■ Mwiiic— iW liwiirtii mnimm/mitma^tiM 



487 



sterility and red stem. The 3 characters were cumulative in imparting non- 

 preference and, to some extent, in reducing hatchability. Lint yield of some 

 strains with multiple nonpreferred characters was equal to 'Coker 201' in a 

 yield test grown under adequate insect control and was significantly higher 

 where no insecticides were applied. 



962. Weidhaas, D. E. 1968. Field development and evaluation of chemosterilants. 

 In Principles of Insect Chemosterilization, G. C. La Brecque and C. N. 

 Smith (Eds.), pp. 275-314. Appleton-Century-Crofts, New York. 



An extensive effort on the laboratory development and evaluation of chemosteri- 

 lants had led to preliminary field testing of chemosterilants with;;a variety of 

 insect species and different methods of utilizing these materials. This research 

 is summarized by insect species which have been studied including house flies, 

 screwworm, Mexican fruitfly, mosquitos, cabbage" looper, boll weevil, pink boll- 

 worm and codling moths. 



963. Wendell, L. E., and Bull, D. L. 1970. Systemic activity and metabolism 



of dimethyl £;-(methlythio) phenyl phosphate in cotton. J. Agric. Food Chem. 



18: 420-424. 



32 

 Studies were made of the fate of P-labeled dimethyl £- (me thy Ithio) phenyl phos- 

 phate (Allied Chemical Co. compound GC-6506) in field-gro\m cotton after diffe- 

 rent methods -of treatment. GC-6506 was oxidized very rapidly in plants to the 

 sulfoxide form and more slowly to the sulfone. The oxidative derivatives were 

 shown to be more active than GC-6506 as anticholinesterase agents, but were 

 slightly less toxic to adult boll weevils, Anthonomus grandis Boheman, after 

 topical application. GC-6506 applied to the main stems of cotton plants was 

 absorbed readily and translocated to all parts of the plant except the fruit. 

 The compound also was absorbed rapidly a£ter application to the surfaces of the 

 leaves. The biological half-lives of GC-6506 and its oxidative derivatives inside 



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