GENERAL FARM METHODS AGAINST INSECT PESTS. 23 



removed from the field as soon after it is harvested as 

 possible Such material allowed to remain in the field 

 also furnishes the adult insects an excellent place in which 

 to hibernate over winter. Much can be done to rid a field 

 of insects by cleaning it so thoroughly as to deprive them 

 of shelter during the winter, during which time they 

 hibernate under all sorts of rubbish, grass, and weeds, in 

 fence-rails, loose bark of trees, etc. This fact may also 

 often be utilized by first carefully cleaning a field and then 

 leaving one or two piles of rubbish in which various insects 

 will assemble during the winter, when they can be easily 

 caught by burning the whole. Such a trap will be more 

 effectual in catching the insects affecting truck crops than 

 those of the staple crops. 



Weeds. 



But even when all the piles of litter and rubbish have 

 been carefully cleared up many of our native insects will 

 merely leave them for some common weed upon Avhich 

 they will feed and breed during the season^ and, if it should 

 be earlier than the cultivated crop, will continue upon it 

 the following spring until the cultivated crop is to be 

 secured for food. '• Volunteer *' plants should be included 

 with weeds in this connection, as they frequently serve the 

 same purpose. Thus the Cotton Boll-weevil feeds upon 

 volunteer cotton during the spring, and the Hessian Fly 

 on the volunteer wheat during late summer, while the 

 Corn Root-louse lives on the roots of the smart-weed 

 until corn is out of the ground. Then, too, many in- 

 jurious insects feed in the larval or adult stage upon some 

 common weed, while in the other stage they are injurious 

 to a cultivated crop. The flea-beetles thus feed upon the 



