Landing responses of Anopheles gambiae elicited by oxocarboxylic acids

Abstract

Abstract. A wind tunnel bioassay and video system were used to observe Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) landing on glass cylinders, heated to human skin temperature (34 C) and treated with aqueous solutions of oxocarboxylic acids. Six of nine compounds tested: 2-oxobutanoic, 2-oxo-3-methylbutanoic, 2-oxopentanoic, 2-oxo-3-methylpentanoic, 2-oxo-4-methylpentanoic and 2-oxohexanoic elicited significant landing responses in comparison to a water control. Landing responses appeared to be restricted to C4±C6, 2-oxocarboxylic acids. A solution of 1 mg=mL of 2-oxopentanoic acid elicited the highest level of response that was temperature dependent: significant numbers of landings occurred only within AE2 C of human skin temperature. Chemical analysis by linked gas-liquid chromatography=mass spectrometry of methyl-oxime, trimethylsilyl derivatized samples of human sweat extracts revealed the presence of 2-oxopropanoic (pyruvic) acid and three behaviourally active, branched chain acids: 2-oxo-3-methylbutanoic, 2-oxo-3-methylpentanoic and 2-oxo-4-methylpentanoic.

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

“…gambiae s.s. in the laboratory (Bernier et al 2000, Meijerink et al 2000, Costantini et al 2001, Healy et al 2002, Qiu 2005, Smallegange et al 2005, Qiu et al 2006a. Chemicals used in our experiments, their purity, producer as well as the bioactivity reported for An.…”

“…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 components have been identified from human odors, only a few compounds were tested singly and proven to be attractive to mosquitoes (Bernier et al 2000(Bernier et al , 2002Healy et al 2002). Ammonia, a compound present in incubated human sweat, was repeatedly reported to be attractive in an olfactometer (Geier et al 1999, Smallegange et al 2005.…”

“…The latter compound was detected in the volatiles of Limburger cheese and human sweat, and these volatiles were found to be attractive to female An. gambiae s.s. (Cork and Park 1996, Meijerink et al 2000, Healy et al 2002. Olfactometry experiments showed that certain concentrations of 3-methylbutanoic acid increased the attractiveness of ammonia + L-lactic acid (Qiu 2005).…”

Arthropod semiochemicals: mosquitoes, midges and sealice

“…Mordue Luntz, unpublished work; [6,7,[12][13][14]), all of which are giving rise to possibilities of push-pull strategies using odour-baited traps and repellents.…”

Microorganism-mediated behaviour of malaria mosquitoes

“…gambiae through odorant receptors (Carey et al, 2010). Some VOCs can be detected from a distance as far as 70 meters from the source Carey & Carlson, 2011;Chaisson & Hallem, 2012), while others may be more important in initiating a landing response on the host (Healy & Copland, 2000;Healy et al, 2002).…”