seems desirable to discuss this question to some extent. There is much that is not 

 known about the effect of polygamy among insects , and the influence such a mating habit 

 will have on the effectiveness of the sterility method. However, it can now be stated 

 with assurance that a polygamous mating habit does not rule out the sterile-insect-release 

 method as a practical approach to insect control and eradication. In fact, under certain 

 circumstances, polygamy could be an advantage in the application of the method. There 

 are several reasons why it is valid to conclude that polygamy is of no adverse conse- 

 quence. The radiation method of producing sterility does not prevent the production of 

 sperm in the male. This was determined by R. C. Bushland and D. E. Hopkins in their 

 early work. They observed that eggs produced by normal females mated to irradiated 

 males were fertilized but did not hatch. The radiation produces a dominant lethal effect. 

 It has been shown by several investigators that chemosterilants , now under investigation, 

 affect sperm in a similar manner. Thus, if we can assume that sperm in sterilized 

 males are present in adequate numbers, and if they are reasonably competitive with 

 sperm of normal males, we have a valid basis for assuming that polygamy is not an 

 adverse factor. 



We might establish a model in support of the hypothesis stated, by assuming that 

 we have two tjrpes of insects — one that mates once only, and the other that mates an 

 average of 10 times . If the sterile males in the population produce the same number of 

 sperm, and if the sperm are fully competitive in the spermatheca of the female, the 

 overall effect on the reproductive potential of the entire population will be the same. 

 Note model 7. 



Model 7 . — The relative effect of sterile-insect releases on the reproductive potential of 

 two hypothetical insect populations when one species is monogamous and the 

 other is polygamous in mating behavior. It is assumed that both the sterile 

 male insects and the sperm they produce are fully competitive with normal 

 fertile males 



Mating 



Number of insects in 



Percentage of females 



Percentage of sterile 



behavior 



the total population 



mating with sterile 



eggs in total population 









males 







Sterile 



Fertile 

 10 



90 





Monoga- 



90 



90 



mous 











Polyga- 



90 



10 



All females on average 



On an average, 90 



mous 







mate with 9 sterile males 



percent of the eggs are 



(average of 







and 1 fertile male 



sterilized and 10 percent 



10 matings) 









are fertile 



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