Attractiveness of MM-X Traps Baited with Human or Synthetic Odor to Mosquitoes (Diptera: Culicidae) in The Gambia

Abstract

Chemical cues play an important role in the host-seeking behavior of blood-feeding mosquitoes (Diptera: Culicidae). A field study was carried out in The Gambia to investigate the effects of human odor or synthetic odor blends on the attraction of mosquitoes. MM-X traps baited with 16 odor blends to which carbon dioxide (CO 2 ) was added were tested in four sets of experiments. In a second series of experiments, MM-X traps with 14 odor blends without CO 2 were tested. A blend of ammonia and L-lactic acid with or without CO 2 was used as control odor in series 1 and 2, respectively. Centers for Disease Control and Prevention (CDC) traps were placed in a traditional house and an experimental house to monitor mosquito densities during the experiments. The MM-X traps caught a total number of 196,756 mosquitoes, with the most abundant species belonging to the genera Mansonia (70.6%), Anopheles (17.5%), and Culex (11.5%). The most abundant mosquito species caught by the CDC traps (56,290 in total) belonged to the genera Mansonia (59.4%), Anopheles (16.0% An. gambiae s.l. Giles, and 11.3% An. ziemanni Grünberg), and Culex (11.6%). MM-X traps baited with synthetic blends were in many cases more attractive than MM-X traps baited with human odors. Addition of CO 2 to synthetic odors substantially increased the catch of all mosquito species in the MM-X traps. A blend of ammonia + L-lactic acid + CO 2 + 3-methylbutanoic acid was the most attractive odor for most mosquito species. The candidate odor blend shows the potential to enhance trap collections so that traps will provide better surveillance and possible control.Keywords mosquito sampling; odor baits; carbon dioxide; human odor In Africa, major problems are caused by anopheline mosquitoes that act as vectors of human malarias. One of the most important species is Anopheles gambiae s.s. Giles, distinctive for its strong preference for human blood and close association with human habitation. Host seeking and blood feeding of An. gambiae take place during the night. Physical cues, and, © 2007 Entomological Society of America 6 Corresponding author, willem.takken@wur.nl.. Europe PMC Funders GroupAuthor Manuscript J Med Entomol. Author manuscript; available in PMC 2013 November 07. Europe PMC Funders Author ManuscriptsEurope PMC Funders Author Manuscripts more importantly, chemical cues emanating from humans, mediate host-seeking behavior (Takken and Knols 1999). Gillies and Wilkes (1968) reported that CO 2 could attract mosquitoes to hosts at distances of 18-36 m and skin odors at distances of 54-73 m. Human skin odors were demonstrated to account for most of the attractiveness to An. gambiae (Costantini et al. 1996(Costantini et al. , 1998, whereas breath was shown to be only slightly attractive or even repellent , Mukabana et al. 2004. Evidence has accumulated that the variation of the attractiveness between human individuals to An. gambiae is odor mediated (Brady et al. 1997, Costantini et al. 1998, Mukabana 2002, Qiu et al. 2006b).Although hundreds of componen...

Using Nylon Strips to Dispense Mosquito Attractants for Sampling the Malaria Vector <I>Anopheles gambiae</I> s.s.

“…Another problem was that to test an odor-blend consisting of several different constituents, one would need a lot more vials than could possibly be inserted into the MMX trap. This means that even though the MMX is an efÞcient trap for host seeking mosquitoes (Cooperband and Carde 2006, Njiru et al 2006, Qiu et al 2007, Schmied et al 2008, baiting it with synthetic odor blends especially those consisting of many distinct attractants can be difÞcult and may impede adequate airßow through the attractant plume tube. As described later under the subsection ÔTests to compare the nylon strips with other odor dispensing methods,Õ to evaluate the behavioral responses of mosquitoes to our test blend, which consisted of multiple constituents, we initially had to use customized odor dispensing methods so as to allow the required number of vials to be used with the MMX trap, but that unfortunately had the potential of distorting airßow within the attractant plume tube of the trap.…”

Human skin microbiota and their volatiles as odour baits for the malaria mosquito Anopheles gambiae s.s

“…Semi-field and field studies have shown that CO 2 increases trap catches of several species of mosquitoes, including An. gambiae (Costantini et al, 1996;Qiu et al, 2007;Schmied et al, 2008;Jawara et al, 2009), although high concentrations of CO 2 can inhibit the response of mosquitoes to host odours (Lefèvre et al, 2009). Other breath components do not increase the attraction of An.…”

“…Mosquito Magnet-X (MM-X) traps are commonly used in field studies to test attractants (Kline, 2007;Qiu et al, 2007;Jawara et al, 2009;Okumu et al, 2010). The purpose of this study was to examine whether volatiles released by human skin bacteria grown on agar as well as a blend of 10 compounds identified in an earlier study (Verhulst et al, 2009) can be used as odour baits in MM-X traps.…”

Evaluation of ammonia, human sweat, and bovine blood as attractants for the female canyon fly, Fannia conspicua (Diptera: Muscidae), in southern California

“…Ammonia was similarly found to work in synergy with the sweat odor L‐lactic acid to increase capture of Aedes aegypti L., even though ammonia was not attractive when used alone (Geier et al 1999). And the addition of ammonia and L‐lactic acid to traps baited with CO 2 has also been shown to increase the capture of Aedes mosquitoes over traps baited with CO 2 alone (Qiu et al 2007). It is unclear whether ammonia is acting in synergy with CO 2 over some substantial distance to increase the number of F. conspicua attracted to the vicinity of the trap or over a relatively short distance to increase the capture of flies already attracted to the vicinity of the trap by orientation toward the CO 2 source.…”