title: Baseline Insecticide Susceptibility Screening Against Six Active Ingredients for Culex and Aedes (Diptera: Culicidae) Mosquitoes in the United States.
abstract: Mosquitoes may develop resistance to insecticide active ingredients (AI). Thus, mosquitoes should be tested for resistance to confirm efficacy of insecticide-based control, inform management decisions, and protect public and environmental health. Our objectives were to determine a baseline of resistance for six AIs used in mosquito control in the United States to assess how resistance differs between mosquito collection location, AI, and mosquito species (container-ovipositing Aedes and Culex that may oviposit in containers or other sources). Field-collected eggs from 26 mosquito populations of five different species or hybrid species (Aedes albopictus Say, Aedes triseriatus Say, Culex pipiens L., Culex quinquefasciatus Say, Culex pipiens/quinquefasciatus) were obtained from four regions across the United States. Centers for Disease Control and Prevention bottle bioassays were used to determine baseline resistance and susceptibility status for six AIs (bifenthrin, deltamethrin, etofenprox, malathion, permethrin, and phenothrin). World Health Organization guidelines were used to classify mosquitoes as susceptible (98-100% mortality at diagnostic time [DT]), possibly resistant (80-97% mortality at DT), or resistant (< 80% mortality at DT). Aedes spp. mosquitoes were less likely to exhibit resistance, compared with Culex spp. mosquitoes. A high degree of resistance to etofenprox and malathion was observed (4-26-fold greater resistance to these two AIs compared with the other examined AIs). Baseline data on resistance and susceptibility for mosquitoes exposed to commonly used insecticides may help us evaluate resistance trends and highlight the importance of assessing local resistance trends before insecticide-based control measures are implemented.
authors.affiliation: East Carolina University, Department of Health Education and Promotion, Environmental Health Science Program, 3403 Carol Belk Bldg., 300 Curry Court, Greenville, NC 27858 (richardss@ecu.edu; balanayj@ecu.edu; fieldsme91@outlook.com).
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Richards
authors.affiliation: East Carolina University, Department of Health Education and Promotion, Environmental Health Science Program, 3403 Carol Belk Bldg., 300 Curry Court, Greenville, NC 27858 (richardss@ecu.edu; balanayj@ecu.edu; fieldsme91@outlook.com).
authors.forename: Jo Anne G
authors.initials: JAG
authors.lastname: Balanay
authors.affiliation: East Carolina University, Department of Health Education and Promotion, Environmental Health Science Program, 3403 Carol Belk Bldg., 300 Curry Court, Greenville, NC 27858 (richardss@ecu.edu; balanayj@ecu.edu; fieldsme91@outlook.com).
authors.forename: Melinda
authors.initials: M
authors.lastname: Fields
authors.affiliation: Bayer Crop Science, Environmental Science/Vector Control and Pest Management, 2 T.W. Alexander Dr., Research Triangle Park, NC 27709 (kurt.vandock@bayer.com).
authors.forename: Kurt
authors.initials: K
authors.lastname: Vandock
mesh_terms: D000330:Aedes / Q000187:drug effects*; D000818:Animals; D003465:Culex / Q000187:drug effects*; D005260:Female; D005843:Geography; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D013045:Species Specificity; D014481:United States
chemical_list: D007306:Insecticides
keywords: bottle bioassay; insecticide resistance; mosquito; mosquito control