PDF(Pubmed)
Abstract：
An insect\'s wingbeat frequency is a critical determinant of its flight performance and varies by multiple orders of magnitude across Insecta. Despite potential energetic benefits for an insect that matches its wingbeat frequency to its resonant frequency, recent work has shown that moths may operate off their resonant peak. We hypothesized that across species, wingbeat frequency scales with resonance frequency to maintain favourable energetics, but with an offset in species that use frequency modulation as a means of flight control. The moth superfamily Bombycoidea is ideal for testing this hypothesis because their wingbeat frequencies vary across species by an order of magnitude, despite similar morphology and actuation. We used materials testing, high-speed videography and a model of resonant aerodynamics to determine how components of an insect\'s flight apparatus (stiffness, wing inertia, muscle strain and aerodynamics) vary with wingbeat frequency. We find that the resonant frequency of a moth correlates with wingbeat frequency, but resonance curve shape (described by the Weis-Fogh number) and peak location vary within the clade in a way that corresponds to frequency-dependent biomechanical demands. Our results demonstrate that a suite of adaptations in muscle, exoskeleton and wing drive variation in resonant mechanics, reflecting potential constraints on matching wingbeat and resonant frequencies.
摘要：
昆虫的翅拍频率是其飞行性能的关键决定因素，并且在昆虫纲中变化了多个数量级。尽管昆虫的翼拍频率与其共振频率相匹配可能有能量益处，最近的工作表明，蛾可能会偏离其共振峰。我们假设跨物种，翼拍频率与共振频率成比例，以保持有利的能量学，但是在使用频率调制作为飞行控制手段的物种中存在偏移。蛾超家族Bombycoidea是检验这一假设的理想选择，因为它们的翼拍频率因物种而异，尽管形态和驱动相似。我们用材料测试，高速摄像和共振空气动力学模型，以确定昆虫飞行装置的部件(刚度，机翼惯性,肌肉拉伤和空气动力学）随翼拍频率而变化。我们发现蛾的共振频率与翼拍频率相关，但是共振曲线形状（由Weis-Fogh数描述）和峰位置在进化枝内以与频率相关的生物力学需求相对应的方式变化。我们的结果表明，肌肉的一系列适应，共振力学中的外骨骼和机翼驱动变化，反映对匹配的翼拍和共振频率的潜在约束。
