94 WHEAT 



remains in the pupa stage in the stubble after 

 harvest. "Trap crops" are sometimes sown for 

 both insects, such as patches of millet planted 

 early in the spring to attract the chinch bug, and 

 the early planting of wheat in the fall to act as 

 a decoy to attract the flies. When the bugs have 

 congregated or the flies have laid their eggs, these 

 crops may be plowed under, thus destroying the 

 insects. Migrating chinch bugs may be kept out 

 of the fields to some extent by plowing protecting 

 furrows about the fields, and making coal tar 

 barriers, etc. Under certain favorable climatic 

 conditions chinch bugs may be largely destroyed 

 by fungous diseases to which they are subject. 

 The Hessian fly appears early in the fall, and its 

 attacks may be avoided by late sowing. 



At the Kansas experiment station (Manhattan) 

 the average of several trials shows results favor- 

 ing seeding during the last week in September 

 or the first week in October. Even later seeding 

 is less affected by the fly, but the very late sown 

 wheat is likely to make a weak growth in the fall, 

 and is more liable to be winter killed than earlier 

 sown wheat. Perhaps one of the best means for 

 checking these insect pests and the plant diseases 

 which attack wheat, is to practice a regular system 

 of crop rotation. The Hessian fly can be starved 

 out almost completely by the abandonment for 

 one year of the crops in which it breeds wheat, 

 rye and barley; while if a system of rotation with 

 corn be adopted that would entirely dissociate 

 small grains for a single season very little damage 

 from chinch bugs would occur. 



