Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Kiel 24118, Germany.
Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Kiel 24118, Germany.
Acta Biomater. 2019 Dec;100:10-17. doi: 10.1016/j.actbio.2019.09.027. Epub 2019 Sep 19.
Stink bugs have wing coupling mechanisms to synchronize flapping of their wings. The wing coupling is performed through a clamp-like structure on the fore wing (i.e. hemelytron) and a rolled margin on the hind wing. Here we used modern imaging techniques to investigate structural characteristics and material composition of the wing coupling of the stink bug Nezara viridula. We found that the surfaces of the clamp-like structure and the rolled margin are covered by highly-sclerotized microtrichia, which are expected to reduce friction between the wings during flapping flight. Micro-force measurements showed that fore and hind wings can be coupled only in certain angles ranging from 40.6° to 267.7° The results further showed that the force required to uncouple fore and hind wings is maximal for a range of angles which they make with each other during flight (127.1°-238.9°). In contrast to previous observations on some other insect species, the removal of the wing coupling in stink bugs led to complete loss of flight ability. In summary, we concluded that the shape, material composition and orientation of the coupling structure guarantee a robust fore wing to hind wing coupling during flight and a fast, easy uncoupling at rest. STATEMENT OF SIGNIFICANCE: Although the coupling mechanism of insect fore wing and hind wing has long been described, the functionality of this mechanism still remains largely unknown. In the present work, using a combination of modern imaging techniques and mechanical testing, we studied the functional morphology of the fore wing-hind wing coupling mechanism of the stink bug Nezara viridula. Our study reveals the crucial role of the mechanism in the flight ability of the stink bug and sheds light on the structure-property-function relationships of the functional diptery in insects.
臭虫具有翅膀耦合机制，以同步其翅膀的拍打。翅膀耦合通过前翅（即半翅）上的夹状结构和后翅上的卷边边缘来完成。在这里，我们使用现代成像技术研究了臭虫 Nezara viridula 的翅膀耦合的结构特征和材料组成。我们发现，夹状结构和卷边边缘的表面覆盖有高度硬化的微刚毛，这有望减少拍打飞行过程中翅膀之间的摩擦。微力测量表明，前翅和后翅只能在 40.6°至 267.7°的特定角度耦合。结果进一步表明，在飞行过程中前翅和后翅相互形成的角度范围内，分离前翅和后翅所需的力最大（127.1°-238.9°）。与以前对其他一些昆虫物种的观察结果相反，臭虫翅膀耦合的去除导致完全丧失飞行能力。总之，我们得出结论，耦合结构的形状、材料组成和方向保证了在飞行过程中前翅和后翅的牢固耦合，并在静止时快速、轻松地分离。 意义声明：尽管昆虫前翅和后翅的耦合机制早已被描述，但该机制的功能仍在很大程度上未知。在本工作中，我们使用现代成像技术和力学测试相结合的方法，研究了臭虫 Nezara viridula 的前翅-后翅耦合机制的功能形态。我们的研究揭示了该机制在臭虫飞行能力中的关键作用，并阐明了昆虫功能性二翅目结构-性质-功能关系。
