265 
No. 105.] 
loss from the wheat-fly, upon the data above indicated, 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! 
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. Turing 
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 
