250 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



Usually about 70 per cent of the infested squares drop, and in 

 these 70 to 80 per cent of the immature stages are destroyed by 

 natural causes.* 



Control By far the most important measure in the control of 

 the boll weevil is the destruction of the plants in the fall as 



soon as the cotton can be picked. This 

 both detroys the weevils and pre- 

 vents their increase. The stalks 

 should be plowed out and burned as 

 soon as possible. It is well to plow 

 out all but a row here and there 

 upon which the weevils will concen- 

 trate, then as soon as the piles are 

 dry enough to burn, cut the remain- 

 ing rows and burn at once. In this 

 way the great bulk of the adult 

 weevils and all of the immature stages 

 in the squares and bolls are des- 



T-, 01tr 7 troved. The few escaping weevils will 



FIG. 215. Solenopsis geminata , " . * 



Fab., a native ant which is a be starved out before the weather 

 valuable enemy of the boll becomes cold enough for them to 

 weevil much enlarged. ... 



(After Hunter and Hinds, U. hibernate, or will be so weakened as 

 S. Dept. Agr.) to fa e j n hibernation. Thus it has 



been shown by Professor Wilmon Newell, in Louisiana, that 

 where the weevils were forced into hibernation on October 15th 

 only 3 per cent survived the winter, but that when the destruction 

 of the stalks was put off until after December 15th, 43 percent sur- 

 vived, with proportional numbers at intervening dates. Further- 

 more, the development of the late broods which furnish the majority 

 of the weevils which hibernate is effectively prevented. The re- 

 moval of the plants also facilitates winter plowing, which aids in pro- 

 ducing an early crop the next year. Many experiments and the 

 experience of practical planters have shown that the destruction of 

 the stalks in the fall is of primary importance in the control of the 

 weevil, particularly upon bottom lands. Experiments made in 

 Calhoun County, Texas, where the stalks were destroyed on 410 



* See W..E. Hinds, Some Factors in the Natural Control of the Mexican 

 Cotton Boll Weevil, Bulletin 74, Bureau of Entomology, U. S. Dept. Agr. 



