Asynchronous haltere input drives specific wing and head movements in Drosophila

Halteres are multifunctional mechanosensory organs unique to the true
flies (Diptera). A set of reduced hindwings, the halteres beat at the same
frequency as the lift-generating forewings and sense inertial forces via
mechanosensory campaniform sensilla. Though haltere ablation makes stable
flight impossible, the specific role of wing-synchronous input has not
been established. Using small iron filings attached to the halteres of
tethered flies and an alternating electromagnetic field, we experimentally
decoupled the wings and halteres of flying Drosophila and observed the
resulting changes in wingbeat amplitude and head orientation. We find that
asynchronous haltere input results in fast amplitude changes in the wing
(“wing hitches”), but does not appreciably move the head. In multi-modal
experiments, we find that wing and gaze optomotor responses are disrupted
differently by asynchronous input. These effects of wing-asynchronous
haltere input suggest that specific sensory information is necessary for
maintaining wing amplitude stability and adaptive gaze control.

平衡棒（halteres）是双翅目（Diptera）昆虫独有的多功能机械感觉器官。这类器官为一对退化的后翅，其拍打频率与产生升力的前翅保持一致，并通过机械感觉钟形感器（campaniform sensilla）感知惯性力。尽管切除平衡棒会使稳定飞行无法实现，但与翅膀同步的感官输入的具体作用尚未得到明确阐释。本研究通过在束缚飞行果蝇（Drosophila）的平衡棒上附着细小铁屑，并施加交变电磁场，实验性地实现了飞行个体翅膀与平衡棒的运动解耦，进而观察由此引发的翅搏振幅与头部朝向的变化。我们发现，异步的平衡棒输入会导致翅膀出现快速的振幅波动，即“翅搏卡顿”，但不会使头部发生明显位移。在多模态实验中，我们还发现异步输入对翅膀运动与凝视视觉运动响应的干扰模式存在显著差异。上述翼异步平衡棒输入所产生的效应表明，特定的感官信息对于维持翅搏振幅稳定性与适应性凝视控制是不可或缺的。