On a trading estate outside Oxford some weird science is going on. Behind security doors and “Keep out” signs, red-coated technicians are breeding one of the world’s most prolific killers. The laboratory walls are lined with mesh tanks, each containing what looks like a small, angry rain cloud. Get close enough to the gauze, though, and you can see each cloud is a pulsing swarm of mosquitoes.
These aren’t the common or garden variety that causes a nuisance at summer barbecues. These are the kind that spreads yellow fever, dengue fever and the zika virus — diseases that together kill tens of thousands of people worldwide. Now scientists at a British company have found a way to fight back by planting a “kill switch”.