title: Mechanisms of resistance to organophosphorus insecticides in populations of the obliquebanded leafroller Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae) from southern Ontario.
abstract: Populations of Choristoneura rosaceana (Harris) from orchards in Ontario were shown to be resistant to azinphos-methyl and to other types of organophosphorus insecticides. Resistance extended to methyl carbamates and to methomyl. The laboratory population used for these assays and selected with azinphosmethyl was also resistant to the pyrethroid, cypermethrin. Resistance was associated with increased esterase activity and was reduced by the addition of the synergist DEF. IEF studies of esterases also indicated increased activity in resistant populations, but did not identify any unique esterases associated with the resistance. Resistance was highly correlated (r = 0.78) with elevated esterases but not with increased glutathione-S transferase activity (r = 0.13). Other mechanisms did not appear to be related.
authors.affiliation: Agriculture & Agri-Food Canada, Southern Crop Protection and Food Research Centre, PO Box 6000, 4902 Victoria Avenue North, Vineland Station, Ontario L0R 2E0, Canada. preed@agr.gc.ca
authors.forename: David J
authors.initials: DJ
authors.lastname: Pree
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Whitty
authors.forename: Lori A
authors.initials: LA
authors.lastname: Bittner
authors.forename: Mitchell K
authors.initials: MK
authors.lastname: Pogoda
mesh_terms: D000818:Animals; D004950:Esterases / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D007915:Lepidoptera / Q000187:drug effects* / Q000201:enzymology; D009864:Ontario; D063086:Organothiophosphates / Q000494:pharmacology; D010574:Pesticide Synergists / Q000494:pharmacology
chemical_list: D007306:Insecticides; D063086:Organothiophosphates; D010574:Pesticide Synergists; C006863:butyl phosphorotrithioate; D005982:Glutathione Transferase; D004950:Esterases