caa a22 4500 388036125 CHVBK 20180307125005.0 cr unu---uuuuu 161130e199804 xx s 000 0 eng 10.1017/S0007485300025761 doi S0007485300025761 pii (NATIONALLICENCE)cambridge-10.1017/S0007485300025761 Malathion-specific resistance in a strain of the rust red grain beetle Cryptolestes ferrugineus (Coleoptera: Cucujidae) [Elektronische Daten] A strain of Cryptolestes ferrugineus (Stephens) bred for malathion-specific resistance was found to be 650 fold resistant at LD50 when compared with a susceptible strain bred from the same stock. Resistance was more than 98% synergized by triphenyl phosphate and S,S,S-tributyl phosphorotrithioate, but unaffected by piperonyl butoxide. AChE inhibition by malaoxon varied slightly between the strains. Non-specific esterase activity as measured by the hydrolysis of α-naphthyl acetate was slightly reduced in the resistant strain whereas there were no inter-strain differences in the hydrolysis of β-naphthyl acetate. Products of in vitro metabolism of malathion were identified by thin-layer chromatography and gas chromatography-mass spectrometry as α- and β-malathion mono-acids. It was therefore concluded that resistance was due to the hydrolytic breakdown of malathion by a malathion-specific carboxylesterase. The rate of in vitro malathion hydrolysis was found to be 31 times greater in the resistant strain. In vitro inhibition studies indicated that resistance is attributable to a carboxylesterase unique to the resistant strain. The implications of these results are discussed in relation to work recently carried out on malathion-specific resistance in dipterous species. Copyright © Cambridge University Press 1998 Spencer A.G. School of Animal and Microbial Sciences, University of Reading, Reading, Berkshire, RG6 6AJ, UK Price N.R. Ministry of Agriculture Fisheries and Food, Central Science Laboratory, Sand Hutton, York, YO4 1LZ, UK Callaghan A. School of Animal and Microbial Sciences, University of Reading, Reading, Berkshire, RG6 6AJ, UK Bulletin of Entomological Research Cambridge University Press 88/2(1998-04), 199-206 0007-4853 88:2<199 1998 88 BER https://doi.org/10.1017/S0007485300025761 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0007485300025761 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Spencer A.G. School of Animal and Microbial Sciences, University of Reading, Reading, Berkshire, RG6 6AJ, UK NATIONALLICENCE 700 1- Price N.R. Ministry of Agriculture Fisheries and Food, Central Science Laboratory, Sand Hutton, York, YO4 1LZ, UK NATIONALLICENCE 700 1- Callaghan A. School of Animal and Microbial Sciences, University of Reading, Reading, Berkshire, RG6 6AJ, UK NATIONALLICENCE 773 0- Bulletin of Entomological Research Cambridge University Press 88/2(1998-04), 199-206 0007-4853 88:2<199 1998 88 BER CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge