title: UV light and urban pollution: bad cocktail for mosquitoes?
abstract: Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species-ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis-Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on mosquitoes, including tolerance to three insecticides (imidacloprid, propoxur and temephos), cell damage and response to oxidative stress. Taken together, our results suggest that UV and pollution, individually or in combination, are abiotic parameters that can affect the physiology and insecticide tolerance of mosquitoes; but the complexity of their direct effect and of their interaction will require further investigation to know in which condition they can affect the efficacy of insecticide-based vector control strategies in the field.
authors.affiliation: Laboratoire d'Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09, France; Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456, USA. Electronic address: guillaume.tetreau@gmail.com.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Tetreau
authors.affiliation: Laboratoire d'Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09, France.
authors.forename: Alexia
authors.initials: A
authors.lastname: Chandor-Proust
authors.affiliation: Laboratoire d'Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Faucon
authors.affiliation: Laboratoire d'Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Stalinski
authors.affiliation: Laboratoire d'Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09, France.
authors.forename: Idir
authors.initials: I
authors.lastname: Akhouayri
authors.affiliation: Laboratoire d'Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09, France.
authors.forename: Sophie M
authors.initials: SM
authors.lastname: Prud'homme
authors.affiliation: Laboratoire d'Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09, France.
authors.forename: Myriam
authors.initials: M
authors.lastname: Régent-Kloeckner
authors.affiliation: Laboratoire d'Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Raveton
authors.affiliation: Laboratoire d'Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Reynaud
mesh_terms: D000330:Aedes / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D000818:Animals; D004785:Environmental Pollutants / Q000494:pharmacology*; D007305:Insecticide Resistance / Q000187:drug effects / Q000528:radiation effects; D007814:Larva / Q000187:drug effects / Q000528:radiation effects; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014466:Ultraviolet Rays; D014505:Urban Population
chemical_list: D004785:Environmental Pollutants; D011084:Polycyclic Aromatic Hydrocarbons; D017382:Reactive Oxygen Species
keywords: Aedes aegypti; Bioassay; Enzymatic activities; Insecticides; Polycyclic aromatic hydrocarbon; Ultraviolet