title: Life-stage variation in insecticide resistance of the western flower thrips (Thysanoptera: Thripidae).
abstract: The life-stage variations in insecticide resistance of western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), to selective insecticides (acrinathrin, formetanate, and methiocarb) were studied using resistant laboratory strains. In each strain, the second-instar larva was less susceptible to the insecticides tested than the adults. The lower the resistance level of the adults, the higher the difference between larva and adult susceptibility: 32-fold to methiocarb, 15.4-fold to formetanate, and 180-fold to acrinathrin in the reference strain. In laboratory-selected resistant strains, these differences were much lower: 5.8-fold to methiocarb, 4.8-fold to formetanate, and 2.0-fold to acrinathrin. In selected strains, higher resistance levels for each insecticide were found, both for larvae and adults, compared with the reference strain. These results show that after insecticide resistance selection in adults, the resistance is carried over to the larvae, but at lower levels.
authors.affiliation: Departamento de Producción Vegetal, ETSIA, Universidad Politécnica de Cartagena, Paseo Alfonso XIII, 48, 30203, Cartagena, Spain. josefina.contreras@upct.es
authors.forename: J
authors.initials: J
authors.lastname: Contreras
authors.forename: P J
authors.initials: PJ
authors.lastname: Espinosa
authors.forename: V
authors.initials: V
authors.lastname: Quinto
authors.forename: J
authors.initials: J
authors.lastname: Abellán
authors.forename: C
authors.initials: C
authors.lastname: Grávalos
authors.forename: E
authors.initials: E
authors.lastname: Fernández
authors.forename: P
authors.initials: P
authors.lastname: Bielza
mesh_terms: D000818:Animals; D002219:Carbamates / Q000494:pharmacology; D007313:Insecta / Q000187:drug effects*; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva; D007928:Lethal Dose 50; D008714:Methiocarb / Q000494:pharmacology; D011722:Pyrethrins / Q000494:pharmacology; D005466:Fluorocarbons
chemical_list: D002219:Carbamates; D007306:Insecticides; D008714:Methiocarb; D011722:Pyrethrins; C100163:formetanate; C119568:acrinathrin; D005466:Fluorocarbons