Malaria is among the world’s worst scourges. In 2016 the disease, which is caused by a parasite and transmitted by mosquitoes, infected 194 million people in Africa and caused 445,000 deaths.

But biologists now have developed a way of manipulating mosquito genetics that forces whole populations of the insect to self-destruct. The technique has proved so successful in laboratory tests that its authors envisage malaria could be eliminated from large regions of Africa within two decades…