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502 



tetramethrin, resmethrin, and pyrethrins were examined for their insecticidal 

 activity to certain cotton insects under laboratory conditions. Included methyl 

 parathion (1:2 ratio) was as toxic as free one to Anthonomus grandis , while the 

 persistency was remarkably improved, almost all remaining after 10 days on cotton 

 leaves under green house conditions. Inclusion did not much reduce the toxicity 

 of methyl parathion to a parasitoid, Campoletis sonorensis , but the possible 

 reduction in use by inclusion may reduce its side effect to natural enemy of 

 cotton pest insects. Pyrethroids were far less toxic to the parasitoid than 

 methyl parathion and the inclusion further improve the safety characteristic. 

 However, higher doses seemed required for included as compared to free pyre- 

 throids to kill Anthonomus grandis . To Heliothis virescens the included methyl 

 parathion was toxic, but pyrethroids were toxic only by contact, and the insect 

 which fed the included pyrethroids seemed not to be affected. 



993. Young, D. F., Jr. 1969. Operation of area-wide diapause programs and 

 results in Mississippi. Proc. 1969 Beltwide Cotton Prod. Res. Conf., 

 pp. 7-9. 

 A reproduction-diapause program was conducted in 1967 in Mississippi in Sharkey 

 County (south Delta) and in Monroe County (eastern Hill area) . The Sharkey 

 County demonstration contained 4,000 acres o^ cotton belonging to 23 farmers. 

 Th©*T4oatee-County area contained 4,000 acres belonging to 79 farmers. Farmers 

 in both areas were asked to add an insecticide to the defoliant and to destroy 

 stalks as early as possible. They were advised to use methyl parathion emul- 

 sifiable concentrate at 0.5 lb. per acre, Guthion ultra low volume at 0.25 lb. 

 per acre or malathion ultra low volume at 1.25 lb. per acre. Farmers were 

 asked to make additional applications at 10 to 14-day intervals following de- 

 foliation. In Sharkey County, no boll weevils were found in the treated area 

 when 12 woods trash samples were taken the following spring. It was not nece- 

 ssary to treat a high percentage of the cotton in the control area for boll 



