Meeting Abstract
Flying or swimming animals tracking odor plumes through air or water typically generate different looking paths than those walking or crawling on the substrate. These differences could arise from: (1) changes in flows and odor plumes resulting from environmental differences between the free stream and boundary layers near the substrate, (2) differences in the odor inputs of animals flying or swimming rapidly vs. walking slowly through their environments, or (3) different control rules used when walking or flying. It has been proposed that insects walking slowly along plumes in boundary layer flows use spatial cues generated from comparisons across their bilaterally symmetrical antennae, while insects flying rapidly through plumes in free stream flows may only be able to use the timing of odor encounters. Insects are ideal organisms to test these ideas because many of them track odors while flying and walking, providing the opportunity to observe behavioral changes that occur as they transition from flying to walking. Results from our studies of male oriental fruit moths, Grapholita molesta, as they transition from flying to walking plume tracking, show that the tracks of intact individuals change from typical side-to-side zigzag in flight to walking a nearly straight line to the odor source. Individuals that have had either antenna surgically removed change from symmetrical zigzag tracks identical to flying males, to walking tracks that loop toward their intact antenna (left or right). Comparisons of these results to walking tracks generated in clean air confirm and extend these results by showing that in the absence of odor all males walk in a straight line. This work was supported by NSF grant IOS-1121498.
