"Common Green Darner", a dragonfly of the Family Aeshnidae (Order Odonata). Found throughout the United States and down to Panama, up into in southern Canada and Alaska, parts of Asia, and in northern Europe.
Males have blue abdomens with a black stripe, while females are brown with pale blue to greenish-yellow spots. Both have clear wings. They migrate, in both the spring and fall. They feed on insects, including mosquitoes.
They live near stagnant or slow-moving fresh water. The males are often seen racing and fighting over the water, protecting their territory.