A Twelve-spotted Skimmer dragonfly (Libellula pulchella) was spotted perched in a small meadow near a vernal pool at Huntley Meadows Park (HMP). This individual is a female, as indicated by its coloration and terminal appendages.
Female Twelve-spotted Skimmer dragonflies appear very similar to female Common Whitetails.
Although males quite different, female Common Whitetail poses identification problem, as she has same 12 wing spots. In addition to being distinctly smaller, female Whitetail has series of yellowish-whitish spots not contacting edge of each abdominal segment, whereas female Twelve-spotted has continuous parallel yellow stripes on either edge of abdomen. In side view of thorax, female Whitetail has additional yellow dot in front of anterior yellow stripe, lacking in Twelve-spotted. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 9017-9021). Princeton University Press. Kindle Edition.
In summary, the key field marker that may be used to differentiate female Twelve-spotted Skimmers from female Common Whitetail Skimmers is the stripe along both sides of their abdomens: Twelve-spotted Skimmers have two stripes of continuous rectangles; Common Whitetails have two stripes made of separated triangles.
A Common Whitetail dragonfly (Plathemis lydia) was spotted about a month earlier at the same location. This individual is a female, as indicated by its coloration, pattern of wing spots, and terminal appendages.
Common Whitetail dragonflies, including both males and females, are in fact quite common. In my experience, female Twelve-spotted Skimmers are an uncommon spotting. I wonder how many Twelve-spotted Skimmer females are overlooked by this sort of dismissive thinking: “Nothing to see here folks, it’s just another female Common Whitetail. Move along.”
Related Resources: Digital Dragonflies, presenting high-resolution digital scans of living dragonflies.
- Genus Libellula | Libellula pulchella | Twelve-spotted Skimmer | female | top view
- Genus Libellula | Libellula pulchella | Twelve-spotted Skimmer | female | side view
- Genus Libellula | Libellula lydia [sic] | Common Whitetail | female | top view
Copyright © 2015 Walter Sanford. All rights reserved.