DISEASES OF WHEAT CAUSED BY INSECTS. 119 



Fig 15. 



two wings are hard and horny, and are used 

 to protect the flying wings. The order in- 

 cludes a great number of tribes, some of which 

 as the snout beetles are so numerous that 

 no fewer than 80,000 different kinds belong 

 to it. They are all eminently destructive of 

 farm and garden produce, to wit, the corn 

 weevil, (calandra granaria). To the order 

 Diptera which name indicates the chief 

 characteristic of the insects belonging to 

 it "two winged" belongs several insects, 

 the attacks of which form the principal 

 plague of the wheat crop namely, the "wheat 

 midge " (cecidomyia tritici), and the " hessian 

 fly" (cecidomyia destructor). The character- 

 istics of this order of insects are wings one illustrated 

 in fig. 1 6 two in number, which lie horizontally. The 

 head is hemispherical, the antennas very long, generally as 

 long as the body, the legs long. To the order Lepidop- 

 tera (scale winged) belong the vast number of moths, but- 

 terflies, the larvae of which are nearly all eminently de- 



Fig. 16. 



Fig. 17. 



