In the course of his recent research, Tolulope Morawo, Ph.D., postdoctoral fellow at Auburn University, struggled to get useful results from tests using a traditional, horizontal four-choice olfactometer (a device for measuring insect response to olfactory stimuli). So, he designed an alternate version with a longer central tube and angled arms to improve the aerodynamics of the odor-laden air; the new design led to much improved results, Morawo says. Here, he tests the attraction of parasitic wasps (Microplitis croceipes) to herbivore-induced plant volatiles in the modified four-choice olfactometer. (Photo credit: Morgan Gregg)