Curious dragonfly wing structures

Curious dragonfly wing structures

Observation - Curious dragonfly wing structures - Global. Description: I snapped this darter in southern France last Sept. I think it's a Red-veined Darter but I am VERY curious about the red bead-like structures on the wings.

I snapped this darter in southern France last Sept. I think it's a Red-veined Darter but I am VERY curious about the red bead-like structures on the wings.