THE WHEAT CROP. 77 



Another midge (Cecidomya destructor}, called the 

 Hessian Fly, has been, and still is, from time to time, 

 such a fearful scourge to the wheat fields of North America, 

 that in some of the States the cultivation of wheat was 

 abandoned throughout extensive districts for many years. 

 Happily this member of the family has but very rarely 

 been met with in this country. Its powers of increase, 

 however, are materially kept in check by certain parasites, 

 especially the Geraphron destructor, which relieves the 

 farmer from myriads of his most dreaded enemies. 



The "Thrips" (Thrips cerealium) is the little black, 

 slender lizard-tailed insect which so frequently alights on the 

 face in hot weather, causing an irritation and annoyance 

 which prevents those who have once made its acquaint- 

 ance from readily forgetting it. This little fellow is 

 charged, also, with doing a great deal of injury to our 

 corn crops, especially wheat and rye. It appears to take 

 up its residence in the spathes and husks of the ear in 

 June, causing the grain to shrivel up; or, at an earlier 

 period, effecting the a,bortion of the ear altogether, by 

 puncturing the stems above the joints. They are so 

 numerous in our corn-fields that Kirby 1 says : " Of all 

 the insects that are found in wheat, this is, in all its states, 

 by far the most numerous. I don't recollect ever exam- 

 ining a single ear in which it was not found, and my 

 opinion remains unaltered, that it derives its nourishment 

 from the grain/' Linnaeus also noticed it, and accused it 

 of emptying the ears of corn. It appears to exhaust the 

 juices of the wheat, and to cause that shrivelled appear- 

 ance in the grain so often met with in certain seasons 

 arid in certain districts. The crops on strong soils are 

 said to be more subject to it than those on lighter soils, 

 and the late sown than the early ; the remedy, therefore, 

 is to sow as early as possible. Here, again, a check is 



1 Linnean Transactions, vol. iv. 



