THE CONTROL OF INJURIOUS INSECTS 375 



autumn most of the white grubs will be destroyed by the hogs. As 

 the grubs burrow deeply at the approach of cold weather it is not 

 advisable to pasture hogs late in the season. Clover is seldom 

 attacked by white grubs, hence is useful as a "starvation" crop 

 before planting to corn, potatoes or mangels. 



(c) Where the clover root borer is injurious in second year clover 

 fields, the sod should be plowed up after the first season. 



2. Good Cultivation. — This involves careful treatment of the soil, 

 the crop, and its products. It means careful attention to the waste 

 products and the waste places which are breeding places for many 

 injurious insects. It means the adoption of deep, late fall plowing 

 under certain conditions, which practice is one of the best methods 

 of dealing with wireworms, white grubs, cutworms and grasshoppers. 

 It means high fertility of soil, and good drainage of the land so that 

 vigorous healthy plants, capable of resisting the drains of insect attacks, 

 are grown instead of poorly nourished plants which are more likely to 

 succumb. 



Timely plowing, planting, and harvesting are often effective 

 against some of the worst insects of the farm. For example, two or 

 three fall plowings destroy large numbers of maturing wireworms 

 and white grubs; early plowing of grass in August destroys the eggs 

 and larvae of cutworms and grasshoppers. Late sowing of fall wheat 

 prevents Hessian-fly injury; and early cutting of the first crop of 

 clover destroys the first brood of the clover seed midge and thus 

 saves the clover seed of the later crop. 



The destruction of rubbish, screenings, stubble, dead stalks and 

 weeds deprives many hibernating insects of resting or breeding 

 places. Such insects are Hessian-fly "flaxseed," chinch bug, clover 

 hay worm, tarnished plant bug, squash bug, stalk borers, etc. 



Cutworms endeavor to lay their eggs in August and September on 

 weeds and grasses. Consequently if the land is kept free from weeds 

 and the grass is fed or mown few cutworms will appear the following 

 spring. 



The application of fertilizers, such as nitrate of potash, barnyard 

 manure, wood-ashes, and tobacco dust, is often advantageous in forcing 

 the growth of plants that are attacked, and in repelling insects. 



3. Co-operative Measures. — Co-operation among the farmers of a 

 district is required for the successful control of certain insects such 



