title: Lead exposure improves the tolerance of Spodoptera litura (Lepidoptera: Noctuidae) to cypermethrin.
abstract: Many ecological factors such as heavy metals can affect the tolerance of herbivorous insects to chemical insecticide. Spodoptera litura larvae exposed to lead (Pb) (0-100 mg kg(-1) in artificial diet) did not inhibit their growth. After 96 h of Pb (0-100 mg kg(-1)) exposure, topical application and feeding of cypermethrin to S. litura decreased their mortality and increased weight gain. Moreover, the mortality of S. litura treated with 25 and 50 mg kg(-1) of Pb for five generations was significantly lower than control. In addition, Pb accumulation was detected in midgut, fat body, brain and hemolymph, and its highest level was in the midgut. Furthermore, there was a significant negative correlation between Pb accumulation in fat body and mortality after topical application of cypermethrin. After 96 h of Pb exposure, there was increase expression of detoxification enzymes (CYP9A39 and CYP6B47) in midgut and fat body of S. litura. Therefore, the tolerance of S. litura to cypermethrin is increased by Pb exposure at certain concentrations through Pb accumulation in body and the increase of CYP9A39 and CYP6B47 expression.
authors.affiliation: State Key Laboratory of Biological Control and Institute of Entomology, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Jialiang
authors.initials: J
authors.lastname: Zhou
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Shu
authors.forename: Guren
authors.initials: G
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhou
mesh_terms: D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance / Q000187:drug effects*; D004785:Environmental Pollutants / Q000378:metabolism / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007306:Insecticides; D007814:Larva / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D007854:Lead / Q000378:metabolism / Q000494:pharmacology*; D011722:Pyrethrins; D018411:Spodoptera / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D013997:Time Factors
chemical_list: D004785:Environmental Pollutants; D007306:Insecticides; D011722:Pyrethrins; C017160:cypermethrin; D007854:Lead; D003577:Cytochrome P-450 Enzyme System