Utilising techniques normally applied to automotive engines, sprays and other mainstream mechanical devices, researchers at Warwick’s School of Engineering are working to understand the behaviour of mosquitoes. Their ground-breaking research is providing hitherto unavailable data that will create practical solutions and development of improved approaches to fight malaria in Africa and around the world.

Despite considerable success in combating malaria including the use of insecticide treated bednets, new tools and interventions are still required to combat mosquitoes that evade current strategies or are becoming insecticide resistant. Researchers have previously relied on recording the end-point (landing location) of mosquitoes, which hasn’t given an overall picture of their behaviour. The new innovative research investigates natural mosquito behaviours and the use of bednets to control mosquitoes and reduce cases of malaria.

The €12M research project called AvecNet (www.avecnet.eu), is funded by an FP7 grant and brings together a multidisciplinary team of European and African experts including biologists, engineers, epidemiologists, social scientists. The optical engineers at Warwick, David Towers, Natalia Angarita and Catherine Towers, are working with entomologists at Liverpool School of Tropical Medicine (LSTM), Philip McCall and Josie Parker, to quantify the use of bednets in lowering transmission rates of malaria and the effect of insecticide treatment on mosquito behaviour. Imaging systems have been developed at Warwick and transferred to a laboratory at LSTM and hence to a field site in Tanzania, using nets with/without insecticide and with/without ‘human bait’ (a person in a sleeping position under the net).

The field site, by a swamp in Tanzania, is an ideal location giving a stable population of mosquitoes for entomologists and a mixed population of mosquitoes, some resistant to insecticide, others not. This is particularly important, as insecticide resistance is of particular concern in the bed net community.

The researchers have constructed a hut at the field site which mimics the typical house and sleeping arrangements for the local population. Experiments are conducted at night when the residents are at greatest risk of being bitten by anopheles gambiae mosquitoes: the species responsible for transmission of the malaria parasite which is the most dangerous to humans. The mosquitoes are attracted by heat, odour and carbon dioxide exhaled by people sleeping.

Using a modified back lighting technique these millimetre scale insects can be imaged throughout a 2.0 × 2.4 × 1.0 metre volume by using illumination in the near infra-red – a ‘mosquito blind’ wavelength so as not to alter their natural behaviour. Two cameras are positioned to capture images at a rate of 50 per second. Every hour-long dataset comprises of 360,000 images, each taken at 4 million pixels, or 1.4 TB in total size.

Software capable of analysing such a large number of high resolution images was not available at the beginning of the project and has been written especially for these experiments – over 50TB of data has been processed to date.

Professor David Towers said: “There is a lot of interest in the analysis of so-called ‘big data’ – here we have the added complexity of capturing information from the field with everything powered from petrol fuelled generators and we need very robust algorithms to be tolerant of the natural variability in behaviour exhibited by wild mosquitoes”.

The current grant is nearing its conclusion and some initial findings are published at www.nature.com/srep, with images from the project selected for the front page article in the Financial Times Special Report to coincide with World Malaria Day in April 2015. The researchers are pleased to have received a further £0.9M support from the Medical Research Council (MRC) for their next project. The new experiments will use eight cameras, collecting up to 10TB of data per hour, to map not just the sleeping area, but the hut as a whole. This will enable the team to fully map the behaviour of the mosquitoes as they approach their targets. Early indications show that the mosquitoes don’t realise a net is treated before they touch it and the future research will build on these findings.

A MRC Confidence in Concept grant has also been awarded to build the innovative new net which was patented as an outcome from the current research. The team are hoping to quantify the effectiveness of the net in the laboratory or at the field site. Interestingly, results of lab work have returned similar results to the field site and therefore proven to be a viable (and easier!) location to work at.