Abstract
Odour baited traps have potential use in population surveillance of insect vectors of disease, and in some cases for vector population reduction. Established attractants for human host-seeking mosquitoes include a combination of CO2 with L-lactic acid and ammonia, on top of which additional candidate compounds are being tested. In this field study in rural Gambia, using Latin square experiments with thorough randomization and replication, we tested nine different leading candidate combinations of chemical odorants for attractiveness to wild mosquitoes including anthropophilic malaria vectors, using modified Mosquito Magnet-X (MM-X) counterflow traps outside experimental huts containing male human sleepers. Highest catches of female mosquitoes, particularly of An. gambiae s.l. and Mansonia species, were obtained by incorporation of tetradecanoic acid. As additional carboxylic acids did not increase the trap catches further, this ‘reference blend’ (tetradecanoic acid with L-lactic acid, ammonia and CO2) was used in subsequent experiments. MM-X traps with this blend caught similar numbers of An. gambiae s.l. and slightly more Mansonia and Culex mosquitoes than a standard CDC light trap, and these numbers were not significantly affected by the presence or absence of human sleepers in the huts. Experiments with CO2 produced from overnight yeast cultures showed that this organic source was effective in enabling trap attractiveness for all mosquito species, although at a slightly lower efficiency than obtained with use of CO2 gas cylinders. Although further studies are needed to discover additional chemicals that increase attractiveness, as well as to optimise trap design and CO2 source for broader practical use, the odour-baited traps described here are safe and effective for sampling host-seeking mosquitoes outdoors and can be incorporated into studies of malaria vector ecology.
Highlights
Surveillance of malaria vector mosquitoes is vital for understanding transmission ecology and monitoring changes that occur in response to interventions
Of the abundant compounds in human sweat, ammonia and Llactic acid have been shown to be attractive to female mosquitoes of several species including the principal African malaria vector Anopheles gambiae sensu stricto, and other chemicals including carboxylic acids have been tested for effects on top of these basic compounds combined with CO2 in an attempt to attract this anthropophilic species [9]
Consistent with the laboratory studies, we show that tetradecanoic acid with ammonia and L-lactic acid is the most attractive blend delivered with CO2, and none of the additional carboxylic acids tested in more complex blends enhanced the attractiveness
Summary
Surveillance of malaria vector mosquitoes is vital for understanding transmission ecology and monitoring changes that occur in response to interventions. Of the abundant compounds in human sweat, ammonia and Llactic acid have been shown to be attractive to female mosquitoes of several species including the principal African malaria vector Anopheles gambiae sensu stricto , and other chemicals including carboxylic acids have been tested for effects on top of these basic compounds combined with CO2 in an attempt to attract this anthropophilic species [9]. Tetradecanoic acid with ammonia and L-lactic acid was shown to be robustly attractive when delivered within Mosquito Magnet-X (MM-X) counterflow traps in laboratory experiments, as such traps are physically designed for outdoor field use and enable discrimination between the attractiveness of different odour baits [11]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
