Submitted to: Journal of Vector Ecology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/12/2003
Publication Date: 12/1/2004
Citation: Allan, S.A., Kline, D.L. 2004. Evaluation of various attributes of gravid female traps for collection of culex in florida. Journal of Vector Ecology. 29(2):285-294. Interpretive Summary: Culex mosquitoes are the most important vectors of West Nile virus and St. Louis encephalitis in the United States. Trapping is critical in the surveillance of both vector abundance and disease presence and often guides subsequent control efforts. Conventional light traps, however, are of limited value for trapping these species and traps that target egg-laying (gravid) females are generally preferred for trapping these mosquitoes. In this study, conducted by USDA scientists at the Center for Medical, Veterinary and Agricultural Entomology in Gainesville (Florida) CMAVE, various parameters of gravid female traps were examined to determine the most effective for trapping. Different models of commercial traps differed in their efficacy for trapping Culex mosquitoes. Size and color of pan were also important factors influencing trap efficacy with greater collections in pans with larger and darker pans. This information provides the basis for development of effective standardized trapping strategies for Culex mosquitoes.
Technical Abstract: Gravid female traps are used for surveillance of populations of Culex spp. and arboviruses such as West Nile virus. Field trials evaluating various attributes of gravid female traps for collection of gravid Culex were conducted in rural habitats in Alachua and Marion Counties, Florida. Screened cage tests in the field were also used to compare trap models. Three trap models were evaluated; two based on the original Reiter design (Gravid CDC traps A and B) and one based on the revised Reiter design (gravid box trap). Trap model significantly affected collection of Culex quinquefasciatus and Culex nigripalpus; the greatest numbers were collected by the CDC gravid trap A and CDC gravid trap B traps compared to the gravid box traps. There were no statistically significant differences between the collections with CDC gravid trap A and B traps. These patterns were similar at both sites and between early and late summer collections in Marion Co. In trials conducted in screened field cages with gravid Cx. quinquefasciatus, significantly more mosquitoes were collected in the CDC gravid trap A and B than in box gravid traps. Size of pan associated with the gravid traps was important and traps with larger pans collected more mosquitoes. Pan color was also important in efficacy of traps and traps with darker pans (black, green) collected more mosquitoes than traps with lighter pans (tan, white). The percentages of gravid mosquitoes in trap collections of Culex females ranged from 54.0% to 89.6% with no clear differences between model of trap, size of pan or pan color. Various attributes of gravid female traps impact efficacy of gravid female traps for Culex spp. and these should be considered in trapping programs.