The twelve-spotted skimmer is named after the 3 black spots on each wing – for a total of 12 black spots.  They are often seen perched on twigs by the water’s edge.  This skimmer is a male.  The females have a yellowish body with a brown/black stripe down the center.

Found throughout most of the United States and much of Canada.  This photo was taken at Morton Arboretum, in Lisle IL.