BELLEVUE, Wash. -- A quarter-century ago, American rocket scientists proposed the "Star Wars" defense system to knock Soviet missiles from the skies with laser beams. Some of the same scientists are now aiming their lasers at another airborne threat: the mosquito.

To locate individual mosquitoes, light from the flashlights hits the tank across the room, creating tiny mosquito silhouettes on reflective material behind it. The zoom lens picks up the shadows and feeds the data to the computer, which controls the laser and fires it at the bug.

A mosquito hovers into view. Suddenly, it bursts into flame. A thin plume of smoke rises as the mosquito falls. At the bottom of the screen, the carcass smolders.

Not only can the laser target a mosquito, it can also tell a male from a female based on wing-beat.

That's a crucial distinction, since only females feed on blood and thus transmit disease. Males in the wild eat sugary plant nectar. (In the lab they get raisins.)