Seasonal and annual variations on wing shape and wing size of eight damselfly species (Odonata: Calopterygidae, Coenagrionidae)

摘要

This study examined the effects of seasonal and annual variations on wing shape and wing size of eight damselfly species in central Texas. Comparisons included i) populations collected early in the flight season versus those collected late in the flight season, and ii) populations collected from the same locations during several annual flight seasons. We found widespread differences in both wing shape and body size in males and females among most species examined. Wing shape of male and female damselflies collected early varied significantly from those collected late in the flight season for all locations and years sampled. Damselflies emerging early in the flight season were significantly larger than those emerging late, except for Enallagma civile showing opposite results. Populations of six species sampled in different years at the same location were compared, and significant differences in wing shape and size occurred in no females and in males of only two species. Our results suggest that differences in seasonal and year-to-year environmental conditions frequently influence wing shape and body size in multiple damselfly species.