61 



parisons of the efficacy of the BT formulations (561 g/ha) and a commercial 

 formulation of Baculovirus heliothls (BH) (148 g/ha) against moderate populations 

 of larvae. When the BH formulation (148 g/ha) or the BT formulation (560 g/ha) 

 was applied in conjunction with releases of Trichogramma (110,000/ha) in test 

 plots oversprayed with dif lubenzuron (70 g + 4.7 liter crop oll/ha) to control 

 boll weevils, Anthonomus grandls grandis Boheman, the 2 microbial pesticides 

 caused a similar and significant reduction (compared with the check) in the 

 numbers of both small and large Heliothis spp. larvae. Numbers of undamaged 

 bolls were also significantly greater in microbial-treated plots. 



106. , and Lindquist, D. A. 1966. The effects of chronic doses of an 

 organophosphorus inhibitor on cholinesterase activity in boll weevils. 

 Experiments 21: 262-263. 



Though absolute proof has not been established, the consensus of most workers 



is that cholinesterase (ChE) inhibition is the primary biochemical lesion 



1 2 

 leading to the death of insects poisoned by organophosphorus (OP) insecticdes ' . 



Effects of OP poisoning on mammalian ChE have been reported in some detail, but 



information on chronic effects in insects is limited. As part of a general 



investigation of systemic, OP insecticides in cotton plants, we examined changes 



in the ChE activity of adult boll weevHs ( Anthonomus grandis Boheman) that 



received sustained doses of Bidrin (3-hydroxy-N, N-dimethyl -^is- crotonamide 



dimethyl phosphate) in their diet. 



107. , and Lindquist, D. A. 1966. Insect metabolism: metabolism of 3-hydroxy- 

 N-methyl -cis- crotonamide dimethyl phosphate (Azodrin) by insects and 

 rats. J. Agric. Food Chem. 14: 105-109. 



Oxidative conversion of Azodrin (3-dydroxy-N-methyl-cls-crotonamide dimethyl 

 phosphate) to its N-methylol derivative occurred in five species of insects, 

 boll weevil ( Anthonomus grandis Boheman). housefly ( Musca domestl ca Linnaeus), 



X 



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