A push-pull system to reduce house entry of malaria mosquitoes

Abstract

BackgroundMosquitoes are the dominant vectors of pathogens that cause infectious diseases such as malaria, dengue, yellow fever and filariasis. Current vector control strategies often rely on the use of pyrethroids against which mosquitoes are increasingly developing resistance. Here, a push-pull system is presented, that operates by the simultaneous use of repellent and attractive volatile odorants.Method/ResultsExperiments were carried out in a semi-field set-up: a traditional house which was constructed inside a screenhouse. The release of different repellent compounds, para-menthane-3,8-diol (PMD), catnip oil e.o. and delta-undecalactone, from the four corners of the house resulted in significant reductions of 45% to 81.5% in house entry of host-seeking malaria mosquitoes. The highest reductions in house entry (up to 95.5%), were achieved by simultaneously repelling mosquitoes from the house (push) and removing them from the experimental set-up using attractant-baited traps (pull).ConclusionsThe outcome of this study suggests that a push-pull system based on attractive and repellent volatiles may successfully be employed to target mosquito vectors of human disease. Reductions in house entry of malaria vectors, of the magnitude that was achieved in these experiments, would likely affect malaria transmission. The repellents used are non-toxic and can be used safely in a human environment. Delta-undecalactone is a novel repellent that showed higher effectiveness than the established repellent PMD. These results encourage further development of the system for practical implementation in the field.

Impact of odour-baited mosquito traps for malaria control : design and evaluation of a trial using solar-powered mosquito trapping systems in western Kenya

“…Studies to characterise the components of human odour which are attractive to hostseeking Anopheles gambiae s.s. have led to the identification of a large number of compounds (Mukabana et al, 2012b;Okumu et al, 2010b;Verhulst et al, 2011b) which, at appropriate concentrations, can be combined to create synthetic mosquito lures that mimic a human host (Menger et al, 2014b;Okumu et al, 2010b). These lures can remain attractive to mosquitoes even after a year of use .…”

“…Synthetic lures can be placed in counter flow trapping systems and used to lure and capture host-seeking mosquitoes both inside and outside houses Jawara et al, 2009;Matowo et al, 2013). By capturing mosquitoes outdoors, rates of mosquito house entry can be lowered by between 33% and 80% under semi-field conditions Menger et al, 2014b) and by 50% in the field . It is anticipated that above a certain threshold level of trap coverage, traps could be used to effectively reduce Anopheles gambiae s.l.…”

“…The traps are baited with a blend of five organic attractants that mimic a human odour and lure mosquitoes towards the trap (Menger et al, 2014b). The blend of five chemicals is supplemented with a carbon dioxide mimic (Turner et al, 2011) in order to increase the attraction of malaria vectors to the trap.…”

“…Sampling of mosquitoes at houses is performed using Mosquito Magnet-X ® traps (American Biophysics corporation, North Kingstown, RI), baited with the same blend of five chemicals that are used for the intervention (Menger et al, 2014b) and carbon dioxide produced by yeast and molasses fermentation . For each round of sampling 80 households are randomly selected with replacement from the active database maintained by the HDSS.…”

A multidisciplinary approach to study virulence of the entomopathogenic fungus Beauveria bassiana towards malaria mosquitoes

“…Combining the use of EPF with current insecticides could provide a valuable addition since EPF have different modes of action, which could reduce even more the risks of developing resistance of mosquitoes against EPF. Besides using EPF with current control tools, other methods also have to be considered such as modification of the environment (Imbahale et al, 2012;Kirby et al, 2008), genetic modification of mosquitoes (Lofgren et al, 1974), odour baiting traps systems (Menger et al, 2014), and larval control with other biological control agents (Fillinger and Lindsay, 2006;Kusumawathie et al, 2008). By using several methods in an IVM system approach, long-term sustainability of malaria vector control can be achieved.…”