INSECTS INJURIOUS TO COTTON 



269 



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 destroys the weevils 

 and prevents 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 concentrate, then as- 

 soon as the piles are dry enough 

 to burn, cut the remaining rows 

 and burn at once. In this way the 

 great bulk of the adult weevils 

 and all of the immature stages 

 the squares and bolls are 



FIG. 199. Solenopsis geminata 

 Fab., a native ant which is a 

 valuable enemy of the boll 

 weevil much enlarged. (After 

 Hunter and Hinds, U. S. Dept. 

 Agr.) 



Thus it has been shown by 



in 



destroyed. The few escaping wee- 

 vils will be starved out before the 

 weather becomes cold enough for 

 them to hibernate, or will be so 

 weakened as to die in hibernation. 

 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 p'ut off until after December 15th, 43 per cent survived, with 

 proportional numbers at intervening dates. Furthermore, the 

 development of the late broods which furnish the majority of the 

 weevils which hibernate is effectually prevented. The removal 

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

 ing 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 

 acres, showed an increase the next season of over one-quarter 

 bale per acre as compared with fields where the stalks had been 



