Relative Susceptibility of Five Stored-Product Moths to Some Organophosphorus Insecticides12

Abstract

The relative susceptibility of the almond moth (AM), Cadra Cautella (Walker); Indiao-meal moth (IMM), Plodia interpunclella (Hubner); Mediterranean flour moth (MFM), Anagasta huchniella (Zeller); raisin moth (RM), Cadra figulilella (Gregson); and tobacco moth (TM), Ephestia elutella (Hubner); to each of 12 organophosphorus insecticides was determined by direct application of spray solutions to adult insects. Various degrees of differences in susceptibility were observed among and the range of differences varied with insecticides. The order of species susceptibility at LC95, to each insecticides tested was: Abate ® (O, O -dimethyl phosphorothioate O, O -diester with 4,4′-thiodiphenol), MFM> AM>TM>RM>IMM; Bay 77488 (O, O -diethyl phosphorothioate O-ester with phenylglyoxylonitrile oxime), AM = AFM>IMM>TM>RM; Bay 78182 >(O, O -diethyl phosphorothioate O-ester with o -chlorophenyl) glyoxylonitrile oxime), AM>IMM>TM>RM>MFM; C-9491 (0 -(2,5-di-chloros-4-iodophenyl) O, O -dimethyl phosphorothioate), AM>TM>MFM>RM>IMM: diazinon, MFM>TM>AM= IMM>RM; dicapthon, MFM>TM>RM>IMM>AM; dimoth chlorvos, MFM>IMM>TM>RM>AM; Dursban® (O, O- diethyl 0-3,5,6-trichloro-2-pyridyl phosphorothioate), MFM>AM>RM>TM>IMM; fenitrothion (Bay 41831) (O, O-dimethyl o -4-nitro-m-tolyl phosphorothioate), MFM>RM>AM>TM>IMM; fenthion, IMM>IMM>AM> TM>AM>RM; Gardona® (2-chloron 1-(2,4,5-trichlorospecies, phenyl) vinyl dimethyl phosphate), MFM>IMM>AM> Using a basis of 1 for the most toxic compound, the order and rank in relative effectiveness of insecticides indicated by ratios calculated from LC95 values obtained for the least susceptible of the 5 species of moths to each of the insecticides tested were: dichlorvos, 1.0; Bay 77488, 2.4; Bay 78182, 3.9; Dursban, 7.6; diazinon, 8.0; fenthion, 8.3; malathion, 9.2; fenitrothion, 13.9; Gardona, 47.5; C-9491, 58.7; dicapthon, 362.3; and Abate, 47.1.