Abstract
A strain of Tribolium castaneum (Herbst) from Georgia was 73-fold resistant to malathion and was highly cross-resistant to phenthoate (× 53), but not to structurally dissimilar carboxylate esters; cross-resistance to any of a variety of other organophosphates, carbamates, chlorinated hydrocarbons or pyrethroids (≤ × 2.7) was not detected. Malathion resistance (Rmal) was inherited as a simple autosomal semidominant trait. Linkage analysis showed Rmal to be located on group VI, 24.6 ± 1.0 map units from Microphthalmic.