title: Plant Essential Oils Synergize and Antagonize Toxicity of Different Conventional Insecticides against Myzus persicae (Hemiptera: Aphididae).
abstract: Plant-derived products can play an important role in pest management programs. Essential oils from Lavandula angustifolia (lavender) and Thymus vulgaris (thyme) and their main constituents, linalool and thymol, respectively, were evaluated for insecticidal activity and synergistic action in combination with insecticides against green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae). The essential oils and their main constituents exerted similar insecticidal activity when aphids were exposed by direct sprays, but were non-toxic by exposure to treated leaf discs. In synergism experiments, the toxicity of imidacloprid was synergized 16- to 20-fold by L. angustifolia and T. vulgaris essential oils, but far less synergism occurred with linalool and thymol, indicating that secondary constituents of the oils were probably responsible for the observed synergism. In contrast to results with imidacloprid, the insecticidal activity of spirotetramat was antagonized by L. angustifolia and T. vulgaris essential oils, and linalool and thymol. Our results demonstrate the potential of plant essential oils as synergists of insecticides, but show that antagonistic action against certain insecticides may occur.
authors.affiliation: Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, B2N 5E3 Canada.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Faraone
authors.affiliation: Department of Biology, Acadia University, Wolfville, Nova Scotia, B4P 2R6 Canada.
authors.forename: N Kirk
authors.initials: NK
authors.lastname: Hillier
authors.affiliation: Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, B2N 5E3 Canada.
authors.forename: G Christopher
authors.initials: GC
authors.lastname: Cutler
mesh_terms: D000080462:Acyclic Monoterpenes; D000818:Animals; D001042:Aphids / Q000187:drug effects / Q000502:physiology*; D007306:Insecticides / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D027523:Lavandula / Q000737:chemistry; D039821:Monoterpenes / Q000494:pharmacology; D009822:Oils, Volatile / Q000302:isolation & purification / Q000494:pharmacology*; D010938:Plant Oils / Q000494:pharmacology*; D013943:Thymol / Q000494:pharmacology
chemical_list: D000080462:Acyclic Monoterpenes; D007306:Insecticides; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; D013943:Thymol; C018584:linalool