Dragonflies (IMAGE) University of Würzburg Caption Different coloured dragonfly species (from left to right): The Small Whiteface (Leucorrhinia dubia) is a dark species that flies mainly in spring and early summer. The Keeled Skimmer (Orthetrum coerulescens), a light-coloured species that flies mainly in midsummer. The Black Darter (Sympetrum danae), a dark species that flies mainly in late summer and fall. Credit Christian Hof / Uni Würzburg Usage Restrictions No further restrictions License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.