With worries high over West Nile Virus and encephalitis in the US, and over malaria in much of the world, what we clearly need is a good mosquito repellent. In an excellent public service, and interesting read, The Globe’s Gareth Cook takes a timely look at recent development of some new ones. The science of insect repellents, he reports, is enjoying a renaissance of sorts. An international group is launching an $8.5 million research program to find even better ones, with the first step to understand more about mosquitoes’ “exquisite sense of smell.” Skeeters, it says here, can track a person down from 100 feet away, following the odor of human sweat molecule by molecule.
The story has a bit on the history and drawbacks of DEET, the reigning king of mosquito repellents, with updates on new, effective, and sometimes odorless formulations. One scientist has genetically altered fruit flies to form mosquito receptors for odors (drosophila are easier to work with than mosquitoes), and another remembered some folk knowledge of his grandfather’s and discovered some new botanical sources of repellents. The story also relieves a concern by the Tracker about DEET. He, and his son-in-law, put some on a couple of grandsons recently while mumbling about being careful not to lick it. One of the little guys worried the rest of the day he’d been poisoned. It is a widespread misconception, it says here, that it is noticeably toxic for anybody except kids under age two. But it does smell, and does dissolve some plastics and synthetic fabrics.