Spangled Skimmer

The spangled skimmer grows to nearly 2 inches long. Each of the 4 wings has a white spot beside a black spot on the outer leading edge.

• Males are blue with a dark head.
• Females are dark brown with lengthwise yellow stripes, and darkish wingtips.

Learn more about the spangled skimmer and other dragonflies (suborder Anisoptera) in their group entry.

The spangled skimmer is a good dragonfly to learn a new anatomy term that can help you identify other dragonflies: pterostigma. This is the name of the particular narrow cell (a section of wing membrane outlined with veins), along the leading edge of the forewing, that in many dragonflies is black, white, and/or brown, and thickened.

• Because it adds weight at that part of the wing, the pterostigma helps reduce vibrations that would prevent dragonflies from gliding efficiently. Having pterostigmata can increase a dragonfly's speed as much as 25 percent.
• The coloring of the pterostigmata, along with other body colorations, probably helps dragonflies to recognize each other, just as it helps people to identify the species. In the spangled skimmer, the white and black pterostigma cell on each wing adds the distinctive "spangle" to this skimmer.