Meeting Abstract
The mechanisms by which sensory systems process information can change to meet specific behavioral and ecological demands. Often, behavioral state changes can alter the functioning of a sensory system, or modify interactions between multiple sensory systems. In flies, the modified hindwings known as halteres provide fast, precise mechanosensory information, and are essential for flight. Oscillations of the halteres during flight provide timing signals for wing-steering behavior, and enable the detection of Coriolis forces during body rotation. Although many families of flies use their halteres only for flight, haltere oscillations also occur during walking in one of the largest and successful groups of flies, the Calyptratae (a clade including house flies, flesh flies, and blow flies). Using high-speed videography of both flesh flies (Sarcophagidae) and blow flies (Calliphoridae), we show that large haltere oscillations occur consistently during leg movement behaviors. Recordings of muscle activity showed that these oscillations are not driven by the large indirect muscles of the thorax, as they are during flight. Ablating the fields of campaniform sensilla at the base of the haltere eliminates the haltere oscillations, demonstrating that haltere-driven feedback is necessary for the haltere muscles to maintain the oscillations during walking. Taken together, our results suggest that the circuits driving haltere oscillation may function differently during walking and flying, resulting in differences in both motor output and sensory information processing.
