title: Cross-resistance and genetics of resistance to indoxacarb in Spodoptera litura (Lepidoptera: Noctuidae).
abstract: Bioassays (at generation G1) with a newly collected field population of Spodoptera litura (F.) (Lepidoptera: Noctuidae) from Multan, Pakistan, showed resistance ratios of 15, 23, 37, and 16 for indoxacarb, spinosad, abamectin, and emamectin, respectively, compared with a laboratory susceptible population, Lab-PK. At G1, the field population was selected with indoxacarb by using single pair crosses. For Indoxa-SEL, bioassay at G4 found that selection increased resistance ratio to 95 for indoxacarb compared with Lab-PK. Selection with indoxacarb significantly increased resistance to spinosad and emamectin; however, resistance to abamectin was observed to drop. A significant reduction in the resistance to indoxacarb was observed in Indoxa-SEL at G9, indicating unstable resistance to indoxacarb; however, it was stable for fipronil. Synergism tests with microsomal oxidase and esterase-specific inhibitors suggested that the indoxacarb resistance was associated with microsomal oxidase. Reciprocal genetic crosses between Indoxa-SEL and Lab-PK populations indicated that resistance was autosomal and incompletely dominant. Tests of monogenic inheritance suggested that resistance to indoxacarb was controlled by more than one locus.
authors.affiliation: Department of Biochemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, United Kingdom. h.a.sayyed@sussex.ac.uk
authors.forename: Ali H
authors.initials: AH
authors.lastname: Sayyed
authors.forename: Munir
authors.initials: M
authors.lastname: Ahmad
authors.forename: Mushtaq A
authors.initials: MA
authors.lastname: Saleem
mesh_terms: D000818:Animals; D007305:Insecticide Resistance / Q000187:drug effects* / Q000235:genetics*; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects / Q000235:genetics; D010078:Oxazines / Q000494:pharmacology*; D018411:Spodoptera / Q000187:drug effects* / Q000235:genetics*
chemical_list: D007306:Insecticides; D010078:Oxazines; C401104:indoxacarb