480 THE SMALL GRAINS 



oil or tar, will run along the line and tumble into the holes, 

 where they may be destroyed with kerosene. 



Two species of fungi (Entomopthora aphidis, Hoffman, 

 and Sporotrichum globuliferum, Speg.) are found parasitic 

 on the chinch bug. It has been attempted to annihilate 

 the insect by artificially propagating these fungi in quan- 

 tity, and spreading them among the bugs in the field. 

 The very conditions of continued wet weather favorable 

 to the fungi, however, are very unfavorable to the chinch 

 bug, so in such weather the former are scarcely needed, 

 while in dry weather when the bugs are most active the 

 fungi do not multiply. 



526. The wheat midge (Diplosis tritici, Kby.) is a close 

 relative of the Hessian fly, but unlike the latter works in 

 the spikes of wheat, feeding on the soft developing ker- 

 nels, causing imperfect filling, shriveled kernels, and 

 blighted spikes. There are occasionally unusual out- 

 breaks of this insect during which it causes great damage, 

 but ordinarily it is much less serious than the chinch bug 

 or Hessian fly. 



The very minute oval eggs, pale red in color, are deposited 

 singly or in clusters to the number of 10, in the crevices of the 

 wheat spikes. These hatch in about a week and the orange-yellow 

 larvae or maggots find their way at once to the kernels. The full- 

 grown larva is oval, about -fe inch long when quiescent, somewhat 

 longer in motion, and lives about three weeks. Many larvae are 

 still in the spikes when the grain is harvested, and are carried to the 

 stack and to the thrasher, and are then often called "red weevils." 

 The others pass from the wheat spikes to the ground, where they 

 prepare cells in which to pass the winter. 



Crop rotation and deep fall plowing of infested fields 

 will readily control this pest. The deep plowing buries the 

 larvae so deeply that they cannot escape the following year. 



