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233. Flint, H. M. ; Bibow, W. R. ; and Lahren, C. K. 1966. Radiation studies 

 with the boll weevil: lethal effects on larvae, pupae and adults; male 

 sterility and dose fractionation. J. Econ. Entoraol. 59: 1249-1255. 



Larvae, puape, and adult weevils are very sensitive to X-rays, as measured by 

 adult survival 3 weeks after irradiation. Adult survival of 50-70% 3 weeks 

 atLvir treatment was considered the minimum acceptable. Doses of X-rays that 

 met this criterion were 1200 R for last-in-star larvae, 2A00 R for late-stage 

 pupae, and about 3200 R for adults. In adult weevils, mortality occurred about 

 7-14 days after irradiation, and the death rate did not increase when doses 

 were increased from about 3200 to 15,000 R. Male weevils were 90 and 99% 

 sterilized by doses of about 7500 and 9000 R, respectively. No sterilized 

 male lived more than 3 weeks, and no increase in fertility occurred. In a 

 test with mixed populations of adults irradiated with doses of as much as 

 4800 R, a significant increase in fertility occurred during the 3-week test 

 period, but 5 days after doses of 4000 or more roentgens, egg production was 

 almost eliminated. No increased survival occurred when 8000 R were admini- 

 stered in 4 fractions of 2000 R each to adults at intervals between fractions 

 of as much as 48 hours. Both the lethal and sterilizing effects of X-rays 

 were reduced when weevils in the larval, pupal, and adult stages were sequen- 

 tially irradiated with various fractionated doses. Dose fractionation is 

 not promising as a means of producing a sterile and viable weevil. 



234. ; Earle, N.; Eaton, J; and Klassen, W. 1973. Chemosterilization of 

 the female boll weevil. J. Econ. Entomol. 66: 47-53. 



Forty-three compounds were tested for chemosterilant activity by feeding them 

 to adult Anthonomus grandis Boheman; three compounds, 5 fluorouracil, picolinalde- 

 hyde thiosemicarbazone, and isoquinaldehyde thiosemicarbazone, reduced fecundity 

 to 4% or less of the controls with no hatch of eggs and less than 15% mortality 

 during 1-week posttreatment. Partial recovery of fecundity and fertility 



