The Red-veined Darter favours coastal habitats, mainly areas with shallow pools, which warm up quickly, enabling rapid larval development, which then enables a bimodal flight pattern. In other words they uniquely have 2 generations per year, the first being active in May & June, while the later breed are in flight in August and September. Not quite uniquely, but rarely this species also has females which are more colourful than the males, hence I've shown the female here.