The Final Four

March Madness was six months late this year. Huh? On the same day I discovered a male Roseate Skimmer dragonfly (Orthemis ferruginea) at Huntley Meadows Park, I witnessed what could be described as an orgy of odonate mating. Common Whitetails, Great Blue Skimmers, and Twelve-spotted Skimmers — if it were flying then it was mating and mating frequently!

The following gallery of photos features several Twelve-spotted Skimmer dragonflies (Libellula pulchella). All of these individuals are mature males, as indicated by their coloration and terminal appendages. The scratch marks on their abdomen shows they have mated many times.

As it turns out, these were the last Twelve-spotted Skimmers I saw during 2015. I was as close to these guys as I’ve ever been to Twelve-spotted Skimmers  — I think they were simply too tired to care! Please look at the full-size version of each photo in order to appreciate what it’s like to be up close and personal with a male Twelve-spotted Skimmer dragonfly.

23 SEP 2015 | HMP | Twelve-spotted Skimmer (male)

23 SEP 2015 | HMP | Twelve-spotted Skimmer (male)

23 SEP 2015 | HMP | Twelve-spotted Skimmer (male)

23 SEP 2015 | HMP | Twelve-spotted Skimmer (male)

Copyright © 2015 Walter Sanford. All rights reserved.

Twelve-spotted Skimmer dragonfly terminal appendages

Twelve-spotted Skimmer (Libellula pulchella) is a member of the Skimmer Family of dragonflies that is spotted during the summer months at many water bodies in the mid-Atlantic United States, such as the wetlands at Huntley Meadows Park (HMP).

Twelve-spotted Skimmers display sexual dimorphism; terminal appendages may be used to differentiate immature males from females.

Male dragonflies have three terminal appendages, collectively called “claspers,” that are used to grab and hold female dragonflies during mating: an upper pair of cerci (“superior appendages”) and a lower unpaired epiproct (“inferior appendage”).

31 MAY 2014 | HMP | Twelve-spotted Skimmer (young male)

The preceding individual is a young male, as indicated by the white partial pruinescence covering his abdomen. In contrast, the abdomen of the following mature male is completely white.

12 SEP 2014 | HMP | Twelve-spotted Skimmer (mature male)

Female dragonflies have a pair of cerci (superior appendages) that have little or no function.

22 MAY 2015 | HMP | Twelve-spotted Skimmer (female)

Related Resources: Odonate Terminal Appendages.

Copyright © 2015 Walter Sanford. All rights reserved.

Twelve-spotted Skimmer dragonfly (young male)

A Twelve-spotted Skimmer dragonfly (Libellula pulchella) was spotted near a vernal pool at Huntley Meadows Park (HMP). This individual is a young adult male, as indicated by its partial pruinescence, distinctive pattern of wing spots, and terminal appendages. As a mature adult male, its abdomen will be completely covered by white pruinescence.

22 MAY 2015 | HMP | Twelve-spotted Skimmer (young male)

Among dragonflies that exhibit sexual dimorphism, such as Twelve-spotted Skimmers, immature/young males and females are similar in appearance. The pattern of wing spots is a key field mark for identification of Twelve-spotted Skimmer males and females, in addition to differences in their terminal appendages.

22 MAY 2015 | HMP | Twelve-spotted Skimmer (young male)

Editor’s Note: With no disrespect intended toward Kevin Munroe, whom I admire and respect, I feel compelled to point out an error on Kevin’s Twelve-spotted Skimmer page. In the lower-right corner of page 1, an immature male is misidentified as a female. Believe me when I tell you Kevin’s expertise far exceeds mine, but hey, only someone like me with a fixation on odonate terminal appendages would have recognized the immature male’s claspers!

Copyright © 2015 Walter Sanford. All rights reserved.

Twelve-spotted Skimmer dragonfly (female)

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.

22 MAY 2015 | HMP | Twelve-spotted Skimmer (female)

22 MAY 2015 | HMP | Twelve-spotted Skimmer (female)

22 MAY 2015 | HMP | Twelve-spotted Skimmer (female)

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 mark 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.

Look closely at the pattern of wing spots for the female Common Whitetail, in particular, the middle spots on each wing. Notice the shape of each middle spot forms a “spike” that points toward the body of the dragonfly. In contrast, the middle wing spots for female Twelve-spotted Skimmer aren’t “spiked.” An excellent blog post by DSA member Jim Johnson, entitled “ID Challenge #3 Answer,” illustrates the difference in the pattern of wing spots for these two species (using proper terminology).

27 APR 2015 | Huntley Meadows Park | Common Whitetail (female)

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.

Twelve-spotted Skimmer dragonfly (young male)

A Twelve-spotted Skimmer dragonfly (Libellula pulchella) was photographed along the boardwalk at Huntley Meadows Park on 10 September 2014. This individual is a young adult male, as indicated by its partial pruinescence, distinctive pattern of wing spots, and terminal appendages. As a mature adult male dragonfly, its abdomen will be completely covered by white pruinescence.

Among dragonflies that exhibit sexual dimorphism, such as Twelve-spotted Skimmers, immature/young males and females are similar in appearance. The pattern of wing spots is a key field marker for identification of Twelve-spotted Skimmer males and females, in addition to differences in their terminal appendages.

The red berries, shown in the background, are the fruit of Swamp Rose (Rosa palustris); the green globes are the fruit of buttonbush (Cephalanthus sp.).

I love a good shot of a head-tilt!

Copyright © 2015 Walter Sanford. All rights reserved.

Twelve-spotted Skimmer dragonflies (males)

The following photos show two Twelve-spotted Skimmer dragonflies (Libellula pulchella) perching alongside the boardwalk in the central wetland area at Huntley Meadows Park on 12 September 2014. These individuals are adult males, as indicated by their coloration and terminal appendages.

Male 1

Male 2

Related Resources: Digital Dragonflies, presenting high-resolution digital scans of living dragonflies.

• Genus Libellula | Libellula pulchella | Twelve-spotted Skimmer | male | top view
• Genus Libellula | Libellula pulchella | Twelve-spotted Skimmer | male | side view

Eight-spotted Skimmer (Libellula forensis) is a similar looking species of dragonfly found in the western United States, but as I said in a recent post, similar is not the same. Contrast the wing spots nearest the wing tips for males of both species: notice those spots are white for Eight-spotted Skimmers; black for Twelve-spotted Skimmers.

Copyright © 2015 Walter Sanford. All rights reserved.

Twelve-spotted Skimmer dragonfly (adult male)

The preceding photo shows a Twelve-spotted Skimmer dragonfly (Libellula pulchella) perching alongside the boardwalk in the central wetland area at Huntley Meadows Park on 04 September 2014. This individual is an adult male, as indicated by its coloration and terminal appendages.

The soft pastel colors in the background are a mirror image of the blue sky and white clouds overhead, reflected from the hemi-marsh. Look closely at a full-size version of the photo and you can see the sky reflected from the dragonfly’s left eye!

The next photo seems to evoke a different mood, despite the fact that it’s the same dragonfly perching in nearly the same spot.

Related Resources: Digital Dragonflies, presenting high-resolution digital scans of living dragonflies.

• Genus Libellula | Libellula pulchella | Twelve-spotted Skimmer | male | top view
• Genus Libellula | Libellula pulchella | Twelve-spotted Skimmer | male | side view

Editor’s Note: I used a Canon 580EX Speedlite mounted on my Panasonic Lumix DMC-FZ150 superzoom digital camera to shoot this photograph. The 580EX seems to “play nicer” with the Panasonic than my 580EX II. In particular, the 580EX always “wakes up” automatically whenever the camera exits power-saver mode; the 580EX II has to be forced to wake up sometimes (by pressing the “Pilot” button). For more information, see Lessons Learned: How to use a superzoom camera to shoot insect photos.

Copyright © 2014 Walter Sanford. All rights reserved.

Twelve-spotted Skimmer dragonfly (young male)

The following photos show one of two Twelve-spotted Skimmer dragonflies (Libellula pulchella) spotted at Huntley Meadows Park on 31 May 2014. This individual is a young adult male, as indicated by its partial pruinescence, distinctive pattern of wing spots, and terminal appendages. As a mature adult male dragonfly, its abdomen will be completely covered by white pruinescence.

Among dragonflies that exhibit sexual dimorphism, such as Twelve-spotted Skimmers, immature/young males and females are similar in appearance. The pattern of wing spots is a key field marker for identification of Twelve-spotted Skimmer males and females, in addition to differences in their terminal appendages.

The “sparkling bokeh” background shown in the next three photos was caused by out-of-focus points of light reflected from the water surface several feet below the dragonfly.

Editor’s Note: I was surprised to see Twelve-spotted Skimmer dragonflies since I have never seen one earlier than mid-July. Kevin Munroe’s excellent Calendar of [Adult] Flight Periods [for Northern Virginia USA] shows Twelve-spotted Skimmers occur from the second week in May to mid-October.

Copyright © 2014 Walter Sanford. All rights reserved.

Twelve-spotted Skimmer dragonfly (female)

The following photograph shows a Twelve-spotted Skimmer dragonfly (Libellula pulchella) spotted along the boardwalk that goes through the central wetland area at Huntley Meadows Park. This individual is an adult female, as indicated by its coloration and the terminal appendages at the end of its abdomen.

Female Twelve-spotted Skimmer dragonflies appear very similar to female Common Whitetail dragonflies (Plathemis lydia), such as the one shown below, spotted at Meadowood Recreation Area.

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.

Look closely at the pattern of wing spots for the female Common Whitetail, in particular, the middle spots on each wing. Notice the shape of each middle spot forms a “spike” that points toward the body of the dragonfly. In contrast, the middle wing spots for female Twelve-spotted Skimmer aren’t “spiked.” An excellent blog post by DSA member Jim Johnson, entitled “ID Challenge #3 Answer,” illustrates the difference in the pattern of wing spots for these two species (using proper terminology).

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 © 2013 Walter Sanford. All rights reserved.

Twelve-spotted Skimmer dragonfly (male)

The following gallery shows a Twelve-spotted Skimmer dragonfly (Libellula pulchella) spotted along the boardwalk that goes through the central wetland area at Huntley Meadows Park. This individual is an adult male, as indicated by its distinctive pattern of wing spots, pruinescence that covers its abdomen completely, and the terminal appendages at the end of its abdomen.

I love a good head-tilt! (See Photos 3-4.)

Copyright © 2013 Walter Sanford. All rights reserved.