title: The role of octopamine receptor agonists in the synergistic toxicity of certain insect growth regulators (IGRs) in controlling Dengue vector Aedes aegypti (Diptera: Culicidae) mosquito.
abstract: The synergistic action of octopamine receptor agonists (OR agonists) on many insecticide classes (e.g., organophosphorus, pyrethroids, and neonicotinoids) on Aedes aegypti L. has been reported recently. An investigation of OR agonist's effect on insect growth regulators (IGRs) was undertaken to provide a better understanding of the mechanism of action. Based on the IGR bioassay, pyriproxyfen was the most potent IGR insecticide tested (EC50=0.0019ng/ml). However, the lethal toxicity results indicate that diafenthiuron was the most potent insecticide (LC50=56ng/cm(2)) on A. aegypti adults after 24h of exposure. The same trend was true after 48 and 72h of exposure. Further, the synergistic effects of OR agonists plus amitraz (AMZ) or chlordimeform (CDM) was significant on adults. Among the tested synergists, AMZ increased the potency of the selected IGRs on adults the greatest. As results, OR agonists were largely synergistic with the selected IGRs. OR agonists enhanced the lethal toxicity of IGRs, which is a valuable new tool in the field of A. aegypti control. However, further field experiments need to be done to understand the unique potential role of OR agonists and their synergistic action on IGRs.
authors.affiliation: Plant Protection Department, Faculty of Agriculture, Assiut University, Assiut 71526, Egypt; Center for Health and the Environment, One Shields Avenue, University of California, Davis, CA 95616, USA.
authors.forename: Mohamed Ahmed Ibrahim
authors.initials: MA
authors.lastname: Ahmed
authors.affiliation: Center for Health and the Environment, One Shields Avenue, University of California, Davis, CA 95616, USA; Department of Environmental Toxicology, University of California, One Shields Avenue, Davis, CA 95616, USA. Electronic address: cfvogel@ucdavis.edu.
authors.forename: Christoph Franz Adam
authors.initials: CF
authors.lastname: Vogel
mesh_terms: D000330:Aedes / Q000187:drug effects*; D000818:Animals; D001681:Biological Assay; D002742:Chlorphenamidine / Q000633:toxicity; D003715:Dengue / Q000517:prevention & control*; D004357:Drug Synergism; D006801:Humans; D007303:Insect Vectors / Q000187:drug effects*; D007306:Insecticides / Q000145:classification / Q000633:toxicity; D007605:Juvenile Hormones / Q000378:metabolism / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D009032:Mosquito Control / Q000379:methods; D010574:Pesticide Synergists / Q000633:toxicity; D017982:Receptors, Biogenic Amine / Q000819:agonists* / Q000187:drug effects; D014052:Toluidines / Q000633:toxicity
chemical_list: D007306:Insecticides; D007605:Juvenile Hormones; D010574:Pesticide Synergists; D017982:Receptors, Biogenic Amine; D014052:Toluidines; C027604:norsynephrine receptor; C014983:amitraz; D002742:Chlorphenamidine
keywords: Aedes aegypti; IGRs; Insecticide resistance; Mosquito control; Octopamine receptor agonists; Synergistic ratio