140 DISEASES AND INSECT ENEMIES 



Whenever the fly is noted as present at harvest time, late planting 

 should be practised that fall. 



Chinch Bugs. Chinch bugs are favored by dry climate, and are 

 seldom injurious east of the Mississippi Eiver. Two or three dry 

 seasons in succession will favor their rapid increase. Chinch bugs 

 harbor in stubble, grass clumps or in weedy fence-rows during the 

 winter. If grass is kept down by clean culture, stubble plowed 

 under, and fence-rows fired late in the fall, the bugs can, in a meas- 

 ure, be controlled. 



The Plant Louse. The louse generally is found on the wheat 

 in the fall. If conditions are favorable the following spring it may 

 increase at an enormous rate. It is rarely injurious and no control 

 measures have been proposed. 



The Wheat Midge. This is a small two-winged fly that lays 

 its eggs on the glumes of the wheat head at about blossoming time. 

 The larva sucks the juice from the young wheat grains, causing them 

 to shrivel up. The pupa passes the winter in the 'soil near the base 

 of the wheat plant. No control measures are proposed except deep 

 fall plowing. 



QUESTIONS 



1. Describe rust in appearance and method of spreading. 



2. Distinguish between the two kinds of smut as to difference in ap 



pearance. 



3. In mode of infection; in treatment. 



4. Why are insect enemies so irregular in attacks? 



5. Give life history of the Hessian fly. Method of control. 



6. Give control of chinch bugs. 



7. Describe work of the wheat midge. 



