title: The insect growth regulator insecticide cyromazine causes earlier emergence in Drosophila melanogaster.
abstract: The insecticide cyromazine, classified as an insect growth regulator, inhibits the growth and development of Diptera. The precise mode of cyromazine action remains unknown. We investigated mortality and developmental time effects after exposing first instar Drosophila melanogaster larvae to cyromazine for 8-h intervals. Significant increases in mortality were only observed for cyromazine exposure within the first 16 h of the first instar stage, suggesting that cyromazine accumulates in the larvae over time and that there is a delay between cyromazine exposure and effect. We observed that exposure to cyromazine during the early first instar stage resulted in earlier eclosion of adults when compared to cyromazine exposure at later first instar stages. The presence of 20-hydroxyecdysone during cyromazine exposure significantly reduced the lethal effect of cyromazine. We raise the possibility that the mode of cyromazine action is related to the development hormone, 20-hydroxyecdysone.
authors.affiliation: Centre for Environmental Stress and Adaptation Research (CESAR), Bio21 Molecular Science and Biotechnology Institute, Department of Genetics, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Angela P
authors.initials: AP
authors.lastname: Van de Wouw
authors.forename: Philip
authors.initials: P
authors.lastname: Batterham
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Daborn
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004331:Drosophila melanogaster / Q000254:growth & development*; D004441:Ecdysterone / Q000378:metabolism; D007306:Insecticides / Q000378:metabolism / Q000633:toxicity*; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D008675:Metamorphosis, Biological / Q000187:drug effects*; D009026:Mortality; D013997:Time Factors; D014227:Triazines / Q000378:metabolism / Q000633:toxicity*
chemical_list: D007306:Insecticides; D014227:Triazines; D004441:Ecdysterone; C028704:cyromazine