418 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1958 
established infestations by the use of chemicals or other means; (8) 
as a means of eradicating incipient infestations; (4) as a means of 
preventing further spread of insects that have not yet reached the 
limits of the survival area; (5) as a means of preventing or retard- 
ing spread of pests from overwintering areas. 
For an appraisal of the possibilities of this new approach to insect 
control, investigations must be conducted along the following lines: 
(1) The effect of atomic irradiations on the reproductive capacity 
of the insects; (2) the effects of the irradiations on length of life and 
sexual behavior of the insect; (3) the mating habits of the insect; (4) 
population studies, with particular reference to actual numbers of 
insects in a given area during low points in the seasonal cycle or in 
areas of new establishment; (5) the biotic potential or normal rate 
of increase per generation under natural conditions; (6) the nutri- 
tional requirements of insects, with particular emphasis on the develop- 
ment of economical means for mass production; (7) the flight range 
and dispersal habits of insects; and (8) methods of separating sexes 
at low cost for species in which the released females may cause excessive 
damage. 
These investigations will by no means supply answers to all ques- 
tions that might arise in considering the possible use of sterile males 
for controlling specific pests. 
However, until we obtain such information we cannot forecast just 
how useful the method will be in dealing with insect problems in the 
United States and in other parts of the world. There is every reason 
to believe that this new approach to insect control is sufficiently 
promising to warrant exploration for many of our major insect pests. 
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Baumnover, A. H.; GRAHAM, A. J.; Hopkins, D. E.; Duptey, F. H.; New, W. D.; 
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1955. Control of screwworms through release of sterilized flies. Journ. 
Econ. Entomol., vol. 48, No. 4, pp. 462-466. 
BUSHLAND, R. C., and Horpxins, D. E. 
1951. Experiments with screwworm flies sterilized by X-rays. Journ. Econ. 
Entomol., vol. 44, No. 5, pp. 725-731. 
1953. Sterilization of screwworm flies with X-rays and gamma-rays. Journ. 
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Knrerina, E. F. 
1955. Possibilities of insect control or eradication through the use of 
Sexually sterile males. Journ. Econ. Entomol., vol. 48, No. 4, 
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LINpDQuIsT, A. W. 
1955. Possibilities on the use of gamma radiation for control of eradica- 
tion of the screwworm. Journ. Econ. Entomol., vol. 48, No. 4, 
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MELVIN, Roy, and BUSHLAND, R. C. 
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