Posts Tagged ‘sexual dimorphism’

Painted Skimmer dragonfly (teneral female)

March 19, 2017

Painted Skimmer dragonfly (Libellula semifasciata) was spotted at a vernal pool in Huntley Meadows Park (HMP). This individual is a teneral female, as indicated by her terminal appendages and the tenuous appearance of her wings.

No. 1 | 31 MAY 2016 | HMP | Painted Skimmer (teneral female)

Shine on you crazy diamond!

No. 2 | 31 MAY 2016 | HMP | Painted Skimmer (teneral female)

Although Photo No. 1 and 3 look similar, I posted both pictures. Photo No. 1 shows the tenuous appearance of the wings best of all four photos, but I prefer the composition of Photo No. 3. Which one of the two photos do you prefer?

No. 3 | 31 MAY 2016 | HMP | Painted Skimmer (teneral female)

Teneral dragonflies are skittish and prefer to perch in “hidey-holes” that offer protection from predators like paparazzi wildlife photographers. The dragonfly is perching on “soft rush” (Juncus effusus), the common name for the shoreline/emergent plant with light green round stems and brownish flowers that appears in the entire photo set. Soft rush is common in wetland areas.

No. 4 | 31 MAY 2016 | HMP | Painted Skimmer (teneral female)

Painted Skimmer dragonflies do not display sexual dimorphism, that is, adult females and males look similar except for their terminal appendages. Female dragonflies have a pair of cerci (superior appendages) that have little or no function; male dragonflies have three terminal appendages, collectively called “claspers.” The cerci are easy to see in the full-size version of the preceding photo.

Copyright © 2017 Walter Sanford. All rights reserved.

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Wandering Glider dragonfly (male)

December 14, 2016

Wandering Glider dragonfly (Pantala flavescens) was spotted at Mason Neck West Park (MNWP), Fairfax County, Virginia USA. This individual is a male. Wandering Gliders do not display sexual dimorphism; terminal appendages may be used to differentiate females and males.

A Wandering Glider dragonfly (Pantala flavescens) spotted at Mason Neck West Park, Fairfax County, Virginia USA. This individual is a male.

04 OCT 2016 | Mason Neck West Park | Wandering Glider (male)

I like the subtle beauty of the coloration/pattern of markings along the abdomen of Wandering Gliders.

A Wandering Glider dragonfly (Pantala flavescens) spotted at Mason Neck West Park, Fairfax County, Virginia USA. This individual is a male.

04 OCT 2016 | Mason Neck West Park | Wandering Glider (male)

This guy was very skittish! I spooked him when I backed up for a slightly wider view of the scene — usually that happens the other way around.

Copyright © 2016 Walter Sanford. All rights reserved.

Blue-faced Meadowhawk mating frenzy

December 8, 2016

Old Colchester Park and Preserve (OCPP), Fairfax County, Virginia USA is one of a few places in Northern Virginia where Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) is known to occur. OCPP is located near Mason Neck West Park.

More than ten mating pairs of Blue-faced Meadowhawks were spotted at a small vernal pool in the park; the pool was almost completely dry on the day of my visit.

Andromorph females

Some species of dragonflies, such as Blue-faced Meadowhawk, display sexual dimorphism; females are polymorphic for a smaller subset of those species. Andromorph females are male-like in color; heteromorph females are duller in color than males.

Andromorph female Blue-faced Meadowhawk dragonflies, like the ones shown below, are less common than heteromorph females. Andromorphs have a red abdomen with black rings, like male Blue-faced Meadowhawks; unlike males, most female faces are tan and their terminal appendages look different than male appendages.

No. 1

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted at Old Colchester Park and Preserve, Fairfax County, Virginia USA. This pair is "in wheel." The female is an andromorph.

27 SEP 2016 | OCPP | Blue-faced Meadowhawk (mating pair, “in wheel“)

No. 2

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted at Old Colchester Park and Preserve, Fairfax County, Virginia USA. This pair is "in wheel." The female is an andromorph.

27 SEP 2016 | OCPP | Blue-faced Meadowhawk (mating pair, “in wheel“)

No. 3

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted at Old Colchester Park and Preserve, Fairfax County, Virginia USA. This pair is "in wheel." The female is an andromorph.

27 SEP 2016 | OCPP | Blue-faced Meadowhawk (mating pair, “in wheel“)

Heteromorph females

The following photos show heteromorph female Blue-faced Meadowhawk dragonflies. Heteromorphs have a tan abdomen with black rings.

No. 4

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted at Old Colchester Park and Preserve, Fairfax County, Virginia USA. This pair is "in wheel." The female is a heteromorph.

27 SEP 2016 | OCPP | Blue-faced Meadowhawk (mating pair, “in wheel“)

No. 5

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted at Old Colchester Park and Preserve, Fairfax County, Virginia USA. This pair is "in wheel." The female is a heteromorph.

27 SEP 2016 | OCPP | Blue-faced Meadowhawk (mating pair, “in wheel“)

No. 6

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted at Old Colchester Park and Preserve, Fairfax County, Virginia USA. This pair is "in wheel." The female is a heteromorph.

27 SEP 2016 | OCPP | Blue-faced Meadowhawk (mating pair, “in wheel“)

No. 7

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted at Old Colchester Park and Preserve, Fairfax County, Virginia USA. This pair is "in wheel." The female is a heteromorph.

27 SEP 2016 | OCPP | Blue-faced Meadowhawk (mating pair, “in wheel“)

No. 8

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted at Old Colchester Park and Preserve, Fairfax County, Virginia USA. This pair is "in wheel." The female is a heteromorph.

27 SEP 2016 | OCPP | Blue-faced Meadowhawk (mating pair, “in wheel“)

No. 9

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted at Old Colchester Park and Preserve, Fairfax County, Virginia USA. This pair is "in wheel." The female is a heteromorph.

27 SEP 2016 | OCPP | Blue-faced Meadowhawk (mating pair, “in wheel“)

No. 10

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted at Old Colchester Park and Preserve, Fairfax County, Virginia USA. This pair is "in wheel." The female is a heteromorph.

27 SEP 2016 | OCPP | Blue-faced Meadowhawk (mating pair, “in wheel“)

Copyright © 2016 Walter Sanford. All rights reserved.

Time to mate

September 18, 2016

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) was spotted at a vernal pool in Huntley Meadows Park (HMP). The vernal pool, currently dry, is the same one where teneral Blue-faced Meadowhawks were observed during late-May and early-June 2016.

This mating pair is “in wheel.” All dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back: male dragonfly secondary genitalia, called hamules, are located in segments two and three (S2 and S3); female genitalia in segment eight (S8). Dragonflies form the mating wheel in order for their genitalia to connect during copulation.

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is "in wheel." The female is an andromorph.

15 SEP 2016 | HMP | Blue-faced Meadowhawks (mating pair, “in wheel“)

Some species of dragonflies display sexual dimorphism; females are polymorphic for a smaller subset of those species. Andromorph females are male-like in color; heteromorph females are duller in color than males.

Notice the female in this mating pair is an andromorph. Female andromorphs are less common than heteromorphs.

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is "in wheel." The female is an andromorph.

15 SEP 2016 | HMP | Blue-faced Meadowhawks (mating pair, “in wheel“)

Copyright © 2016 Walter Sanford. All rights reserved.

Painted Skimmer dragonflies (females)

February 21, 2016

The following gallery features photos of several Painted Skimmer dragonflies (Libellula semifasciata) spotted on 20 May 2015 near a vernal pool in a remote location in the forest at Huntley Meadows Park.

All of these individuals are females, as indicated by their terminal appendages. For those species of dragonflies that do not display sexual dimorphism, such as Painted Skimmer, males and females are nearly identical in appearance except for their terminal appendages.

Like many species of dragonflies in the Skimmer Family, the Painted Skimmer usually perches on four of six legs, with the two front legs curled around its head.

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

Copyright © 2016 Walter Sanford. All rights reserved.

Is it spring yet?

January 12, 2016

Almost nothing lifts my spirits on a cold winter day quite as much as looking at photos of colorful dragonflies! Like this Painted Skimmer dragonfly (Libellula semifasciata), spotted perching in a meadow alongside Barnyard Run, Huntley Meadows Park.

This individual is a male, as indicated by his terminal appendages. For those species of dragonflies that do not display sexual dimorphism, such as Painted Skimmer, males and females are nearly identical in appearance except for their terminal appendages.

Copyright © 2016 Walter Sanford. All rights reserved.

Slaty Skimmer dragonfly terminal appendages

June 14, 2015

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

Slaty Skimmers display sexual dimorphism. Although mature males and females look different, immature males and females look similar. Terminal appendages may be used to differentiate immature males from females.

A Slaty Skimmer dragonfly (Libellula incesta) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

06 JUN 2015 | Huntley Meadows Park | Slaty Skimmer (female)

Female dragonflies have a pair of cerci (superior appendages) that have little or no function. (See a full-size version of the following image, without annotation.)

A Slaty Skimmer dragonfly (Libellula incesta) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

06 JUN 2015 | Huntley Meadows Park | Slaty Skimmer (female)

Look closely at the full-size version of the preceding annotated image. Female Slaty 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 male Slaty Skimmers and immature/adult female Slaty Skimmers are nearly identical in appearance except for their terminal appendages. (See a full-size version of the following image, without annotation.)

A Slaty Skimmer dragonfly (Libellula incesta) spotted at Little Hunting Creek, Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an immature male.

07 JUL 2014 | Huntley Meadows Park | Slaty Skimmer (immature male)

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”). (See a full-size version of the following image, without annotation.)

A Slaty Skimmer dragonfly (Libellula incesta) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a young male with a slightly malformed wing.

06 JUN 2015 | Huntley Meadows Park | Slaty Skimmer (young male)

This individual is a young male, as indicated by the blue-black partial pruinescence covering his body. He has a slightly malformed wing that is more noticeable in the preceding side view and less noticeable in the following dorsal view.

A Slaty Skimmer dragonfly (Libellula incesta) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a young male with a slightly malformed wing.

06 JUN 2015 | Huntley Meadows Park | Slaty Skimmer (young male)

Black pruinescence that completely covers the body of following mature male Slaty Skimmer makes it look quite different from the immature male (shown above), other than its terminal appendages.

A Slaty Skimmer dragonfly (Libellula incesta) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a mature male.

10 SEP 2014 | Huntley Meadows Park | Slaty Skimmer (mature male)

Digital scans by G & J Strickland:

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

  • Genus Libellula | Libellula incesta | Slaty Skimmer | male | top view
  • Genus Libellula | Libellula incesta | Slaty Skimmer | male | side view

Related Resources: Odonate Terminal Appendages.

Copyright © 2015 Walter Sanford. All rights reserved.

Spangled Skimmer dragonfly terminal appendages

June 10, 2015

Spangled Skimmer (Libellula cyanea) 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).

Spangled Skimmers display sexual dimorphism. Although mature males and females look different, immature males and females look similar. Terminal appendages may be used to differentiate immature males from females.

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

A Spangled Skimmer dragonfly (Libellula cyanea) spotted  at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

22 MAY 2015 | HMP | Spangled Skimmer (female)

Look closely at the full-size version of the following annotated image. Female Spangled Skimmers have two 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.

Another useful field marker that may be used to differentiate males from females: females have broad dark wing tips; males, not so much.

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”).

A Spangled Skimmer dragonfly (Libellula cyanea) spotted  at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an immature male.

22 MAY 2015 | HMP | Spangled Skimmer (immature male)

Blue pruinescence that covers the body of following mature male Spangled Skimmer makes it look quite different from the immature male (shown above), other than its terminal appendages and distinctive black-and-white pterostigmata.

A Spangled Skimmer dragonfly (Libellula cyanea) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male.

26 JUN 2012 | HMP | Spangled Skimmer (mature male)

Related Resources: Odonate Terminal Appendages.

Copyright © 2015 Walter Sanford. All rights reserved.

Twelve-spotted Skimmer dragonfly terminal appendages

May 31, 2015

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”).

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.

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

Related Resources: Odonate Terminal Appendages.

Copyright © 2015 Walter Sanford. All rights reserved.

Twelve-spotted Skimmer dragonfly (young male)

May 29, 2015

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.

A Twelve-spotted Skimmer dragonfly (Libellula pulchella) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a young male.

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 marker for identification of Twelve-spotted Skimmer males and females, in addition to differences in their terminal appendages.

A Twelve-spotted Skimmer dragonfly (Libellula pulchella) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a young male.

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.


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