title: Life stage-dependent susceptibility of Aphytis melinus DeBach (Hymenoptera: Aphelinidae) to two pesticides commonly used in citrus orchards.
abstract: The assessment of pesticides compatibility with natural enemies is recommended before including agrochemicals in integrated and organic pest management schemes. The lethal and sublethal effects of a mineral oil and a juvenile hormone mimic (pyriproxyfen), on adults and larvae of Aphytis melinus, a key ectoparasitoid of armored scale insect pests of citrus, such as Aonidiella aurantii, were evaluated. Mineral oil caused very high mortality on the adults, while a lower acute toxicity was recorded on young instars. No significant effects on their reproduction capacity and on the sex-ratio of the progeny were observed. Pyriproxyfen had neither lethal nor sublethal effects (in terms of survived female fertility) on A. melinus adults. However, parasitoid larvae exposed to this insecticide suffered strong acute toxicity and fertility reduction (progeny number and proportion of female progeny). When adults were offered the choice to parasitize treated and untreated scales they significantly preferred the control ones, and when they were exposed to only treated scaled the parasitism rate was significantly lower only with mineral oil-treated hosts. The significant differences in the susceptibility of the two parasitoid instars highlight the importance of including this aspect in pesticide risk assessment procedures and in the choice of the pesticide and of the treatment timing in the field. Overall, the results indicate potential for integrating A. melinus, both naturally present and artificially released, and these insecticides only by appropriate timing of insecticide spraying and parasitoid releases.
authors.affiliation: University of Catania, Dipartimento di Agricoltura, Alimentazione e Ambiente, via Santa Sofia 100, 95123 Catania, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Biondi
authors.affiliation: University "Mediterranea" of Reggio Calabria, Dipartimento di AGRARIA, Feo di Vito, 89122 Reggio Calabria, Italy.
authors.forename: Orlando
authors.initials: O
authors.lastname: Campolo
authors.affiliation: French National Institute for Agricultural Research (INRA), Institut Sophia Agrobiotech, 400 Route des Chappes, 06903 Sophia-Antipolis, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Desneux
authors.affiliation: University of Catania, Dipartimento di Agricoltura, Alimentazione e Ambiente, via Santa Sofia 100, 95123 Catania, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Siscaro
authors.affiliation: University "Mediterranea" of Reggio Calabria, Dipartimento di AGRARIA, Feo di Vito, 89122 Reggio Calabria, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Palmeri
authors.affiliation: University of Catania, Dipartimento di Agricoltura, Alimentazione e Ambiente, via Santa Sofia 100, 95123 Catania, Italy. Electronic address: lzappala@unict.it.
authors.forename: Lucia
authors.initials: L
authors.lastname: Zappalà
mesh_terms: D000818:Animals; D002957:Citrus; D005260:Female; D006430:Hemiptera / Q000187:drug effects; D006927:Hymenoptera / Q000187:drug effects*; D007306:Insecticides / Q000494:pharmacology*; D007605:Juvenile Hormones; D007814:Larva / Q000187:drug effects; D010571:Pest Control; D011725:Pyridines / Q000009:adverse effects; D012744:Sex Ratio
chemical_list: D007306:Insecticides; D007605:Juvenile Hormones; D011725:Pyridines; C055613:pyriproxyfen
keywords: Ecotoxicology; Mineral oil; Parasitoid; Pyriproxyfen; Scale insects; Sublethal effects