Meeting Abstract
Insect flight initiation requires closely-coordinated reflexes, like antennal positioning, head motion, wing initiation and leg extension. During rapid maneuvers, insects actively move their head to reduce motion blur. In Diptera, this behavior is mediated by vision and rapid mechanosensory feedback from halteres, the modified hindwings. How do non-Dipteran insects lacking halteres stabilize gaze in rapid timescales, especially in low light when visual transduction is slow? To address this, we measured compensatory head movements in tethered Oleander hawkmoths, Daphnis nerii in response to variable-frequency roll stimuli in dark vs. light conditions. Normal moths could not gaze-stabilize for low-frequency roll stimuli in low light, but they could under bright light. Interestingly, at high roll frequency in dark, moths could gaze-stabilize, suggesting that non-visual cues are used for head stabilization. We tested the hypothesis that antennal mechanosensors mediate this feedback. Moths with detached flagella did not stabilize their head in low light at all roll frequencies and their performance under bright light was worse than antennae-intact moths. Flagella-reattached moths performed similarly to those with intact antennae. Thus, both vision and antennal mechanosensory feedback are required for head stabilization.
