Glass beads pick up scents after being handled. The beads will be loaded into an instrument that separates and identifies compounds in the residue. He and his colleagues present their latest findings in the Feb. 15 Analytical Chemistry . To gauge the mosquitoes' reaction to chemicals, the researchers use a simple setup that they call an olfactometer. It consists of three clear plastic cages stacked on top of one another, each connected to a pair of cylindrical ports.
Screens divide the attractants from the insects.
During a test, the researchers place potential attractants in the ports and blow gentle streams of air into the cage. If the mosquitoes like what they smell, they fly upwind toward the attractant. The researchers then tally the number of insects in the port. To account for differences in mosquito mood, the Gainesville group tests the three cages of mosquitoes in a random order at three different times of the day. On some days, the mosquitoes don't respond as well.