Meeting Abstract
Landing maneuvers in flies may be decomposed into a sequence of modular behaviors such as body deceleration, extension of legs, and body rotations to ensure that the body is parallel to the landing substrate during touchdown. The variability in the conduct of landing maneuvers makes it difficult to identify the general rules that govern this behavior. Previous studies have relied on tethered preparations to study landing behaviors, but tethering constrains some behavioral modules to operate in an open feedback control loop while others remain in closed-loop, causing experimental artefacts. On the other hand, freely flying insects are hard to precisely control causing behavioral variability that is difficult to control. We elicited landing behaviors in houseflies (Musca Domestica) on vertical or inverted horizontal substrates, which could be captured accurately using multiple high-speed video cameras. Our experiments show that flies land in a smooth and controlled manner if they satisfy specific criteria. Flies landing on the vertical surface and those landing smoothly on the inverted surface initiated deceleration at fixed distances from the substrate, in direct proportion to the component of flight velocity normal to the landing surface. The ratio of distance to perpendicular velocity at the onset of deceleration was conserved, despite large differences in the mechanics of the vertical vs. inverted landings. Flies extended their legs independently of distance from the landing surface, and the component of approach velocity normal to the surface, regardless of the orientation of the landing substrate. Together, our results suggest that the visual initiation of deceleration is robust to orientation of the landing surface.
