title: Suboptimal Larval Habitats Modulate Oviposition of the Malaria Vector Mosquito Anopheles coluzzii.
abstract: Selection of oviposition sites by gravid females is a critical behavioral step in the reproductive cycle of Anopheles coluzzii, which is one of the principal Afrotropical malaria vector mosquitoes. Several studies suggest this decision is mediated by semiochemicals associated with potential oviposition sites. To better understand the chemosensory basis of this behavior and identify compounds that can modulate oviposition, we examined the generally held hypothesis that suboptimal larval habitats give rise to semiochemicals that negatively influence the oviposition preference of gravid females. Dual-choice bioassays indicated that oviposition sites conditioned in this manner do indeed foster significant and concentration dependent aversive effects on the oviposition site selection of gravid females. Headspace analyses derived from aversive habitats consistently noted the presence of dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and 6-methyl-5-hepten-2-one (sulcatone) each of which unitarily affected An. coluzzii oviposition preference. Electrophysiological assays across the antennae, maxillary palp, and labellum of gravid An. coluzzii revealed differential responses to these semiochemicals. Taken together, these findings validate the hypothesis in question and suggest that suboptimal environments for An. coluzzii larval development results in the release of DMDS, DMTS and sulcatone that impact the response valence of gravid females.
authors.affiliation: Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America.
authors.forename: Eunho
authors.initials: E
authors.lastname: Suh
authors.affiliation: Department of Entomology, University of California, Riverside, California, United States of America.
authors.forename: Dong-Hwan
authors.initials: DH
authors.lastname: Choe
authors.affiliation: Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Saveer
authors.affiliation: Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America.|Department of Pharmacology, Vanderbilt Brain Institute, Program in Developmental Biology, and Institutes of Chemical Biology and Global Health, Vanderbilt University Medical Center, Tennessee, United States of America.
authors.forename: Laurence J
authors.initials: LJ
authors.lastname: Zwiebel
mesh_terms: D000818:Animals; D000852:Anopheles / Q000502:physiology*; D004220:Disulfides / Q000494:pharmacology; D017753:Ecosystem; D005260:Female; D007303:Insect Vectors / Q000502:physiology*; D007659:Ketones / Q000494:pharmacology; D007814:Larva; D008288:Malaria; D010058:Oviposition / Q000187:drug effects / Q000502:physiology*; D013440:Sulfides / Q000494:pharmacology
chemical_list: D004220:Disulfides; D007659:Ketones; D013440:Sulfides; C054170:dimethyl trisulfide; C021181:dimethyl disulfide; C029750:methylheptenone