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AGRICULTURE FOR BEGINNERS 



pupa state without changing its home. Then in about a 

 week more the pupae come out as adult weevils and attack 

 the bolls. They puncture them with their snouts and lay 

 their eggs in the bolls. The young grubs, this time hatch- 

 ing out in the boll, remain there until grown, when they 

 emerge through holes that they make. These holes allow 



dampness to enter and 

 destroy the bolls. This 

 life round continues until 

 cold weather drives the 

 insect to winter quarters. 

 By that time they have 

 increased so rapidly that 

 there is often one for 

 every boll in the field. 



This weevil is proving 

 very hard to destroy. 

 Many plant pests when 

 they are grown or when 

 they are in the larva state 

 can be killed by the appli- 

 cation of poisons. But as 

 the grown weevil is a 

 tough, hard-shelled insect, 

 neither internal nor exter- 

 Moreover, as the larvae live 

 in the cotton boll, poison cannot reach them ; hence it 

 seems that no poison can be relied upon to exterminate 

 this pest. Machines for knocking the weevil from the 

 boll and for collecting and destroying weevil-filled bolls 

 have been tried, but so far have either failed or proved 



FIG. 262. A COTTON BOLL WITH 

 FEEDING HOLES OF WEEVIL, 



AND BEARING THREE SPECI- 

 MENS OF THE INSECT 



After an original furnished by United 

 States Department of Agriculture 



nal poisons seem to affect it. 



