Data from: Allometry of wing twist and camber in a flower chafer during free-flight: How do wing deformations scale with body size?

Intraspecific variation in adult body mass can be particularly high in some insect species, mandating adjustment of the wing’s structural properties to support the weight of the larger body mass in air. Insect wings elastically deform during flapping, dynamically changing the twist and camber of the relatively thin and flat aerofoil. We examined how wing deformations during free-flight scale with body mass within a species of rose chafers (Coleoptera: Protaetia cuprea) in which individuals varied more than three-fold in body mass (0.38-1.29g). Beetles taking off voluntarily were filmed using three high-speed cameras and the instantaneous deformation of their wings during the flapping cycle was analysed. Flapping frequency decreased in larger beetles but, otherwise, flapping kinematics remained similar in both small and large beetles. Deflection of the wing chord-wise varied along the span, with average deflections at the proximal trailing edge higher by 0.2 and 0.197 wing-lengths compared to the distal trailing edge in the downstroke and the upstroke, respectively. These deflections scaled with wing chord to the power of 1.0, implying a constant twist and camber despite the variations in wing and body size. This suggests that the allometric growth in wing size includes adjustment of the flexural stiffness of the wing structure to preserve wing twist and camber during flapping.部分昆虫物种的成虫体重种内变异幅度显著，这要求其调整翅膀的结构特性，以支撑体型更大个体在空中的体重负载。昆虫翅膀在扑动过程中会发生弹性变形，动态改变相对轻薄扁平翼型的扭转与弯度。本研究以玫瑰金龟子（鞘翅目：Protaetia cuprea）为研究对象，该物种个体体重差异可达三倍以上（0.38~1.29g），我们借此探究了其自由飞行时的翅膀变形如何随体重发生尺度缩放。研究采用三台高速摄像机拍摄自愿起飞的甲虫，并对其扑动周期内翅膀的瞬时变形进行分析。体型更大的甲虫扑动频率降低，但大小个体的其余扑动运动学特征整体保持一致。翼弦方向的翼面挠度沿翼展方向存在差异：下挥阶段近端后缘的平均挠度较远端后缘高0.2个翼长，上挥阶段则高0.197个翼长。此类挠度与翼弦呈1.0次方的尺度缩放关系，表明尽管翅膀与体型存在变异，翼型的扭转与弯度仍保持恒定。这意味着翅膀尺寸的异速生长过程中，会同步调整翅膀结构的弯曲刚度，以维持扑动过程中的翼型扭转与弯度。