A Great Blue Skimmer dragonfly (Libellula vibrans) was spotted on 20 May 2015 during a photowalk alongside the wetlands at Huntley Meadows Park (HMP). This individual is a young female, as indicated by its coloration and terminal appendages.
The young female was sheltering in vegetation close to the ground.
She was quite skittish, flying to a new location whenever I violated her comfort zone.
Look closely at the full-size version of the following annotated image. Female Great Blue Skimmers have a pair of flanges beneath their eighth abdominal segment (S8) that are used to scoop water when laying eggs (oviposition), hence the family name “Skimmer.” Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.
Immature Great Blue Skimmer dragonflies and immature Slaty Skimmer dragonflies (Libellula incesta) — including both females and males — look very similar. In my opinion, the best field marker for differentiating the two species is femur coloration: Great Blue Skimmer femora are mostly tan; Slaty Skimmer femora are mostly black.
The following female Slaty Skimmer was spotted along the “Hike-Bike Trail” at Huntley Meadows Park. Contrast the difference in coloration of the Slaty Skimmer femurs (below) with the Great Blue Skimmer femurs (above).
- Great Blue Skimmers – “The femora are pale over their basal half with the remaining length, tibiae and tarsi black.”
- Slaty Skimmer – “The legs are black with brown only at their extreme bases.”
Digital Dragonflies: presenting high-resolution digital scans of living dragonflies.
- Genus Libellula | Libellula vibrans | Great Blue Skimmer | female | top view
- Genus Libellula | Libellula vibrans | Great Blue Skimmer | female | side view
Digital scans by G & J Strickland:
- L. incesta female #1 (Slaty Skimmer) — lighter tan face
- L. incesta female #2 (Slaty Skimmer) — brown face
- L. incesta female #3 (Slaty Skimmer) — old female, very pruinose
Copyright © 2015 Walter Sanford. All rights reserved.
Tags: cerci, flanges, Great Blue Skimmer dragonfly, Huntley Meadows Park, immature female, Libellula incesta, Libellula vibrans, oviposition, pruinescence, Skimmer Family, Slaty Skimmer dragonfly, terminal appendages, young female