203 



wings only with topical treatment. Radioactivity detected in the spermathecae 

 of females D^ted to treated males gave presumptive evidence that the aperui 

 was labeled. About 85% of the initial radioactivity was detected in feces, 

 expired CO2, other expired volatiles, and body of injected insects after 

 2 days. Of the residual radioactivity in the body at 2 days, more than 

 85Z was bouml by constituents with low molecular weight. 



39A. ; Wiygul, G.; Vickers, D. H.; Bartlett, A. C; and Mitlin, N. 



1967. Sterility induced by tepa in the boll weevil: effective dose 

 and pernanency, gonadal changes, and biological turnover of labeled 

 compound. J. Econ. Entomol. 60: 209-214. 

 The male boll weevil, Anthonomus grandis Boheman, was sterilized with tepa, 

 either by feeding 1500 ppm in the diet for 2 days or by an injection of 3.5 

 yg. Lower levels produced transitory steriliztaion. At the effective levels, 

 mortality was significant. A recovery of fertility occurred about 5 days 

 after treatment at the 1.5-vig level. This recovery was less marked with 

 an artificial diet than with cotton buds. In a study of single pairs 12 

 of 27 males, surviving treatment at the l.O-pg level, regained fertility 

 within 36 days. Decreases in the size of the testes and changes in morpho- 

 logy and cytology occurred. The radioactivity of insects treated with 

 C^ -labeled tepa was decreased by half in 6-A8 hours, depending on the 

 diet, but 10-2&2 was retained for at least 10 days. No differences related 

 to posttreatraent diet were observed. Nitric acid was employed for digestion 

 of insect tissue prior to C-*-^ gas-flow counting. Conditions are described 

 for reproducible and near-quantitative counting of the isotope. 



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