed 

 kernel of grain in any of the heads of an entire field I 



This havoc, so extreme and general, though not universal (for some 

 fields even now escape with comparatively little injury,) lasts but a 

 few years. The numbers of the pest and its consequent ravages soon 

 become sensibly diminished ; and after the lapse of some seasons, the 

 cultivation of the wheat crop is again found to be comparatively safe, 

 and its yield only in isolated instances materially lessened by the con- 

 tinued presence of the fly, which has now become probably a perma- 

 nent inhabitant. 



It is now commonly supposed that this rapid diminution in the num- 

 bers of the wheat fly has been produced by the general abandonment 

 of the cultivation of wheat in this section of the country ; that thus 

 the insect, having no place to deposit its eggs where its young could 

 be nourished, has become measurably '' starved out." But that this 

 opinion is erroneous, is I think evident from one or two facts. During 

 this entire period, since notice was first attracted to the wheat-fly, there 

 are some farmers who have every year continued the cultivation of 

 wheat with very fair success, their crops having been in no one of these 

 years so severely injured as to dishearten them ; and their respective 

 situations are so dissimilar, that this immunity can with no plausibility 

 be attributed to any peculiarity in the location of their farms. Now if 

 the swarms of these insects which for a time pervaded every neighbor- 

 hood through this entire section of country,, and which possess a power 

 of wing capable of bearing them from twenty to fifty miles in a single 

 season, had been in the "starving" condition supposed, how have the 

 fields alluded to escaped destruction? Certainly these myriads of tiny 



