RESEARCH PROJECT PROPOSAL FOR THE YEAR 2022-2023 Project title: Acoustic levitation and free fall responses of hoverflies HOST RESEARCH GROUP Name of the group: Institute of Movement Sciences/Biorobotics (Marseille, France) Host institution: CNRS/Aix-Marseille Université Website: https://ism.univ-amu.fr/ INFORMATION ON THE PROJECT This project focuses on the study of multi-sensory fusion in hoverfly during free fall. Once dropped in free fall by means of an acoustic levitator, hoverfly have (or not) to trigger the wingbeat to stabilize their flight and strop the fall. To do that, we have more and more evidences that flies use leg proprioception, antennae and vision to detect the fall and drive various reflexes in charge of stabilizing the flight. When placed in contact with a surface, leg proprioception is used to measure the orientation with respect to gravity before the take-off. Antennae can be used to measure the air-flow direction. Vision through the dorsal-light-response (DLR) allows the fly measure the surrounding light distribution and thus a vertical reference, the sky being brighter than the ground. We will particularly study the righting behavior in free fall. The main advantage of using an acoustic levitator is to suppress the leg proprioception prior to the fall. The principal problem is the spin of the object in levitation but solutions exist to remove the spin. We will also change the experimental conditions (e.g., light position) to modify the fly’s response. Example of a flying insect placed in acoustic levitation References 1. R. Goulard, J-L. Vercher and S. Viollet (2016), To crash or not to crash: how do hoverflies cope with free-fall situations and weightlessness?, J. of Experimental Biology, vol. 219, 2497-2503. 2. A. Verbe, L. Varennes, J-L Vercher and S. Viollet (2020) How do hoverflies use their righting reflex?, J. of Experimental Biology, vol. 223:jeb215327. 3. Asier Marzo, Adrian Barnes, and Bruce W. Drinkwater , "TinyLev: A multi-emitter single-axis acoustic levitator", Review of Scientific Instruments 88, 085105 (2017) https://doi.org/10.1063/1.4989995 Techniques that will be used by the student: Learn how to build an acoustic levitator for insects, analyze fly body movement with fast cameras, define an experiment with various conditions, behavior modelling. Background/skills requested: Electronics, Physics, Ethology, Image Processing Salary: about 600€/month (public transport fees are covered) RESEARCH SUPERVISOR: Names: Stéphane Viollet (CNRS Research Director) E-mail: stephane.viollet@univ-amu.fr