110 



Davich 1966). Also, the male placed in the traps were dyed red internally by 

 incorporating Calco Oil Red N-1700® in the larval diet. The acetone-paper 

 strip method of identifying insects marked with the dye was used on all cap- 

 tured boll weevils to determine whether they were sterile males that had 

 escape(L, or native weevils. Traps were checked, and fresh males and food 

 were provided at least once a week. Between Oct. 2 and 22, 1968, 11 boll 

 weevils: (4 c5, 7 9) were captured on traps 25 miles from cotton, 3 (1 <^, 2 9) 

 36 miles from cotton, and 1 (<J) A5 miles from c tton. All were dissected, 

 checked for dye, and found to be dark gray, reasonably fat, and negative for 

 dye; thus, they were unquestionably native boll weevils. Although the traps 

 were operated from July 22 through Nov. 7, all captures were made in the 

 first 3 weeks of October. 



205. ; Merkl, M. E.; Mitchell, E. B.; Hardee, D. D.; Cast, R. T.; McKibben, 

 G. H.; and Huddleston, P. A. 1967. Field experiments with sterile 

 males for eradication of the boll weevil. J. Econ. Entomol. 60: 1533-1538. 

 From June 17 through August 26, 1964, 11 weekly releases of apholate-sterilized 

 male boll weevils, Anthonotnus grandis Boheman, were made in 9 cottonfields, 

 (15.8 acres) that had been treated with insecticides the fall of 1963 to 

 reduce the population of diapausing weevils. These weekly releases ranged 

 from 3270- to 26,620 sterile weevils per acre (an average of 8200 per acre). 

 Migrant weevils entering the release zone from other areas may have caused the 

 program to achieve population suppression rather than eradication, though the 

 release zone was surrounded by a 120-acre zone that had received the same fall 

 treatment and was treated intensively with insecticides in 1964 and by another 

 115-acre buffer zone that was treated with insecticides in 1964. However, the 

 apholate sterilized only an average 95.8% of the weevils and caused a substan- 

 tial reduction in mating competiti isss. The release of the sterile males 

 against the low-level population achieved by the 1963 fall applications reduced 



