Posts Tagged ‘claspers’

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.)

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.

More Big Bluet damselflies

December 24, 2016

More Big Bluet damselflies (Enallagma durum) were spotted in July 2016 during two photowalks along the Potomac River at Dyke Marsh Wildlife Preserve (DMWP).

More males

These individuals are males, as indicated by their blue and black coloration and by their terminal appendages.

Mating pair

The mating pair of Big Bluet damselflies shown in the following photograph is “in wheel,” in which the male uses “claspers” (terminal appendages) at the end of his abdomen to hold the female by her neck/thorax while they are joined at their abdomens. The male, blue and black in color, is on top; the female, green and black in color, is on the bottom.

The copulatory, or wheel, position is unique to the Odonata, as is the distant separation of the male’s genital opening and copulatory organs. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 377-378). Princeton University Press. Kindle Edition.

The wheel position is sometimes referred to as “in heart” when damselflies mate. In this case, the heart shape is deformed slightly.

A mating pair of Big Bluet damselflies (Enallagma durum) spotted at Dyke Marsh Wildlife Preserve, Fairfax County, Virginia USA. This pair is "in heart."

19 JUL 2016 | DMWP | Big Bluet (mating pair, “in tandem”)

The same pair is “in tandem” a while later: the male is on the right; the female is on the left. The male is engaged in “contact guarding,” in which the male and female fly “in tandem” to egg-laying sites. Contact guarding is used by some species of odonates to prevent aggressive males from hijacking the female.

A mating pair of Big Bluet damselflies (Enallagma durum) spotted at Dyke Marsh Wildlife Preserve, Fairfax County, Virginia USA. This pair is "in tandem."

19 JUL 2016 | DMWP | Big Bluet (mating pair, “in tandem”)

Look closely at the underside of the female’s abdomen, near the tip. Notice the ovipositor that she uses to insert eggs into vegetation (endophytic oviposition).

It’s helpful to take photos of mating pairs of damselflies, especially “in tandem,” since males and females of the same species can look quite different.

Sidebar: Scientific Classification of Damselflies

The following concise explanation of the scientific classification of damselflies is provided to help the reader understand where the genus Enallagma (American Bluets) fits into the bigger picture of the Order OdonataSuborder Zygoptera (Damselflies).

There are five families of damselflies in the United States of America, although only three families occur in the mid-Atlantic USA: Broad-winged damselflies; Narrow-winged damselflies (a.k.a., Pond Damselflies); and Spreadwing damselflies.

Family Calopterygidae is comprised of two genera.

Family Coenagrionidae is comprised of 14 genera. Three genera are common in Northern Virginia: Argia (Dancers); Enallagma (American Bluets); and Ischnura (Forktails).

Family Lestidae is comprised of two genera.

  • Archilestes (e.g., Great Spreadwing)
  • Lestes (e.g., Slender Spreadwing, Southern Spreadwing, Swamp Spreadwing)

There are relatively few genera of Broad-winged Damselflies and Spreadwing Damselflies. In contrast, there are many more genera and species of Narrow-winged Damselflies — more species, including many that look similar, makes this family the most challenging to learn!

Related Resources: Excellent digital scans created by Gayle and Jeanelle Strickland. Click on the button labeled “Download file” in order to view full-size version of the graphics.

  • Enallagma durum male #4 | male | JPG
  • Enallagma durum female #2 | female | JPG

Copyright © 2016 Walter Sanford. All rights reserved.

Great Spreadwing damselfly (male, eating)

December 18, 2016

Great Spreadwing damselfly (Archilestes grandis) was spotted in the forest near a vernal pool at Huntley Meadows Park. This individual is a male, as indicated by his deep blue eyes, familiar yellow racing stripe on the side of its thorax, bluish-white coloration on abdominal segments 9-10 (S9-10), and distinctive terminal appendages (claspers).

While I was sitting on my Coleman camp stool watching the male damselfly, suddenly he flew up and around head and landed near the same spot where he had been perching. I know from experience this type of behavior suggests the damselfly probably grabbed something to eat.

The following brief time-series of photos shows the damselfly eating an unknown species of winged insect.

11:19:52 a.m. EST

11:19:58 a.m. EST

11:20:14 a.m. EST

Editor’s Note: If you check the EXIF for all three photos, then you will see the time stamp is one hour later than the times shown above. 06 November was the first time I used my camera since the end of Daylight Saving Time (at 2:00 a.m. the same day) — I forgot to reset the time in-camera!

Copyright © 2016 Walter Sanford. All rights reserved.


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