Abstract
The toxicity, metabolism, and absorption of several selected insecticides were compared between methyl parathion-susceptible (S) and -resistant (R) strains of the tobacco budworm (Heliothis virescens (F.)) to assess the influence of detoxification and absorption in the resistance exhibited by the R larvae. In addition, the relationships of certain chemical structures of dialkyloxy arylphosphate compounds to toxicity, metabolism, and absorption were evaluated. Toxicity tests made with 3rd-stage larvae indicated that the R larvae were resistant (as evidenced by a 5-fold or greater increase in the LD [subscript 50] value of an insecticide as compared with that from S larvae) to methyl parathion, methyl paraoxon, paraoxon, parathion, and fospirate, but not to chlorpyrifos, chlorpyrifosmethyl, or Dowco [superscript R] 180. Those compounds containing dimethoxy groups were more toxic than their corresponding diethoxy homologues to larvae of both strains.
Whitten, Chandler James (1975). Factors influencing organophosphorus insecticide resistance in tobacco budworms. Doctoral dissertation, Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -182039.