Boll weevil prepares to feed on a "square, " or bud, of a cotton plant. Females deposit eggs 

 within cotton squares and immature "bolls, " or fruits, which the weevil larvae consume and 

 ultimately destroy. 



from ten states, and it is in retreat in seven more. 

 Unfortunately, the principal weapons in this war 

 have been chemical insecticides, some ot which, es- 

 pecially initially, have left toxic residues that are like- 

 ly to persist for many years. 



A second untortunate reality is that much of the 

 war against the boU weevil had to be fought with- 

 out knowing the biological history of the enemy — 

 where it came from or why. The mystery can be 

 traced to an obscure taxonomic error. Correcting 

 that error eventually led to a vastly improved un- 

 derstanding of the weevil's natural history, but that 

 understanding came too late to have much impact 

 on the U.S. eradication effort, hi fact, the success of 

 the eradication effort led to cuts in spending on re- 

 search into alternate methods of weevil control. Does 

 that mean the enhanced knowledge is of no more 

 than academic interest? Quite the contrary. The boll 

 weevil may be in retreat in the U.S., but it remains 

 a key cotton pest in Mexico and Central America. 

 In those countries the presence of the weevil's wild 

 host plants may make it futile to apply U.S. eradica- 



tion methods. More worrisome is that the insect has 

 opened a second front in South America. That in- 

 vasion continues mounting to this day. Understand- 

 ing the boll weevils origins, its natural enemies, and 

 the defenses that relatives of cotton might have 

 evolved against its ancestors may one day help re- 

 duce the need for pesticides to control it. 



As early as 1862, some thirt)'-two years before 

 Charles DeRyee's alert, the boU Vv'eevil had al- 

 ready been reported destroying cotton plants in what 

 were then wild and isolated regions of Mexico's 

 northern states. That earlier report caused little stir 

 in the U.S. By 1900, however, the weevil was well 

 entrenched in southern Texas and plainly displaying 

 its destructive potential. A growing alarm was spread- 

 ing among cotton growers throughout the South. 



And with good reason. Between 1892 and 1922 

 the boll weevil advanced relendessly by 40 to 200 

 miles a year \scc map on next pa^c]. By 1916 it had 

 reached the Atlantic seaboard, and five years liter it 

 had spread throughout the Cotton Belt, ho\u west 



February 2006 NATUK.AI lllSTt'KV 31 



