Morphological and mechanical characterisation of the hindwing nodus from the Libellulidae family of dragonfly

In this communication, the morphologies and mechanical characteristics of nodi from the hindwings of seven Indonesian Libellulidae dragonfly species are identified. Geometrical analyses reveal that in all species, the shape of dorsal face resilin is relatively long and thin while ventral face resilin covers a greater surface area than dorsal face resilin, and is shaped like a hook. Finite element analyses reveal that the magnitude of strain energy may differ considerably between species, even though the locations of highest strain energy are usually the same. Importantly, a correlation is found to exist between the mechanical forces that build up in the resilin, the face under investigation (dorsal or ventral) and the elongational shape factor of the resilin.