Plodia interpunctella and Cadra cautella Resistance in Strains to Malathion and Synergized Pyrethrins13

Abstract
Strains of the Indian meal moth, Plodia interpunctella (Hübner), and the almond moth, Cadra cautella (Walker), Collected in 1971 and 1972 from peanut- and grain-storage Facilities, had a range of resistance to malathion and Synergized pyrethrins. Resistance to malathion in 6 strains of C. cautella ranged from 1.2 to 7.2; that in 7 strains of P. interpunctella ranged from 177 to at least 206. Two strains each of P. interpunctella and C. cautella showed low levels of resistance to synergized pyrethrins.