A rigid program of insecticide treatments would not, according to the assump- 

 tions, achieve eradication, although the population would be reduced to an average of 

 about 1 boll weevil per acre in the Fg generation. Failure to show elimination of a 

 population by the use of insecticides alone is reportedly in agreement with general 

 observations in practical control of boll weevils during the regular growing season. To 

 the writer's knowledge, however, no full-season insecticide program of the type pro- 

 jected in the model has ever been carried out against a completely isolated boll weevil 

 population , 



In contrast with the calculated effect of using an insecticide program alone, the 

 population subjected to sterile males instead of insecticides in the F^ , F , and F„ 

 generations, shows a dramatic decline, and theoretical eradication of the population is 

 achieved in the F^ generation by a wide safety margin. 



The writer recognizes that it is not yet possible to produce fully competitive 

 sterile males, but if sterile males eventually can be produced that are even one-third to 

 one-half competitive, it should be possible to eliminate a low-level population — about 10 

 or less per acre — within three generations by using a total of about 1, 000 sterile males 

 per acre. If this can be achieved, the sterile-insects technique will be a highly econom- 

 ical method for boll weevil eradication when considered in relation to current costs for 

 control and losses that occur in spite of control efforts. 



Cost Analysis 



It may be appropriate to make a cost analysis of the two systems of control pro- 

 jected in model 9. The full-season insecticide regime, as projected, would require 18 

 treatments. At a cost of $2 per treatment, the total per-acre cost would be $36. 

 Theoretically, however, complete population control would not be achieved. It is not 

 uncommon for cotton growers under current practices to apply 18 treatments each 

 season for boll weevil control. 



The integrated sterile-insect-release and insecticide program, theoretically, 

 would require 7 insecticide treatments and enough sterile male boll weevils to maintain 

 an average population of 300 per acre during the F-. generation, 200 per acre during the 

 Fg generation, and 100 per acre during the Fo generation. If we assumed that 1,000 

 sterile males actually would be required, and if $5 per 1, 000 would be a reasonable 

 estimate for the mass production and release of this insect, the total material and 

 application cost for eliminating boll weevil populations would be $19 per acre. Many 

 growers exceed this sum each year merely for boll weevil control using current methods , 



To project the cost analysis even further, an average cost of $19 per acre on 10 

 million acres would amount to $190 million. This would not include any other costs of 

 an operational program. This estimate is purely h3^othetical because all of the pro- 

 jections are hypothetical. Nevertheless, the potential possibilities are projected on the 

 basis of a conservative analysis of the boll weevil problem in relation to the potentiali- 

 ties of the sterility principle. A fully integrated program of insecticides and sterile 



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