18 NATURAL CONTROL OF THE COTTON BOLL AVEEVIL. 



t^iving rise in the sprin<^ to what is variously torined sprout, stuhble, 

 or soppa cotton. These sprouts arising from roots which are already 

 established begin growing, as a rule, before cotton is planted. Their 

 growth is exceptionally vigorous, so that these plants fi^equontly 

 produce squares several weeks in advance of the average planted 

 crop. This source of food supply, occurring so early in the season, 

 serves to sustain a large number of hibernated weevils from the time 

 of their emergence imtil after the planted cotton becomes suscep- 

 tible to their attack. It also furnishes early emerged weevils with 

 opportunities for reproduction, which may produce a large number 

 of first generation weevils by the time planted cotton begins to form 

 squares. It has been noticed that during seasons when an excep- 

 tional amount of sprout cotton occurs weevil injury has, as a rule, 

 been exceptionally severe. The increased injury during such seasons 

 is imdoubtedly traceable to two primary causes: (1) The climatic 

 conditions which are most favorable to the survival of cotton roots 

 are also as favorable to the survival of hibernating weevils; (2) the 

 large numbers of weevils surviving under these conditions are pro- 

 vided with an abimdant food supply and with, early opportunities 

 for reproduction by the sprout cotton which occurs. 



During winters when the climatic conditions are unfavorable both 

 for the survival of weevils and for the survival of old cotton roots 

 the smaller number of weevils emerging in the spring find no other 

 food supply than that provided by the planted cotton, and can not 

 begin their reproductive activity until such time as the squares upon 

 the planted cotton may be about one-half grown. Under these con- 

 ditions the crop has a fair opportunity to set before weevils become 

 sufficiently abundant to destroy a large proportion of the rapidly 

 forming squares. 



It is difficult to imderstand why so many planters fail to appreciate 

 the importance of preventing entirely the appearance and growth of 

 sprout cotton. The only wa}' in which its occurrence may be posi- 

 tivelv prevented in all seasons and in all parts of the infested area 

 is by the uprooting of the old plants. It is plain that the most effective 

 time to do this, so far as securing a reduction in the number of weevils 

 is concerned, is iimiiediately following 'the maturity and picking of 

 the crop. This prevents further multiplication of weevils at that 

 time and removes the available food supply of those which are adult 

 as long as may be possible before they can hibernate successfully. 

 Extensive experiments and observations have shown that if the 

 stalks be thoroughly destroyed (as by burning) from three to four 

 weeks before the occurrence of the first frost in the fall and if the 

 ground be kept clean, so that favorable opportunities for shcdter 

 are removed, th(* munber of wee^nls surviving hibernation may be 

 very greatly reduced. If by any chance sprout cotton aj)p(>a]-s in 



