SSS 2010-03-10（在线收听）

You know how uncomfortable it feels when you really have to go to the bathroom? And you have to hold it in? If researchers get their way, disease-carrying mosquitoes will spend their last moments being that uncomfortable. Cornell University scientists have been trying to disrupt the life cycle of Aedes aegypti mosquitoes, which spread dengue fever. The mosquitoes pick up the virus when they feed on one human and transmit it in their saliva to their next victim.

There’s no vaccine for dengue, and no fully protective treatment. So the only recourse has been to figure out how to best kill the mosquitoes themselves. Here’s where urination comes in. When the mosquito takes a blood meal, it has to get rid of fluid and salt so it doesn’t overload—and die. Scientists have discovered a key protein in the renal tubes of these mosquitoes that helps with the necessary excretion. Blocking the protein keeps a mosquito from urinating. Without whizzing, they become too heavy to fly away. The researchers say they’re thus more likely to be swatted or eaten. So look for new insecticides that stop mosquitoes from lightening their liquid load. With fatal results.