Evaluation of two counterflow traps for testing behaviour-mediating compounds for the malaria vector Anopheles gambiae s.s. under semi-field conditions in Tanzania
Center of Ecology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090 Vienna, Austria; Entomology Unit, Ifakara Health Research and Development Center, Ifakara, Tanzania; Laboratory of Entomology, Wageningen University and Research Center, P.O. Box 8031, 6700 EH Wageningen, Netherlands; School of Biological and Biomedical Sciences, South Road, Durham, DH1 3LE, United Kingdom
Background. Evaluation of mosquito responses towards different trap-bait combinations in field trials is a time-consuming process that can be shortened by experiments in contained semi-field systems. Possible use of the BG Sentinel (BGS) trap to sample Anopheles gambiae s.s. was evaluated. The efficiency of this trap was compared with that of the Mosquito Magnet-X (MM-X) trap, when baited with foot odour alone or combinations of foot odour with carbon dioxide (CO2) or lemongrass as behaviour-modifying cues. Methods. Female An. gambiae s.s. were released in an experimental flight arena that was placed in a semi-field system and left overnight. Catch rates for the MM-X and BGS traps were recorded. Data were analysed by fitting a generalized linear model to the (n+1) transformed catches. Results. Both types of traps successfully captured mosquitoes with all odour cues used. When the BGS trap was tested against the MM-X trap in a choice assay with foot odour as bait, the BGS trap caught about three times as many mosquitoes as the MM-X trap (P = 0.002). Adding CO 2(500 ml/min) to foot odour increased the number of mosquitoes caught by 268% for the MM-X (P < 0.001) and 34% (P = 0.051) for the BGS trap, compared to foot odour alone. When lemongrass leaves were added to foot odour, mosquito catches were reduced by 39% (BGS, P < 0.001) and 38% (MM-X, P = 0.353), respectively. Conclusion. The BGS trap shows high potential for field trials due to its simple construction and high catch rate when baited with human foot odour only. However, for rapid screening of different baits in a contained semi-field system, the superior discriminatory power of the MM-X trap is advantageous. © 2008 Schmied et al; licensee BioMed Central Ltd.
carbon dioxide; carbon dioxide; chemotactic factor; Anopheles gambiae; article; controlled study; Cymbopogon citratus; disease carrier; female; malaria; nonhuman; odor; Tanzania; animal; animal behavior; comparative study; drug effect; human; mosquito; Animals; Anopheles gambiae; Behavior, Animal; Carbon Dioxide; Chemotactic Factors; Female; Humans; Mosquito Control; Odors; Tanzania