title: Synergistic insecticidal mode of action between sesquiterpene lactones and a phototoxin, alpha-terthienyl.
abstract: The synergistic insecticidal action of characteristic defensive substances produced by the plant family Asteraceae was investigated under controlled laboratory conditions. Sesquiterpene lactones isolated from Asteraceae that may form, through a Michael addition process, conjugates with glutathione were administered in a meridic diet to a herbivorous insect, Manduca sexta. By administering sesquiterpenes, variable in vivo reduced glutathione levels were observed in the insect larvae. When the Asteraceae-derived photooxidant alpha-terthienyl was co-administered, lipid peroxidation and larval mortality were significantly enhanced in the treated groups of insects with lowered in vivo glutathione levels.
authors.affiliation: University of Ottawa, Department of Biology, Ontario, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Guillet
authors.forename: J
authors.initials: J
authors.lastname: Harmatha
authors.forename: T G
authors.initials: TG
authors.lastname: Waddell
authors.forename: B J
authors.initials: BJ
authors.lastname: Philogène
authors.forename: J T
authors.initials: JT
authors.lastname: Arnason
mesh_terms: D000818:Animals; D019659:Asteraceae; D005978:Glutathione / Q000378:metabolism; D007306:Insecticides / Q000633:toxicity; D007783:Lactones / Q000302:isolation & purification / Q000633:toxicity; D007814:Larva / Q000187:drug effects / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D018402:Manduca / Q000502:physiology*; D010572:Pest Control, Biological; D017319:Photosensitizing Agents / Q000633:toxicity*; D012717:Sesquiterpenes / Q000302:isolation & purification / Q000633:toxicity*; D013876:Thiophenes / Q000633:toxicity*
chemical_list: D007306:Insecticides; D007783:Lactones; D017319:Photosensitizing Agents; D012717:Sesquiterpenes; D013876:Thiophenes; C019101:alpha-terthienyl; D005978:Glutathione