title: Susceptibility in field populations of codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), in Ontario and Quebec apple orchards to a selection of insecticides.
abstract: BACKGROUND
  Codling moth is a major pest of pome fruit worldwide. Insecticide resistance has become a widespread pest management issue. However, the current status of insecticide resistance in Ontario and Quebec codling moth populations is unknown.
  
  
  RESULTS
  Codling moth populations were collected from 27 orchards in Ontario and Quebec from 2008 to 2010. A series of laboratory bioassays were performed to establish baseline susceptibility of adults and larvae to azinphos-methyl, thiacloprid, chlorantraniliprole and methoxyfenozide. Adult codling moth percentage mortality ranged from 22 to 97% and from 21 to 85% when exposed to topical bioassays using azinphos-methyl and thiacloprid respectively. Azinphos-methyl LC50 values from three selected orchards were ca fivefold greater than those from an insecticide-susceptible population. Neonate larva percentage mortality ranged from 5 to 50%, from 15 to 65%, from 90 to 100% and from 10 to 40% when exposed to diet bioassays using azinphos-methyl, thiacloprid, chlorantraniliprole and methoxyfenozide respectively.
  
  
  CONCLUSIONS
  Based on the response of the field-collected populations, resistance development to some registered insecticides was evident in some Ontario and Quebec populations. With the present status of insecticide resistance documented in these regions, modifications to codling moth management strategies should be initiated before changes in field efficacy occur.
authors.affiliation: School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Kristy
authors.initials: K
authors.lastname: Grigg-McGuffin
authors.forename: Ian M
authors.initials: IM
authors.lastname: Scott
authors.forename: Sylvie
authors.initials: S
authors.lastname: Bellerose
authors.forename: Gérald
authors.initials: G
authors.lastname: Chouinard
authors.forename: Daniel
authors.initials: D
authors.lastname: Cormier
authors.forename: Cynthia
authors.initials: C
authors.lastname: Scott-Dupree
mesh_terms: D000818:Animals; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D027845:Malus; D009036:Moths / Q000187:drug effects* / Q000254:growth & development; D009864:Ontario; D011792:Quebec
chemical_list: D007306:Insecticides
keywords: Cydia pomonella; azinphos-methyl; chlorantraniliprole; insecticide resistance; methoxyfenozide; thiacloprid