2A2 



sterility in all males and permanent sterility in 97% of the males, and it 

 drastically reduced the fecundity of females. The cumulative mortality at 3 

 weeks posrtreatment was moderate. In at least 4 consecutive matings, each 

 treated male displaced normal sperm in a previously mated female. The 

 production of pheromone by treated males was normal. 



469. ; Knipling, E. F.; and McGuire, J. U., Jr. 1970. The potential for 

 insect-population suppression by dominant conditional lethal traits. 

 Ann. Entomol. Soc. Am. 63: 238-255. 

 Calculations are presented to show the possibility of suppressing insect popu- 

 lations by overflooding a native population with individuals bearing dominant 

 conditional lethal traits. If a conditional lethal trait is determined by a 

 single dominant factor fully penetrant in the heterozygotes, then a native 

 population of 100 insects per acre could be eradicated by 3 releases of 12 

 mutants for every insect in the native population. Comparable results would 

 be achieved with a polyfactorial conditional lethal trait if the hybrids 

 differed from the native population. Since inability to diapause is con- 

 sidered to be an ideal conditional lethal trait for control, hypothetical 

 population models were worked out to determine the impact of releasing boll 

 weevils, Anthonomus grandis Boheman, carrying an assumed dominant nondiapause 

 trait. If a natural population were reduced by a special schedule of treat- 

 ments with insecticides to 1 male and 1 female per acre and then overflooded 

 by a factor of 99 of each sex, all carrying the dominant conditional lethal 

 trait, the overwintering population (F, generation) would be reduced by 99.99%, 

 This reduction would constitute practical eradication. An alternate procedure 

 Involving the use of a similar nondiapausing strain that was partially steri- 

 lized by irradiation or chemosterilants would avoid economic damage to cotton 

 pending the final eradication of the pest by the conditional lethal trait. 



X 



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