Wing parameters in Celithemis dragonflies
The evolution of dragonfly wings is subjected to both natural and sexual selection pressures. The Targeted Odonata Wing Digitization (TOWD) aims at scanning the wings of all North American dragonfly species. Using the genus Celithemis Hagen, 1861, as an example, we demonstrate the potential of this unique image database for quantifying and analyzing wing parameters in the Odonata. Based on area measurements of wings and wing spots taken from wing scans mainly using standard imaging software, and on wing weight measurements of selected Celithemis species, we established basic relationships of these parameters for the genus and discuss them with regard to the ecology and behavior of the species. Future research should focus on a wider range of species with similarly colored wings and should consider further characters (e.g. wing shape) to determine the evolutionary factors acting on the dragonfly wing.