Sex pheromone could save thousands

 作者:公良鲨宫     |      日期:2019-03-08 07:14:01
By Andy Coghlan LUST may soon spell the end for a tiny insect whose bite kills eight thousand South Americans each year and which debilitates hundreds of thousands more. Chemists in Britain and Japan have identified and synthesised the pheromone produced by male sandflies, and say this could be used to trap the disease-carrying female bug. Female sandflies spread the protozoan Leishmania donovani chagasi. This parasite causes leishmaniasis, a disease that brings severe fever, weight loss, joint pain and swelling of the spleen and liver. Victims may be hideously disfigured by skin lesions, and many die of secondary diseases such as TB, pneumonia and dysentery. At present, the only reliable way to control the flies is by mass spraying with powerful pesticides such as DDT and malathion, although this is seldom practical in densely populated urban areas. Culling of carrier animals such as dogs and armadillos is another control measure, but is rarely effective. Mosquito nets are useless because the holes are too large to keep out the sandflies, which are just 3 millimetres long. But John Pickett and his colleagues at the Institute for Arable Crops Research in Rothamsted, Hertfordshire, have now worked out the structure of the male sandfly pheromone. This made it possible for researchers in Japan, led by Kenji Mori of the Science University of Tokyo, to synthesise the compound, which is a member of the large family known as sesquiterpenes (Chemical Communications, p 355). “Rather than having to spray the world, you can attract the insects to a single place where you can deal with them,