title: Effects of sublethal concentrations of the chitin synthesis inhibitor, hexaflumuron, on the development and hemolymph physiology of the cutworm, Spodoptera litura.
abstract: The effects of sublethal concentrations 0.1, 0.5, and 1.2 µg mL(-1)of the chitin synthesis inhibitor, hexaflumuron, on larval growth and development, the count and proportion of hemocytes, and carbohydrate content (trehalose and glyceride) in hemolymph were investigated in the cutworm, Spodoptera litura (Fabricious) (Lepidoptera: Noctuidae). When 3(rd) instar larvae were subjected to the sublethal concentrations, there were dose-dependent effects on larval weight and length of each instar larvae, percent pupation and the duration of development. Most of the larvae died during the molting process at all concentrations. Few individuals from 0.5 and 1.2 µg mL(-1)concentrations could develop to the 6(th) instar, while the pupae emerging from the 0.1 µg mL(-1)concentrations did not exceed 16% of the number of the initial larvae. In 5(th)instar S. litura, the total number of hemocytes was significantly increased at 24 hours post-treatment, whereas the proliferation of hemocytes was inhibited, plasmatocyte pseudopodia contracted, and granulocyte expanded at 96 hours post-treatment. The increases of plasmatocyte count and the decreases of granulocyte count were dose-dependent. The longer treatment time of the sublethal concentrations increased the content of total carbohydrate and trehalose in hematoplasma, and was dose-dependent in hemocytes. The content of glyceride in hemolymph was significantly higher at 24 hours post-treatment, but gradually returned to normal levels at 96 hours post-treatment as compared with the control. The results suggested that sublethal concentrations of hexaflumuron reduced S. litura larval survival and interfered with hemolymph physiological balances.
authors.affiliation: Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai, China. flower3377@163.com
authors.forename: Qiqi
authors.initials: Q
authors.lastname: Zhu
authors.forename: Yuan
authors.initials: Y
authors.lastname: He
authors.forename: Jing
authors.initials: J
authors.lastname: Yao
authors.forename: Yinzhao
authors.initials: Y
authors.lastname: Liu
authors.forename: Liming
authors.initials: L
authors.lastname: Tao
authors.forename: Qingchun
authors.initials: Q
authors.lastname: Huang
mesh_terms: D000818:Animals; D001549:Benzamides / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006434:Hemocytes / Q000187:drug effects / Q000378:metabolism; D006458:Hemolymph / Q000187:drug effects / Q000378:metabolism*; D007605:Juvenile Hormones / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D010671:Phenylurea Compounds / Q000494:pharmacology*; D011679:Pupa / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018411:Spodoptera / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D005466:Fluorocarbons
chemical_list: D001549:Benzamides; D007605:Juvenile Hormones; D010671:Phenylurea Compounds; C058039:hexafluoron; D005466:Fluorocarbons