Posts Tagged ‘male’

Twin-spotted versus Brown Spiketails

February 8, 2022

Four species of genus Cordulegaster are found in the Commonwealth of Virginia: Brown Spiketail (C. bilineata); Tiger Spiketail (C. erronea); Twin-spotted Spiketail (C. maculata); and Arrowhead Spiketail (C. obliqua).

According to the excellent datasets for the Commonwealth of Virginia by Dr. Steve Roble, Staff Zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage, the adult flight periods for spiketail dragonflies are as follows.

MAR 16 – JUL 10 = Twin-spotted

MAR 28 – AUG 08 = Brown

MAY 11 – JUL 17 = Arrowhead

MAY 28 – AUG 22 = Tiger

As you can see, there’s a lot of overlap between the flight periods for Twin-spotted Spiketail and Brown Spiketail. Also notice the overlap between the flight periods for Arrowhead Spiketail and Tiger Spiketail.

I think we can agree the distinctive arrowhead-shaped yellow markings on the abdomen of Arrowhead Spiketail (shown below) are unmistakeable for any other species of spiketail, including Tiger Spiketail.

07 JUL 2014 | Fairfax County, VA | Arrowhead Spiketail (male)

In the opinion of the author it’s more likely a dark-colored Brown Spiketail, such as the one shown below, might be misidentified as a Twin-spotted Spiketail.

02 MAY 2019 | Fairfax County, VA | Brown Spiketail (male)

Differentiating Twin-spotted versus Brown

Twin-spotted and Brown Spiketail dragonflies can be differentiated by looking closely at the yellow markings on abdominal segments one through three (S1-S3).

07 MAY 2018 | Fairfax County, VA | Twin-spotted Spiketail (male)

The pattern of yellow markings on S1-S3 is simpler for Twin-spotted than Brown, as you can see by looking at the full-size versions of these two photos, shown above and below.

11 MAY 2018 | Fairfax County, VA | Brown Spiketail (male)

Female Twin-spotted versus Brown

Female Twin-spotted Spiketails, such as the one shown below, have a much longer subgenital plate (ovipositor) than female Brown Spiketails.

Photo used with written permission from Mike Boatwright.

The subgenital plate for the following female Brown Spiketail is barely visible.

09 MAY 2013 | Fairfax County, VA | Brown Spiketail (female)

It isn’t a lot easier to see the subgenital plate in a close-up view of the same individual shown above.

09 MAY 2013 | Fairfax County, VA | Brown Spiketail (female)

Coach’s Corner

Thanks to Mike Boatwright, founder and administrator of the Virginia Odonata Facebook group, for coaching me up on how to differentiate Twin-spotted Spiketail from Brown Spiketail, including both males and females.

Look for yellow markings on the side of abdominal segments one through three (S1-S3): green arrows show the lack of yellow markings on S1-S3 for Twin-spotted; red arrows show yellow markings on the sides of S1-S3 for Brown.

Set 1

Twin-spotted Spiketail | male (dorsal view)

Photo used with written permission from Mike Boatwright.

Brown Spiketail | male (dorsal view)

Photo used with written permission from Mike Boatwright.

Set 2

Twin-spotted Spiketail | male (dorso-lateral view)

Photo used with written permission from Mike Boatwright.

Brown Spiketail | male (dorso-lateral view)

Photo used with written permission from Mike Boatwright.

What are the take-aways?

Remember the odonate hunter’s credo: Shoot first (photographs, that is); ask questions later. (Repeat it like a mantra.) Get a shot, any shot; refine the shot gradually.

Please don’t waste precious time in the field! You can study the photos when you return home in order to identify the subject(s) you shot as either Twin-spotted Spiketail or Brown Spiketail.

Copyright © 2022 Walter Sanford. All rights reserved.

Twin-spotted Spiketail (terminal appendages)

January 25, 2022

Male

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”).

Male members of the Family Cordulegastridae (Spiketails), including male Twin-spotted Spiketail dragonflies (Cordulegaster maculata), have relatively small cerci (terminal appendages) that can be mistaken for female cerci.

07 MAY 2018 | Fairfax County, VA | Twin-spotted Spiketail (male)

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.

07 MAY 2018 | Fairfax County, VA | Twin-spotted Spiketail (male)

Female

As far as I know I have never seen a female Twin-Spotted Spiketail. (I have seen several individuals that I was unable to photograph.) No problem. Mike Boatwright kindly allowed me to annotate a couple of his photographs.

Photo used with written permission from Mike Boatwright.

These individuals are female, as indicated by their rounded hind wings, terminal appendages, and prominent subgenital plate (ovipositor) at the tip of their abdomen.

Photo used with written permission from Mike Boatwright.

Copyright © 2022 Walter Sanford. All rights reserved.

Arrowhead Spiketail (terminal appendages)

January 21, 2022

Arrowhead Spiketail dragonflies (Cordulegaster obliqua) were spotted along small streams at undisclosed locations in Fairfax County and Prince William County, Virginia USA.

Male and female Arrowhead Spiketails are similar in appearance. They can be differentiated based upon several field marks.

Male

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

07 JUL 2014 | Fairfax County | Arrowhead Spiketail (male)

Arrowhead male and female cerci are similar in appearance, and it can be challenging to see the epiproct clearly from some viewpoints. When in doubt whether an individual is male or female, look for indentations at the base of the hind wings of males.

07 JUL 2014 | Fairfax County | Arrowhead Spiketail (male)

Female

This individual is a female, as indicated by her rounded hind wings, terminal appendages, and prominent subgenital plate (ovipositor) at the tip of her abdomen.

21 MAY 2019 | PNC. Wm. County | Arrowhead Spiketail (female)

Although Arrowhead male and female cerci are similar in appearance, there is no mistaking the subgenital plate of female spiketails! It’s easy to see why “Spiketails” is the common name for Family Cordulegastridae.

21 MAY 2019 | PNC. Wm. County | Arrowhead Spiketail (female)

So the take-away is simple: If you see a subgenital plate then the individual is definitely female; if not, then it’s probably a male.

Copyright © 2022 Walter Sanford. All rights reserved.

New Life List additions in 2021

December 21, 2021

The anticipation of the hunt and the thrill of discovery — the adrenalin rush from finding new species of odonates is ever more elusive as one gains experience and expertise. Accordingly, the number of additions to my Life List is fewer year after year.

Selys’s Sundragon (Helocordulia selysii)

Selys’ Sundragon dragonfly (Helocordulia selysii) was spotted during a photowalk along a mid-size stream at an undisclosed location in Prince William County, Virginia USA.

This individual is a male with a malformed abdomen. Selys’s Sundragon is a new species for both my Life List of odonates and for Prince William County, VA.

13 APR 2021 | Prince William County, VA | Selys’s Sundragon (male)

Uhler’s Sundragon (Helocordulia uhleri) and Selys’s Sundragon are colocated at many sites — find one species and you should find the other. I’ve been on the lookout for Selys’s since Uhler’s was found several years ago near the site where this Selys’s was spotted.

Yellow-sided Skimmer (Libellula flavida)

Yellow-sided Skimmer dragonflies (Libellula flavida) were spotted around a small pond at an undisclosed location in Prince William County, Virginia USA.

The first individual is a female, as indicated by her terminal appendages.

17 JUN 2021 | PNC. Wm. County | Yellow-sided Skimmer (female)

The last individual is a male, as indicated by his blue coloration and terminal appendages.

17 JUN 2021 | PNC. Wm. County | Yellow-sided Skimmer (male)

Many species of dragonflies in the Family Libellulidae (Skimmers) are habitat generalists and relatively easy to find almost anywhere there is water. In contrast, Yellow-sided Skimmer is a habitat specialist that is challenging to find.

Tiger Spiketail (Cordulegaster erronea)

Tiger Spiketail dragonfly (Cordulegaster erronea) was captured along a small stream at an undisclosed location in Prince William County, Virginia USA. The specimen was photographed and released unharmed.

05 AUG 2021 | Prince William County, VA | Tiger Spiketail (male)

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

05 AUG 2021 | Prince William County, VA | Tiger Spiketail (male)

“Sight records are insufficient” is one of many “Walterisms.” In other words, I don’t add a species to my Life List until I have photographed it. And so it is with Tiger Spiketail. I have seen several Tiger Spiketail dragonflies during the past few years (at several locations) but had no photos to show for my efforts because they are fliers rather than perchers.

Copyright © 2021 Walter Sanford. All rights reserved.

Anatomy of a male Tiger Spiketail

August 10, 2021

The following annotated image shows a Tiger Spiketail dragonfly (Cordulegaster erronea). This individual is a male, as indicated by his hamules, “indented” hind wings, and terminal appendages.

Hamules

Hamules? What are hamules?

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.

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. Some species of dragonflies and damselflies — such as Ashy Clubtail versus Lancet Clubtail and Southern Spreadwing versus Sweetflag Spreadwing, to name a few — can be differentiated/identified with certainty only by examining the hamules under magnification.

Photo used with written permission from Michael Powell.

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

Indented hind wings

Male members of many families of dragonflies have “indented” hind wings near the body, with some notable exceptions.

Hind wing venation and shape can identify the sex of most dragonflies. Petaltails, darners (except Anax), clubtails, spiketails, cruisers, and some emeralds. Wing shape isn’t helpful to sex baskettails since they are largely the same. They are different in Cordulia, Dorocordulia, Somatochlora and to a lesser degree, Neurocordulia. Source Credit: Ed Lam, author and illustrator of Damselflies of the Northeast.

Terminal appendages

Identifying female versus male dragonflies and damselflies can be challenging but it’s a little easier when you know how to differentiate their terminal appendages.

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”). Male dragonfly terminal appendages don’t look exactly the same for all species of dragonflies, but their function is identical.

Generally speaking, spiketail dragonflies have relatively small terminal appendages. That said, they must get the job done!

Related Resource: Tiger Spiketail dragonfly (male) – a blog post by Walter Sanford.

Copyright © 2021 Walter Sanford. All rights reserved.

 

Tiger Spiketail dragonfly (male)

August 7, 2021

Tiger Spiketail dragonfly (Cordulegaster erronea) was captured along a small stream at an undisclosed location in Prince William County, Virginia USA. The specimen was photographed and released unharmed.

The first few images show Michael Powell, my former friend and photowalking buddy, holding the dragonfly while I shot some photographs.

05 AUG 2021 | Prince William County, VA | Tiger Spiketail (male)

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

05 AUG 2021 | Prince William County, VA | Tiger Spiketail (male)

What a handsome face! Cue “Eye Of The Tiger” by Survivor.

05 AUG 2021 | Prince William County, VA | Tiger Spiketail (male)

The next image shows me holding the dragonfly so that Mike could take some photographs. Hold That Tiger. (Strike up the band!)

Photo used with written permission from Michael Powell.

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

Up, up, and away!

The last photograph shows the Tiger Spiketail “posed” au naturel on the trunk of a fallen tree. Mike and I chose that spot because it was one of only a few sunny places along the small forest stream. The Tiger flew away almost immediately after I released him, headed toward the tree canopy. Mike had time for one clear shot. Good thing, ‘cuz I had no opportunity to get a shot.

Photo used with written permission from Michael Powell.

The backstory

I went on my first Tiger safari during July 2018 when I visited a location in Fairfax County, Virginia that a friend shared with me in strictest confidence. Although I saw several Tiger Spiketail dragonflies, every individual was in flight and I was unable to shoot still photos and/or video — they were gone by the time I reached for my camera!

Every year for the next few years, the story was similar — I saw Tigers but had no photos/videos to verify my sightings. Eventually I came to the conclusion that I would need to capture a specimen with an insect net in order to take photographs.

Let me be perfectly clear — all things being equal I would prefer to photograph dragonflies perching naturally rather than netting them. Sometimes, as in this case, netting is the better way to go.

Rest assured I have great respect for the rare- to uncommon species of odonates. The Tiger Spiketail featured in this post was held in captivity no longer than absolutely necessary, and was handled gently at all times.

Our strategy

Mike and I arrived at the stream site sometime after 10 a.m. While I setup my 18” diameter collapsible insect net, Mike took the point a little farther downstream to look for a Tiger approaching our location. No more than 10 minutes after I was in position alongside the stream, Mike spotted a Tiger flying upstream in our direction.

I waited until the Tiger had almost reached the place where I was standing before I swung my net forward smoothly and was psyched to see the dragonfly go all the way into the net. I said to Mike, “I got it!”

From that point, I worked quickly to gently remove the dragonfly from the net so that Mike and I could take some photographs of this rare species.

Range map

The following map shows all official records for Cordulegaster erronea in the United States of America. Tiger Spiketail is a habitat specialist that is challenging to find.

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

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.

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.

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.

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.


%d bloggers like this: