Ebony Jewelwing damselfly (male)

July 30, 2021

An Ebony Jewelwing damselfly (Calopteryx maculata) was spotted along a small stream located in Occoquan Regional Park, Fairfax County, Virginia USA.

05 JUN 2021 | Fairfax County, VA | Ebony Jewelwing (male)

This individual is a male, as indicated by his all black wings and terminal appendages.

05 JUN 2021 | Fairfax County, VA | Ebony Jewelwing (male)

Habitat

It’s easy to find Ebony Jewelwing. Look for a small stream in the forest.

Slow-flowing woodland streams, usually associated with herbaceous vegetation. Tend to be more at rapids when that habitat is present. Occur on open banks when trees nearby (trees essential for roosting at night). May be abundant at small streams in woods where very few other species are present. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 1249-1251). Princeton University Press. Kindle Edition.

Copyright © 2021 Walter Sanford. All rights reserved.

Post update: Stylurus sp. exuvia

July 27, 2021

Three years ago I had the honor and pleasure of helping Michael Boatwright, my good friend and odonate hunting buddy, identify an interesting exuvia that he collected on 13 July 2018 at an undisclosed location in Amherst County, Virginia USA.

After working through several dichotomous keys for the identification of odonate larvae/exuviae, Mike and I determined the specimen is most likely from Zebra Clubtail (Stylurus scudderi). Zebra Clubtail is extremely rare in the state of Virginia.

The following annotated image shows a dorsal view of the exuvia.

13 JUL 2018 | Amherst County, VA USA | Stylurus scudderi (exuvia)

The best way to confirm our tentative identification of the exuvia is to find adult Zebra Clubtail at the same location. Easier said than done! During the next few years, Mike found more exuviae but no adults.

On 22 July 2021, years of searching the site finally came to fruition when Mike discovered a teneral female Zebra Clubtail, shown below.

Photo used with written permission from Mike Boatwright.

Look closely at the full-size version of the preceding photo. Notice the teneral dragonfly is perched on the exuvia from which it emerged. Mike collected the exuvia after the dragonfly flew high into the tree canopy, so now we have the type specimen for verification of other exuviae.

Persistence pays

Sincere congratulations, Mike! You never gave up when it would have been the easier thing to do.

Related Resources

  • Stylurus sp. exuvia – a blog post by Walter Sanford providing a detailed account of the process used to determine the identity of the specimen collected by Mike on 13 July 2018.
  • Mike’s post in the Virginia Odonata Facebook group announcing his discovery on 22 July 2021. Mike is the founder and administrator of Virginia Odonata.

Copyright © 2021 Walter Sanford. All rights reserved.

More Bar-winged Skimmers (males)

July 23, 2021

At least two male Bar-winged Skimmer dragonflies (Libellula axilena) were spotted along the shoreline of a small pond at an undisclosed location in Prince William County, Virginia USA.

It’s possible all of the photos featured in this blog post are of the same mature male that is featured in another recent post, as indicated by a distinctive pattern of spider web strands on the wings of the dragonfly.

Look closely along the leading edge of the wings. Notice the dark bars from which the common name for this species is derived are almost invisible.

17 JUN 2021 | PNC. Wm. County |  Bar-winged Skimmer (mature male)

17 JUN 2021 | PNC. Wm. County |  Bar-winged Skimmer (mature male)

17 JUN 2021 | PNC. Wm. County |  Bar-winged Skimmer (mature male)

17 JUN 2021 | PNC. Wm. County |  Bar-winged Skimmer (mature male)

For what it’s worth, the first and last photos in this set are my favorite.

Related Resource: Bar-winged Skimmer dragonfly (male).

Copyright © 2021 Walter Sanford. All rights reserved.

Variable Dancer damselfly (male)

July 20, 2021

A Variable Dancer damselfly (Argia fumipennis) was spotted near a small pond at an undisclosed location in Prince William County, Virginia USA.

17 JUN 2021 | Prince William County | Variable Dancer (male)

This individual is a male, as indicated by his mostly purple coloration.

Variable Dancer is a habitat generalist that can be found almost anywhere there is water. Mature males are easy to recognize due to their unique coloration — there are no other species of violet damselflies found in the eastern one-third of the United States. Female Variable Dancers, like many female odonates, are more challenging to identify than males.

It’s helpful to get shots of mating pairs of damselflies, especially “in tandem,” since males and females of the same species can look quite different. The excellent high-resolution digital scans by Gayle and Jeanelle Strickland, listed under “Related Resources” (below), provide clear views of male and female Variable Dancer damselflies.

Related Resources: High-resolution digital scans created by Gayle and Jeanelle Strickland.

Sidebar: Scientific Classification of Damselflies

The taxonomic classification of Variable Dancer is as follows: Order Odonata (Dragonflies and Damselflies); Suborder Zygoptera (Damselflies); Family Coenagrionidae (Narrow-winged Damselflies); Genus Argia (Dancers); Subspecies Argia fumipennis violacea (Violet Dancer).

The following concise explanation of the scientific classification of damselflies is provided to help the reader understand where Argia (Dancers) fit into the bigger picture of the Order Odonata, Suborder Zygoptera (Damselflies).

There are four 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!

Editor’s Note: Please comment to let me know whether the preceding information is helpful.

Copyright © 2021 Walter Sanford. All rights reserved.

Zebra Swallowtail butterfly

July 16, 2021

Zebra Swallowtail butterfly (Eurytides marcellusProtographium marcellus) was spotted near a small pond at an undisclosed location in Prince William County, Virginia USA.

17 JUN 2021 | Prince William County | Zebra Swallowtail

Notice the Zebra Swallowtail lost part of one of its tails, possibly the result of a close encounter with predator.

Copyright © 2021 Walter Sanford. All rights reserved.

Gray Petaltail dragonfly (male)

July 13, 2021

A Gray Petaltail dragonfly (Tachopteryx thoreyi) was observed during a photowalk with Michael Powell along the shoreline of a small pond at an undisclosed location in Prince William County, Virginia USA.

Mike spotted the Gray Petaltail first, when we were on opposite sides of the pond. Mike was able to shoot a few photos before the dragonfly flew away and Mike moved on. I thought Mike gave up on the subject too quickly so I decided to use one of my tried and true strategies for finding and photographing odonates: Sit in a good spot and wait for the game to come to me.

I walked around to the other side of the pond and sat down on my small, lightweight camp stool about 12-15 feet from the place where Mike had seen the Gray Petaltail. Sure enough, the dragonfly returned to the same perch soon afterward!

The first photo is the “record shot,” that is, get a shot, any shot.

17 JUN 2021 | PNC. Wm. County | Gray Petaltail (male)

This individual is a male, as indicated by his “indented” hind wings and terminal appendages.

17 JUN 2021 | PNC. Wm. County | Gray Petaltail (male)

The dragonfly would perch briefly, then fly away.

17 JUN 2021 | PNC. Wm. County | Gray Petaltail (male)

The male dragonfly did the same thing repeatedly, always returning to a slightly different perch each time. Turns out he was hunting for food.

17 JUN 2021 | PNC. Wm. County | Gray Petaltail (male)

I would describe T. thoreyi as an “ambush predator” — sometimes Gray Petaltail hunts for prey by waiting for other flying insects to pass by and ambushing them aerially when they do. Like the crane fly shown below that the Gray grabbed before landing on my bucket hat.

Photo used with written permission from Michael Powell.

I was happy to provide a white table cloth for a classy dining experience with one of my favorite species of dragonflies.

Habitat

For habitat-specific odonates such as T. thoreyi, it’s all about location, location, location. “Gray Petaltail dragonfly (male)” is another blog post by Walter Sanford that provides actionable intel regarding ideal habitat for Grays.

Range map

The following map shows all official records for Tachopteryx thoreyi in the United States of America. Gray Petaltail is a habitat specialist that is challenging to find.

Related Resources

  • Tachopteryx thoreyi Gray Petaltail on NatureServe Explorer. The conservation status for T. thoreyi in Virginia is “Apparently Secure (S4).” That’s good news. The bad news: That doesn’t mean it’s easy to find.
  • Gray Petaltail dragonfly (male)” – another blog post by Walter Sanford that provides actionable intel regarding ideal habitat for Grays.

Copyright © 2021 Walter Sanford. All rights reserved.

Bar-winged Skimmer dragonfly (male)

July 9, 2021

A Bar-winged Skimmer dragonfly (Libellula axilena) was spotted along the shoreline of a small pond at an undisclosed location in Prince William County, Virginia USA.

This individual is a mature male, as indicated by his coloration and terminal appendages.

17 JUN 2021 | PNC. Wm. County |  Bar-winged Skimmer (mature male)

This mature male has mated many times, as indicated by the scratches on the light-blue pruinescence covering his abdomen.

Males that have mated often have marks on their abdomen where the female legs have scratched them. This is especially obvious in species in which males develop pruinosity, as the pruinosity on the mid-abdomen is scratched off, and the signs are visible at some distance. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 390-392). Princeton University Press. Kindle Edition.

The next photo is full-frame (4,000 x 3,000 pixels), that is, uncropped.

17 JUN 2021 | PNC. Wm. County |  Bar-winged Skimmer (mature male)

Look closely along the leading edge of this individual’s wings. Notice the dark bars from which the common name for this species is derived are almost invisible.

Habitat

According to Dr. Steve Roble’s excellent datasets for the Commonwealth of Virginia, the adult flight period for Bar-winged Skimmer is from May 08 to September 28. Dr. Roble describes its habitat as “ponds.”

“Ponds” is perhaps too simple a descriptor for the habitat preferred by Bar-winged Skimmer, otherwise L. axilena should be more common than a map of its range suggests. Dennis Paulson provides a little more specificity.

Habitat: Wooded slow streams and sloughs, forest pools. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Location 9152). Princeton University Press. Kindle Edition.

Kevin Munroe, former manager at Huntley Meadows Park, provides the best description of Bar-winged Skimmer habitat that I’ve seen.

One of our less common skimmers, this dragonfly has relatively specific habitat needs. It prefers very shallow marshy pools in the full sun. If there’s enough water for fish, it’s too deep for Bar-winged Skimmers. And of course shallow pools in the full sun tend to quickly evaporate and dry up, so stable populations in Northern Va. are few and far between. The similar Great Blue Skimmer also likes shallow water, but is much more common. One reason being that they can handle partly shady forest pools and forest swamps, both too dark for Bar-wings. Source Credit: Bar-winged Skimmer, by Kevin Munroe.

I have observed Bar-winged Skimmer dragonflies at two locations in Huntley Meadows Park that provided habitat similar to Kevin’s recipe. Bar-winged Skimmer is no longer found at either place.

I have seen Bar-winged Skimmer at Sundew Bog, located in the Central Tract at Patuxent Research Refuge.

The Central Tract of the refuge is closed to public visitation due to the sensitive nature of much of the scientific work. Source Credit: Patuxent Research Refuge brochure.

Range map

Not all species of Skimmers are as common as I tend to think. For example, the following map shows all official records for Libellula axilena in the United States of America. As you can see, Bar-winged Skimmer is a relatively uncommon species of odonate.

What are the take-aways?

Many species of dragonflies in the Family Libellulidae (Skimmers) are habitat generalists and relatively easy to find almost anywhere there is water. In contrast, I think it’s fair to say Bar-winged Skimmer is a habitat specialist that is challenging to find.

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

Post update: What is it?

July 6, 2021

I spotted an odonate exuvia along the shoreline of a small pond at an undisclosed location in Prince William County, Virginia USA that was collected by Mike Powell, my good friend and photowalking buddy.

This specimen is from the Family Aeshnidae (Darners), as indicated by the following field marks: the exuvia has a flat labium that doesn’t cover the face (not mask-like); the antennae are thin and thread-like (not club-like, as in Gomphidae larvae/exuviae); and the eyes are large relative to the size of the head.

17 JUN 2021 | PNC. Wm. County | Anax junius exuvia

Lateral spines along abdominal segments seven, eight, and nine (S7-9) indicate the genus is Anax; the length of the exuvia indicates junius (greater than ~4 cm, as is).

Common Green Darner dragonfly (Anax junius) is one of the more common species of Aeshnidae found in Northern Virginia.

Related Resource: What is it?

Copyright © 2021 Walter Sanford. All rights reserved.

Common Sanddragon dragonflies (males)

July 2, 2021

Two Common Sanddragon dragonflies (Progomphus obscurus) were spotted along a mid-size stream at an undisclosed location in Prince William County, Virginia USA.

Both individuals are male, as indicated by their terminal appendages and “indented” hind wings.

Male No. 1

I spotted a Common Rockdragon while searching for Eastern Least Clubtail (Stylogomphus albistylus). OK, OK, there is no species of dragonfly called “Common Rockdragon.” My point is simply this: Common Sanddragon is typically found perching on sand rather than rocks. Any perch in a storm I guess.

17 JUN 2021 | PNC. Wm. County | Common Sanddragon (male)

Anyway, this guy was super skittish — I got one shot before he flew away. I waited a while for him to return. No luck. So I moved on.

Male No. 2

I stopped to rest at a sandy bank (located farther upstream from the first location)  where I have seen/photographed Common Sanddragon in the past. Sure enough, a male Common Sanddragon landed on the beach soon after I sat down on my camp stool.

The first photo is cropped for better composition.

17 JUN 2021 | PNC. Wm. County | Common Sanddragon (male)

He took flight several times but always returned to the same place. I speculate he was actively hunting insects flying over the stream.

The next two photos are full-frame (4,000 x 3,000 pixels), that is, uncropped.

17 JUN 2021 | PNC. Wm. County | Common Sanddragon (male)

The male’s “indented” hind wings (see “Related Resource”) are shown clearly in the full-size versions of these photos.

17 JUN 2021 | PNC. Wm. County | Common Sanddragon (male)

Related Resource

Ed Lam, author and illustrator of Damselflies of the Northeast, created the following composite image that shows how to differentiate male and female Common Sanddragons. Notice the difference in the shape of male and female hind wings: male hind wings are “indented” near the body; female hind wings are rounded.

Ed-Lam_Common-Sanddragon_male-female

Copyright © 2021 Walter Sanford. All rights reserved.

Unicorn Clubtail dragonfly (male)

June 29, 2021

A Unicorn Clubtail dragonfly (Arigomphus villosipes) was photographed near the shoreline of a small pond at an undisclosed location in Fairfax County, Virginia USA.

This individual is a male, as indicated by his 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”).

For those of you keeping score at home, notice male Unicorn terminal appendages have four points/prongs. Does that mean A. villosipes is an exception to the rule of three terminal appendages for male dragonflies? In a word, no.

05 JUN 2021 | Fairfax County, VA | Unicorn Clubtail (male)

The preceding photo shows a clear view of the male’s terminal appendages. Zoom-in on the full-size version of the photo and you should notice that the epiproct for Unicorn Clubtail is essentially a wide plate with two points/prongs.

Related Resource: Odonate Terminal Appendages – a permanent reference page in my blog featuring identification guides for most of the common species of odonates found in Virginia, and even some of the uncommon to rare species.

Copyright © 2021 Walter Sanford. All rights reserved.

 


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