Three new compounds, Ciba C-9491 (O-(2,5-dichloro-4-iodophenyl) O, O-dimethyl phosphorothioate), Gardona (2-chloro-l-(2,4, 5-trichlorophenyl) vinyl dimethyl phosphate), and Penick SBP-1382 (5-benzyl-3-furyl) methyl 2, 2-dimethyl-3-(2-methylpropenyl) cyclopropanecarboxylate (ca. 70per thousand trans, 30per thousand cis isomers), all showed greater toxicity than malathion to larvae of the Indian meal moth, Plodia interpuctella (Hübner), in topical-application tests. Gardona was also more toxic than malathion to adult cigarette beetles, Lasioderma serricorne (F.), and confused flour beetles, Tribolium Confusum Jaquelin duVal. Bay 75546 (O-(3-bromo-5, 7-dimethylpyrazolyl(1, 5-a)pyrimidin-2-yl) O,O-diethyl phosphorothioate), Ciba C-9491, and Penick SBP-1382 were all very toxic to larvae of the black carpet beetle, Attagenus megatoma (F.) but were less effective than malathion when comparisons were made at the LD95 level.