Trapping mosquitoes using milk products as odour baits in western Kenya

BACKGROUND: Ample evidence has shown that blood seeking mosquitoes locate their hosts by following odours produced by the hosts. Odour baited traps would therefore, provide a solution in controlling diseases spread by mosquitoes. Comparative studies were undertaken to determine the relative efficacies of two odour baits i.e. Limburger cheese and African traditional milk cream in trapping mosquitoes in the field in western Kenya. METHOD: Comparative efficacy studies were carried out in the field using Latin square experimental designs. In the first study, a counterflow geometry (CFG) trap (MM-x model; American Biophysics Corp., USA.) baited with Limburger cheese, man landing catches (MLC), Centres for Disease Control (CDC) light trap and an entry trap were compared. In the second study, three CFG traps baited with either Limburger cheese, African traditional milk cream or with no bait were compared and in the third study four CDC traps baited with either Limburger cheese, African traditional milk cream, light or with no bait were compared. Parameters like species, catch size, abdominal status, parity status and size of the collected mosquitoes were compared. RESULTS: A total of 1,806 mosquitoes were collected (60% An. gambiae s.l and 25% An.funestus, culicines 15%). There was no significant difference in the number of An. funestus trapped by the CFG trap baited with Limburger cheese from those trapped by the MLC (P = 0.351). The Limburger cheese baited CFG trap collected significantly more gravid An. funestus than the MLC (P = 0.022). Furthermore, when the CFG trap baited with Limburger cheese and the CFG trap baited with milk cream were compared, there was no significant difference in the number of An. funestus collected (P = 0.573). The same trend was observed in the comparison of Limburger cheese baited CDC trap and milk cream baited CDC trap. CONCLUSIONS: Limburger cheese and African traditional milk cream have a potential as effective odour baits for sampling/surveillance and as oviposition attractants for the malaria vector, Anopheles funestus.