Biology

Tanvi Deora
University of Washington, Seattle

Flying insects perform very fast, yet exquisitely controlled flight maneuvers. These rapid flight maneuvers require rapid and precise sensory feedback and control mechanisms. My talk will explore how rapid biomechanical control, in addition to sensori-motor processes, play key roles in shaping flight behaviors.
Dipteran insects flap both wings and a specialized set of mechanosensors organs; the halteres, often at rates greater than 100 Hz. Despite moving at such rapid rates, they remain perfectly synchronized with sub-millisecond precision. How do flies maintain such tight coordination when timing demands exceed the limits of neural control? Using high speed videography and functional anatomy including x-ray microtomography, we demonstrate that mechanical linkages within the exoskeleton provide rapid and yet precise coordination between wings and halteres. These specialized organs, the halteres provide information about gyroscopic forces resulting from body rotations. They are lined with strain sensing neurons that transform the strain resulting from these gyroscopic (and other inertial) forces into neural signal with high temporal precision. Hence, these strain sensors provide very precise timing cues about the position of the haltere, and hence body rotations to help stabilize flight. How did flies evolve such specialized mechanosensors to provide very precise timing cues? To understand the evolutionary underpinning of specialized time encoding sensors, we studied the evolutionary predecessors of haltere; insect wings. Like halteres, wing surfaces are covered with strain sensors. We developed a novel technique of focal heating the sensors and integrated it with high speed videography and electrophysiology to reveal haltere-like response properties of wing sensors to local mechanical deformations. These sensori motor mechanisms underlying flight control shapes their ecological interactions. Finally, I will discuss how insects like moths and butterflies use mechanosensory information from their mouthparts to acquire rapid and precise tactile cues while feeding from flowers, enabling the ecological relevant task of plant pollination. By interrogating insect’s ability to use vision and mechanosensory information to learn flower properties including shape, texture, and color, I aim to link the proximate questions of rapid neural control of flight to broader ecological implication of how these mechanisms shape plant-insect pollinator coevolution.