37 



only slowly from 39 to 8.8 yg/weevll within 7 days. Ovlposition of untreated 

 females mated to treated males was decreased; also, treated males were less 

 effective th^n untreated ones in transferring sperm. On the other hand, v;hen 

 various ratios of treated and untreated males were combined with untreated 

 females, the treated males appeared more competitive because they suppressed 

 reproduction more effectively than their proportional number would warrant. 

 The development of the new sterilizing procedure now makes it possible to test 

 the performance of chemosterilized weevils in large field tests. 



64. Bottrell, D. G. 1968. Comparative effectiveness of mala.thion and 

 azinphosmethyl applied as ultra-low-volume sprays in a fall boll 

 weevil control experiment. Tex. Agric. Exp. Stn. Prog. Rep. PR-2543, 

 7 pp. 



Two rates of each malathion and azinphosmethyl were applied six times as ultra- 

 low-volume aerial sprays in a fall boll weevil control experiment in Stonewall 

 County, Texas. Azinphosmethyl at the rate of 0.25 pound active toxicant per 

 acre provided slightly more effective weevil control than azinphosmethyl at 

 0.19 pound per acre. The lower rate of azinphosmethyl was about equal in effec- 

 tiveness to malathion at 1.21 pound per acre. Percentage diapause in weevils 

 remaining at the end of the experiment was about the same in all four treatments. 



65. . 1973. Using grandlure to manipulate overwintered boll weevil popu- 

 lations into restricted sites within cotton fields. Folia Entomol. 

 Mex. 25-26: 74-75. (In Spanish). 



Results from research conducted in the Rolling Plains of Texas, 1971, demon- 

 strated a principle of using glandiure, the synthetic pheromone of the male 

 boll weevil, Anthonomus grand is Boheman, to manipulate adult overwintered 

 populations of the species into restricted sites within cotton fields through 

 use of traps baited with grandlure. 



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