124 FARM FRIENDS AND FARM FOES 



the winter. In the spring, still inside, they change to pu- 

 pae, and a little later change again to adult Hessian Flies. 

 These adults lay eggs for another generation of larvae that 

 attack the wheat in the spring and cause much of it to be 

 so dwarfed and weakened that the crop is seriously injured. 

 As a rule, this brood of flies seems not to become mature 

 until the latter part of the season. 



In the case of an insect so minute and so protected 

 during its earlier stages as the Hessian Fly, many insecti- 

 cidal methods of controlling it are useless. Consequently, 

 farmers must resort to agricultural methods if they would 

 prevent damage by it. One of the most successful of 

 these methods is that of planting narrow strips of wheat 

 early in the fall, to attract the flies to lay their eggs, in 

 order that the main crop of wheat planted later may escape 

 infestation. The early trap crop may then be plowed un- 

 der, so that the eggs and larvae present will be destroyed. 



Another insect belonging to this same family and also 

 attacking the wheat is called the Wheat Midge. The 

 larvae in this case are found in the heads of grain rather 

 than in the stalks, and the damage they do is in the de- 

 struction or dwarfing of the kernels of wheat. In recent 

 years this insect seems to have done comparatively little 

 damage. 



Closely related, both in structure and habits, to the 

 Wheat Midge is a tiny fly called the Clover-seed Midge. 

 The flies lay their eggs in the blossom heads of clover, 

 and the eggs hatch into larvae that develop at the expense 

 of the young seeds, often causing a serious lessening of 

 the crop where clover is grown for seed. The injury to 

 hay crops, however, is very slight. 



The Pear Midge is the most destructive insect of this 

 family that attacks fruit. The eggs are laid in the flower 



