—-.rjT'Kac 



488 



the plant did not exceed two days, and all toxicants were usually depleted after 

 four weeks. The degradation of toxic compounds involved cleavage of the 0-methyl 

 and P-0-phenyl linkages. 



964. White, J. R. , and Rummel, D. R. 1978. Emergence profile of overwintered 



boll weevils and entry into cotton. Environ. Entomol. 7; 7-14. 

 Small plots of cotton and pheromone traps were used to study the emergence pro- 

 file of overwintered boll weevils, Anthonomus grand is Boheman, and their entry 

 into cotton. Boll weevil movement into cotton was closely related to the pheno- 

 logy of the plant. Very few overwintered weevils entered presquaring cotton but 

 immigration increased with increasing size and number of squares. Results of 

 this study indicate that overwintered weevil colonization is not a result of 

 random entry into cotton followed by pheromone production. Rather, overwintered 

 weevil immigration into cotton appears to be a positive response to squaring 

 cotton, with atcraction greatly intensified by pheromone production after wee- 

 vils feed on squares. Overwintered weevil response to pheromone traps appeared 

 to provide a relatively accurate index of population size and activity. In 

 the study area pheromone traps indicated that the major portion of the over- 

 wintered population was active several weeks before weevil colonization occurred 

 in cotton. These data indicated that ca. the«last 10% of boll weevils emerging 

 fro?^.-cvsrwlntering habitat contributed the major portion of the population 

 that entered cotton. The relationship between the number of weevils responding 

 to pheromone traps and the number entering the cotton plots indicates that 

 pheromone traps can be used to predict the degree of overwintered boll weevil 

 infestation which will occur in cotton. 



965. ; Rummell, D. R.; and Wade, L. J. 1977. A new concept in boll weevil 



pheromone trap design. Southwest. Entomol. 2: 37-41. 

 A new type of boll weevil pheromone trap was developed and tested during the 





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