Posts Tagged ‘claspers’

Black Saddlebags (terminal appendages)

September 15, 2017

Male and female Black Saddlebags dragonflies (Tramea lacerata) are somewhat similar in appearance. Terminal appendages can be used to identify gender.

Female

A female Black Saddlebags was spotted along Deephole Point Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

10 SEP 2017 | Occoquan Bay NWR | Black Saddlebags (female)

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

10 SEP 2017 | Occoquan Bay NWR | Black Saddlebags (female)

(See a full-size version of the original photo, without annotation.)

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”).

A male Black Saddlebags was spotted in the central wetland area at Huntley Meadows Park, Fairfax County, Virginia USA.

12 SEP 2014 | Huntley Meadows Park | Black Saddlebags (male)

(See a full-size version of the original photo, without annotation.)

Copyright © 2017 Walter Sanford. All rights reserved.

Advertisements

Springtime Darner (terminal appendages)

September 11, 2017

Male and female Springtime Darner dragonflies (Basiaeschna janata) are colored similarly sometimes. Terminal appendages can be used to identify gender.

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”).

A male Springtime Darner was spotted along a mid-size rocky stream located at Hemlock Overlook Regional Park (HORP), Fairfax County, Virginia USA.

(See a full-size version of the original photo, without annotation.)

Female

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

Female Springtime Darners are polymorphic: the spots on their abdomen are either blue (andromorphic) or green (heteromorphic); this female — spotted at a remote location in Huntley Meadows Park (HMP) — is a blue andromorph.

15 APR 2016 | HMP | Springtime Darner (female, blue andromorph)

(See a full-size version of the original photo, without annotation.)

Copyright © 2017 Walter Sanford. All rights reserved.

Russet-tipped Clubtail (terminal appendages)

August 14, 2017

Male Russet-tipped Clubtail dragonflies (Stylurus plagiatus) have a larger, more colorful club than females of the same species, their hind wings are “indented,” and their terminal appendages are shaped differently. Compare and contrast the appearance of males and females by looking at the following annotated images.

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”).

14 OCT 2016 | JMAWR | Russet-tipped Clubtail (male)

(See a full-size version of the original photo, without annotation.)

Notice the epiproct is a wide “plate” that spans both cerci, as shown in the full-size version of the preceding annotated image.

Female

All female dragonflies have a pair of cerci (superior appendages) that have little or no function. The hind wings of female clubtails are rounded.

21 AUG 2015 | Powhatan County, VA | Russet-tipped Clubtail (female)

(See a full-size version of the original photo, without annotation.)

The female Russet-tipped Clubtail dragonfly shown in the preceding image was spotted along the James River by my good friend Michael Boatwright, founder of the Virginia Odonata Facebook group. Sincere thanks to Mike for permission to use his photographs (background and inset).

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

  • Genus Stylurus | Stylurus plagiatus | Russet-tipped Clubtail | male | top view
  • Genus Stylurus | Stylurus plagiatus | Russet-tipped Clubtail | female | top view
  • Genus Stylurus | Stylurus plagiatus | Russet-tipped Clubtail | female | side view

Copyright © 2017 Walter Sanford. All rights reserved.

Mocha Emerald dragonfly claspers

July 13, 2017

Mocha Emerald dragonfly (Somatochlora linearis) was spotted along a small creek at a remote location in the forest at Huntley Meadows Park. This individual is a male, as indicated by his terminal appendages and hamules.

All 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”).

09 JUL 2017 | Huntley Meadows Park | Mocha Emerald (male)

(See a full-size version of the original photo, without annotation.)

09 JUL 2017 | Huntley Meadows Park | Mocha Emerald (male)

(See a full-size version of the original photo, without annotation.)

Male dragonfly secondary genitalia, called hamules, are located below abdominal segments two and three (S2 and S3), as shown in the following annotated image. Hamules come in a variety of sizes and shapes, but their function is identical for all species of odonates.

hamules: paired structures that project from genital pocket under second segment and hold female abdomen in place during copulation Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 11618-116198). Princeton University Press. Kindle Edition.

09 JUL 2017 | Huntley Meadows Park | Mocha Emerald (male)

(See a full-size version of the original photo, without annotation.)

Related Resource: Mocha Emerald terminal appendages (female).

Technique Hint: Did you notice that the “focus” of each photo (not to be confused with the focus point) is shown against a lighter background? That’s no accident — I composed each shot that way. As a result, the terminal appendages (cerci and epiproct) are much easier to see in the first two photos than the last shot, in which the composition highlights the hamules.

Copyright © 2017 Walter Sanford. All rights reserved.

Calico making the case for claspers

June 27, 2017

A Calico Pennant dragonfly (Celithemis elisa) was spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge (OBNWR), Prince William County, Virginia USA.

Mature adult female Calico Pennants are yellow; mature adult male Calico Pennants are red. So the following individual must be female, right? Wrong!

20 JUN 2017 | OBNWR | Calico Pennant (immature male)

This individual is an immature male, as indicated by his terminal appendages and yellow coloration.

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”).

20 JUN 2017 | OBNWR | Calico Pennant (immature male)

(See a full-size version of the original photo, without annotation.)

In contrast, female dragonflies have a pair of cerci (superior appendages) that have little or no function.

20 JUN 2017 | OBNWR | Calico Pennant (female)

(See a full-size version of the original photo, without annotation.)

Color can be a deceptive field marker. Immature males appear similar to immature females of the same species (and some mature females) for many types of dragonflies that display sexual dimorphism. This is true for many members of Family Libellulidae (Skimmers), such as Calico Pennant. Terminal appendages may be used to differentiate gender for many species of dragonflies.

20 JUN 2017 | OBNWR | Calico Pennant (immature male)

Related Resource: Odonate Terminal Appendages — single-topic field guides for dragonflies and damselflies featuring both text and annotated photos.

Copyright © 2017 Walter Sanford. All rights reserved.

Common Baskettail (terminal appendages)

May 18, 2017

A male and female Common Baskettail dragonfly (Epitheca cynosura) were spotted recently at the same location in Fairfax County, Virginia USA.

Male and female Common Baskettails look similar. Terminal appendages can be used to identify gender.

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”).

03 MAY 2017 | Fairfax County, VA | Common Baskettail (male)

(See a full-size version of the original photo, without annotation.)

Female

Female dragonflies have a pair of cerci (superior appendages) that have little or no function. The abdomen of female Common Baskettails is noticeably thicker than males of the same species.

03 MAY 2017 | Fairfax County, VA | Common Baskettail (female)

(See a full-size version of the original photo, without annotation.)

A better view of the subgenital plate is provided by the following digital scan of the underside of the abdomen of a female Common Baskettail. The subgenital plate looks a little like a pair of calipers. Also known as vulvar lamina, the subgenital plate is located under the ninth abdominal segment (S9) of some female odonates and “serves to hold eggs in place during exophytic oviposition.” Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.

Image used with permission from Ed Lam.

Copyright © 2017 Walter Sanford. All rights reserved.

Spine-crowned Clubtail (terminal appendages)

May 10, 2017

A male and female Spine-crowned Clubtail dragonfly (Hylogomphus abbreviatus) were spotted recently in Fairfax County, Virginia USA.

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”). The epiproct for Spine-crowned Clubtail is essentially a wide plate with two prongs.

03 MAY 2017 | Fairfax County, VA | Spine-crowned Clubtail (male)

(See a full-size version of the original photo, without annotation.)

The hind wings of male clubtail dragonflies are “indented” near the body, as shown in the preceding photograph. In contrast, the hind wings of female clubtails are rounded (shown below). Also notice the right hind wing of the male is slightly malformed.

Female

Female dragonflies have a pair of cerci (superior appendages) that have little or no function. The abdomen of female Spine-crowned Clubtails is noticeably thicker than males of the same species.

03 MAY 2017 | Fairfax County, VA | Spine-crowned Clubtail (female)

(See a full-size version of the original photo, without annotation.)

Copyright © 2017 Walter Sanford. All rights reserved.

Ashy Clubtail dragonfly (male)

April 28, 2017

An Ashy Clubtail dragonfly (Phanogomphus lividus) was spotted during a photowalk at Riverbend Park, Fairfax County, Virginia USA. This individual is a male, as indicated by his indented hind wings and terminal appendages.

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”).

Notice the epiproct is a large “plate” that spans both cerci, as shown in the full-size version of the following photo.

One thing you can count on when photographing Ashy Clubtails (well, usually) is the subject will be perching on a chaotic background that is difficult to crop without creating leading lines that mislead the viewer’s eye and distracting elements near the edges of the image.

Copyright © 2017 Walter Sanford. All rights reserved.

Phanogomphus

April 20, 2017

Two teneral dragonflies were observed near Mulligan Pond during a photowalk at Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. I was able to photograph the first one I spotted; the second flew away as soon as I approached it.

This dragonfly is either Ashy Clubtail (Phanogomphus lividus) or Lancet Clubtail (Phanogomphus exilis). Based upon the short, faded yellow markings on the dorsal side of abdominal segments eight and nine (S8-9), this individual is probably an Ashy Clubtail dragonfly. Less reliably, the 18 April date of the spotting also suggests Ashy Clubtail (for Northern Virginia).

18 APR 2017 | JMAWR | Ashy Clubtail or Lancet Clubtail (female)

Both Ashy- and Lancet Clubtail dragonflies were formerly classified as members of the genus Gomphus. Both species were reclassified recently as Phanogomphus. In the world of taxonomic classification, there are “lumpers” and “splitters.” Score one for the splitters!

Notice the first photo shows the wings folded above the abdomen. I spotted the teneral dragonfly when it flew toward me from the pond shoreline. The dragonfly rested in this location for a few minutes before it flew to a new spot (shown below) where it perched briefly with its wings unfolded. The last time I saw the dragonfly, it was flying toward the forest alongside the pond.

The other teneral dragonfly that I saw — “the one that got away” — was perched on the lawn near the walking path around the lake; it flew toward the forest when I moved closer to take some photographs.

18 APR 2017 | JMAWR | Ashy Clubtail or Lancet Clubtail (female)

(See a full-size version of the original photo, without annotation.)

This specimen is a female, as indicated by her rounded hind wings and terminal appendages.

All female dragonflies have two cerci (superior appendages); in contrast all male dragonflies have two cerci and one epiproct (inferior appendage), collectively called “claspers.” Contrast the appearance of the terminal appendages of this female Ashy Clubtail with a male of the same species.

The last photo in the set is a wider view that shows how well-camouflaged the dragonfly was perched on the lawn around the pond.

18 APR 2017 | JMAWR | Ashy Clubtail or Lancet Clubtail (female)

The Backstory

I was surprised to discover a Lancet Clubtail dragonfly near Mulligan Pond during late-June 2016. Knowing that Ashy Clubtails can be found in the same habitats preferred by Lancet Clubtails, I decided to look for Ashy Clubtails at Jackson Miles Abbott Wetland Refuge beginning in mid-April 2017. Apparently Mulligan Pond is a good place for both species, because I spotted two Ashy Clubtails the first time I went looking for them. Ah, if only odonate hunting were always so easy!

Post Update

As far as I know, this is the first record for this species at this location. A new record for Ashy Clubtail (Phanogomphus lividus) at Jackson Miles Abbott Wetland Refuge was submitted to the Odonata Central records database on 22 April 2017.

Copyright © 2017 Walter Sanford. All rights reserved.

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.


%d bloggers like this: