Abstract
The toxicity of several insecticides to two local strains of
S. oryzae and
T. castaneum was determined by exposure to treated papers or wheat. Malathion, lindane, dichlorvos and diazinon were more toxic than DDT, carbaryl and pyrethrins. The
S. oryzae strain was very susceptible to lindane (0·43×) and malathion (0·26×), but the
T. castaneum strain was found to be tolerant to lindane (1·95×) and malathion (7·6×). The
T. castaneum was more tolerant to all tested insecticides than the
S. oryzae strain.