243 



In this hypothetical model, a small natural population would be Initially 



overflooded 99:1, and such releases would be continued for 4 generations. 



/ 

 The natural population would be effectively suppressed by sterility while / 



the dominant conditional lethal genes were being introduced into the natural 



population often enough to assure extnction of the population during the 



winter. The estimated costs show that it will be entirely practical to use 



these genetic methods for eradication if they can be perfected. 



470. , and Norland, J. F. 1967. Sterilization of the boll weevil. Proc. 

 N.C. Branch Entomol. Soc. Am. 22: 140. 



When fed to "ale weevils for three days methane sulfonic acid, tetramethylene 

 ester induced sexual sterility with little mortality. Several aziridinyl com- 

 pounds induced a high degree of sterility, however some mortality supervened. 

 Certain structure-activity relationships are detailed. 



471. ; Norland, J. F. ; and Borkovec, A. B. 1968. Potential chemosterilants 

 for boll weevils. J. Econ. Entomol. 61: 401-407. 



Methanesulfonates, nitrogen mustards, aziridines, phosphoramides, ^-triazines, 

 and miscellaneous chemicals were evaluated for chemosterilant activity by feeding 

 them to male boll weevils, Anthonomus grandis Boheman. Sterility without morta- 

 lity was induced by busulfan (ENT 25012) (fr,4-butanediol, diraethanesulfonate) ; 

 <iKJ?~51904 (1,3-propanediol, diraethanesulfonate), chlorambucil (E^T 26083) (4(£- 

 [bis(2-chloroethyl)amino]phenyl)-butyric acid); ENT 51007 (N.N.N' ,N'-tetramethyl- 

 p-piperidino-phosphonic diamide); and several aziridines, the most promising 

 being the cyclic diester of pentaerythritol and I-aziridinylphosphonic acid. 



472. ; Norland, J. F. ; and Briggs, R. W. 1969. Sterilization of boll 

 weevils with combinations of chemosterilants and X-rays, gamma rays, 

 thermal neutrons, or fast neutrons. J. Econ. Entomol. 62: 1204-1216. 



This study was undertaken to determine whether satisfactory sterility without 



