Double-striped Bluet (Enallagma basidens)

The double-striped bluet is a species of damselfly in the family Coenagrionidae. This species grows to lengths 21–28 mm. Its common name comes from the peculiar black shoulder stripe, which is divided in two by a thin blue stripe. This is the key identification characteristic; no other damselfly has a shoulder stripe that looks like this one.