Meeting Abstract

P1.96  Thursday, Jan. 3  Checks on the flex: Structures for maintaining flexible corrugation in odonate wings DONOUGHE, S. T.*; CRALL, J. D.; CHRISTMAS, P. N.; WEISEL, J. W.; MERZ, R. A.; Swarthmore College; Swarthmore College; Swarthmore College; University of Pennsylvania; Swarthmore College seth.donoughe@gmail.com

The membranous wings of dragonflies and damselflies (Anisoptera and Zygoptera of the Odonata) are supported by rigid veins linked, in some cases, with flexible joints. Using fluorescence microscopy we mapped the distribution of the elastic protein resilin in joints on the dorsal and ventral sides of the wings in a diversity of species revealing a distinct pattern specific to each sub-order. In dragonflies, resilin was only along the transverse veins at the bottom of the �valleys� of the corrugated wings. In damselflies, however, resilin occurred in joints on both �mountains� and �valleys.� Through scanning electron microscopy we saw that in some cases knobs or spikes of cuticle projected into the fold of a joint. In dragonflies the association of knobs and spikes with flexible joints is rare (e.g. 19 of 180 joints on a wing) and dispersed across the wing. In damselflies the association is common (e.g. 68 of 78) and typical of joints along the transverse veins. It appears that the resilin distribution and the configuration of a joint combine to function as a mechanism that creates asymmetrical stiffness in joints. To test this, isolated veins were pivoted with a glass fiber and the relative deformations of the fiber and joint measured. We calculated the flexibility of joints and confirmed that the asymmetries in joint construction are associated with a preferential direction of bending. These findings suggest that resilin and the structure of the vein joints are involved in the corrugation and flexibility of the odonate wing as a whole and influence wing deformation during flight.