Susceptibility of Tribolium castaneum (Herbst) adults to non-pyrethroid insecticides.
In India, 10 non-pyrethroid insecticides were evaluated against adults of the rust red flour beetle (Tribolium castaneum) by direct spray and film residue bio-assay methods. Methyl parathion was the most toxic insecticide, irrespective of the application method used. Fenitrothion and dimethoate were much more toxic as direct sprays than as film residues, while toxicity of the remaining insecticides was comparable when used either by the direct spray or film residue method. In the case of malathion, resistance ratios obtained by the direct spray method were comparable with those obtained by the film residue method (18.00 and 18.82, respectively). Between 1970 and 1996, a pronounced shift in the level of susceptibility of red flour beetle adults to all organophosphates was observed. KEYWORDS: TROPAG | stored products pests | Tribolium castaneum | insecticides | organophosphorus compounds | chemical resistance | insect control | INDIA.