Meeting Abstract

73.2  Monday, Jan. 6 08:30  Inability to make bilateral olfactory comparisons affects the plume tracking flight of the moth, Manduca sexta. COLEMAN, DM*; WILLIS, MA; Case Western Reserve University; Case Western Reserve University dmc125@case.edu

Males of the hawkmoth Manduca sexta use their olfactory system to identify and track airborne plumes of female pheromone, but how they maintain contact with the plume is unresolved. Recent studies suggest they may compare odor cues from each antenna to remain near the center of the plume. If bilateral odor comparisons are important, we predict that moths with one antenna will track a pheromone plume, but their success locating the source and the structure of their behavior will be altered. To test this idea, we compared the tracking behavior of M. sexta males with one antenna to intact controls. Antennal removal was conducted in two ways: (1) surgical removal of an antenna 4 hours prior to experiments and (2) surgical removal of an antennal imaginal disc from the last larval stage prior to metamorphosis. The adult antennae of insects that undergo complete metamorphosis develop from bundles of determinate cells that lay dormant through the larval stages known as imaginal discs. Adult moths with only one antenna developed after removing an antennal imaginal disc from male larvae. In this study, 96% of the controls found the odor source with successively significantly fewer of antennectomized moths (44%) and imaginal disc removal moths (24%) locating the source. The flight paths of antennectomized and imaginal disc removal moths were also different from the controls, and each other. These results support the idea that M. sexta uses odor information detected on both antennae to maintain contact with a plume and track it to the source. We thank Jen Milligan and John Dutton for their assistance. DMC was funded by the Support of Undergraduate Research and Creative Endeavors center at CWRU and MAW was supported by a NSF grant IOS-1121498.