24A 



mortality could be induced in Anthonoraus grandis Boheman. Adult boll weevils 

 irradiated with 2.5 krad of X-rays and immersed in a 1.0% solution of apholate 

 within 8 hours had a greater cumulative percentage mortality at 3 weeks than 

 when the 2 treatments were separated by several days. However, the treatments 

 failed to destroy completely the germarium in all males. Destruction of the 

 germarium occurred more frequently if the males were still soft bodied when 

 they were immersed. Thus, when 2-day-old males were Immersed in apholate and 

 X-irradiated 80 hours later, the majority sustained permanent destruction of the 

 germarium. Weevils treated with 2.5 krad of y-rays and a 1.0% solution of apho- 

 late reestablished the spermatogenic cycle as early as 13 days later and usually 

 within 3 weeks; in 1 test, recovery of fertility occurred 11-13 days after treat- 

 ment, and in 2 other tests, recovery occurred at lA-16 days after treatment. 

 Sublethal doses of thermal neutrons did not sterilize boll weevils, but 1 krad 

 of fast neutrons significantly reduced the fertility of treated males and the 

 fecundity of treated females. Doses of fast neutrons greater than 1.2 krad 

 caused high mortality, but a dose of 2 krad was necessary to sterilize all sperm 

 and destroy all spermatogonia. Fecundity of treated females was greatly reduced 

 with 1.5 and 2 krad. However, their fertility was depressed only moderately. 

 Irradiation of either sex with 1 krad of fast neutrons and immersion 3 days 

 later in a 1.0% solution of apholate resulted in almost complete sterility, 

 though the spermatogenic cycle was re-established in some individuals at 4 weeks 

 after treatment. Moreover, this treatment reduced mating competitiveness of 

 males treated as adults less than treatment with 2.5 krad Y~rays and a 1.0% 

 solution of apholate. 



473. Knipllng, E. F. 1966. Population models to test theoretical effects 

 of sex attractants used for insect control. U.S. Dep. Agric. Inf. 

 Bull. 308, 20 pp. 



Entomologists have shown fhat males of many insect species will contact or 



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