FARM METHODS FOR THE CONTROL OF INSECTS 33 



of smartweed and other weeds and grasses until corn is available, 

 and cutworms feed on whatever vegetation is found before a 

 crop is planted. In this connection "volunteer" plants should 

 be classed as weeds, as they frequently furnish food for insects 

 in the same way. Thus the cotton boll weevil feeds on volunteer 

 cotton in early spring and the Hessian-fly on volunteer wheat 

 in late summer and early fall. Such useless trees as wild cherry 

 and seedling apple trees might also be considered as weeds, as they 

 harbor many of the insect pests of our orchards and should be 

 destroyed as far as possible. 



Fertilization and Culture. Although there is evidence that 

 under some conditions, kainit, lime and nitrate of soda may 

 have some direct effect on insects, it is probable that their chief 

 importance is so to stimulate the plant that it will not be subject 

 to insect attack or will grow in spite of some injury. It is well 

 known that plants which have been weakened from any cause 

 whatsoever are much more subject to the attacks of insects and 

 diseases, and it is therefore obvious that plants which have had a 

 vigorous growth and which will mature rapidly will much better 

 withstand insect attack. Thorough preparation of the soil 

 before planting, liberal fertilization, and thorough culture are 

 most important in growing a crop in spite of its insect enemies. 

 In many cases liberal fertilization and culture will mature a good 

 crop where under poorer care it would have succumbed to insect 

 injury. In general, land covered with barnyard manure presents 

 more favorable conditions for the hibernation of insects than that 

 fertilized with mineral fertilizers, but unless this is very appreciably 

 the case, the manure will usually be preferred when it is available. 



Clean Farming. After a crop has been harvested there is 

 usually some portion of the plant which is allowed to remain 

 on the land. In this refuse the insects peculiar to the crop often 

 feed and multiply until killing frost and then hibernate over 

 winter, ensuring injury to similar crops on the same land the 

 next year. The wheat joint worm and the corn stalk-borer 

 both winter in the stubble of those crops, and the chinch-bug 

 commonly hibernates in the butts of corn stalks. All of these 

 may be largely controlled by burning the stubble. Possibly 

 the most important means of control of the cotton boll weevil 

 is the destruction of the stalks in the fall as soon as the cotton 



