Posts Tagged ‘hamules’

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.

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.

Blue-fronted Dancer damselfly

August 31, 2020

A Blue-fronted Dancer damselfly (Argia apicalis) was spotted during a photowalk with Michael Powell near Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR), Fairfax County, Virginia USA.

A. apicalis has “a blue form female and a brown form female.” Since neither the hamules nor terminal appendages can be seen clearly in the preceding photo, I’m unsure whether this individual is male or female.

Post Update

Michael Ready, good friend and fellow member of the Dragonfly Society of the Americas, shared the following comment via e-mail.

That’s an outstanding picture of a Blue-fronted Dancer. You state you are unsure of the individual’s gender. I am confident that it is a male. According to my field guides (Lam and Paulson), the blue-form female lacks the blue eyes and blue S8-10 that are apparent in your picture. Source Credit: Michael Ready.

Thanks for the kind words and helpful information, Michael! As it turns out, the field marks that you described are shown clearly in one of my blog posts: Blue-fronted Dancers (male, female), especially this photo.

Copyright © 2020 Walter Sanford. All rights reserved.

Acceptable uncertainty

July 27, 2020

A teneral damselfly was spotted by Michael Powell during a photowalk with me along a mid-size stream in Fairfax County, Virginia USA.

teneral: adult after it has just emerged, soft and not definitively colored. Source Credit: Glossary [of] Some Dragonfly Terms, by Dennis Paulson.

Teneral odonates, especially females, can be challenging at best to identify with certainty. And so it is with this one.

The first photo is the record shot. (Get a shot, any shot.) I think I might have just missed focus on the face.

No. 1 | 15 JUL 2020 | Fairfax County, VA | teneral damselfly

Refine the shot.

No. 2 | 15 JUL 2020 | Fairfax County, VA | teneral damselfly

Although this individual is definitely a member of Family Coenagrionidae (Narrow-winged Damselflies), both the genus/species and gender are somewhat uncertain.

It appears to be an Argia sp. based on long tibial spines. I think it is a male. Source Credit: Mike Boatwright, founder and administrator of the Virginia Odonata Facebook group.

For what it’s worth, Mike Powell and I saw three species of damselflies during our outing: Blue-tipped Dancer (Argia tibialis); Dusky Dancer (Argia translata); and Powdered Dancer (Argia moesta).

I’m not sure of the gender. I see what might be hamules, indicating this individual is male, but also see what looks like a female stylus (plural: styli) near the tip of the abdomen, indicating this might be a female.

Bonus Bugs and More

Look closely at Photo No. 1, the “record shot.” Notice the small orange colored insect perched along the bottom of the same rock on which the damselfly is perched. Can anyone identify Bonus Bug No. 1?

Post Update: “The fly at the [bottom] of this photo may be a black fly (Simuliidae).” Source Credit: John Smith, member “BugGuide” Facebook group.

Now look at Photo No. 2. Notice there is some type of dark insect that’s perched along the same edge of the rock as the damselfly. Can anyone identify Bonus Bug No. 2?

Post Update: “The bug at the bottom of your photo appears to be a caddisfly.” Source Credit: John Smith, member “BugGuide” Facebook group.

Also notice the dark insect is perched near what might be the exuvia from which the damselfly emerged, as shown in Photo No. 2. It’s tannish in coloration.

I didn’t see either the bonus bugs or possible exuvia when we were in the field. Of course!

Related Resource: Newly emerged damselflies, a companion blog post by Michael Powell.

Copyright © 2020 Walter Sanford. All rights reserved.

Spotlight on Slaty Skimmer

July 22, 2020

Michael Powell spotted a Slaty Skimmer dragonfly (Libellula incesta) during a photowalk with me along a mid-size stream in Fairfax County, Virginia USA.

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

15 JUL 2020 | Fairfax County, VA | Slaty Skimmer (male)

After a long day of searching for Eastern Least Clubtails (Stylogomphus albistylus) unsuccessfully — an uncommon species of dragonfly — it was good to see any type of dragonfly, including a common species like Slaty Skimmer!

Slaty Skimmer is a habitat generalist that can be found almost anywhere there is water.

Post Update

You know, sometimes I look at a full-frame photo and think it would look better cropped slightly. This is one of those times. So I cropped the photo and think it looks much better than the full-frame version. What do you think?

15 JUL 2020 | Fairfax County, VA | Slaty Skimmer (male)

Copyright © 2020 Walter Sanford. All rights reserved.

American Rubyspot damselfly (male)

June 24, 2020

During a photowalk with Michael Powell in Fairfax County, Virginia USA, Mike spotted an American Rubyspot damselfly (Hetaerina americana) perched facing the Potomac River. This individual is a male, as indicated by his red coloration, hamules, and terminal appendages.

All of the photos in the following gallery look similar, although there are subtle differences.

The first photo is the “record shot” for this individual, that is, “get a shot, any shot.” Actually, this one turned out to be a good photo! The camera was set for an aperture of f/5.6 for all shots in the gallery. This viewing angle provided the clearest look at his terminal appendages given the relatively shallow depth-of-field.

08 JUN 2020 | Fairfax County, VA | American Rubyspot (male)

The next photo shows a better look at the damselfly’s metallic ruby red face. Handsome!

08 JUN 2020 | Fairfax County, VA | American Rubyspot (male)

Finally, I just like the look of the “light” in the last photo. Dark and moody.

08 JUN 2020 | Fairfax County, VA | American Rubyspot (male)

Related Resource: American Rubyspot – a blog post by Michael Powell

Copyright © 2020 Walter Sanford. All rights reserved.

Calico Pennant dragonfly (male)

September 6, 2019

There’s a feeling I get
When I look to the west
And my spirit is crying for leaving.

A Calico Pennant dragonfly (Celithemis elisa) was observed during a photowalk with Michael Powell at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

This individual is a mature male, as indicated by his red coloration, the secondary genitalia (hamules) located on the underside of abdominal segments two-three (2-3), and terminal appendages.

Copyright © 2019 Walter Sanford. All rights reserved.

Fawn Darner dragonfly (male)

August 26, 2019

A Fawn Darner dragonfly (Boyeria vinosa) was spotted, netted, and released unharmed along the Little Patuxent River in the North Tract of Patuxent Research Refuge, Anne Arundel County, Maryland USA.

02 SEP 2012 | Patuxent Research Refuge | Fawn Darner (male)

This individual is a male, as indicated by the secondary genitalia (hamules) located on the underside of abdominal segments two-three (2-3).

02 SEP 2012 | Patuxent Research Refuge | Fawn Darner (male)

Thanks to Louisa Craven, my good friend and photowalking buddy, for holding the specimen in the first two photos while I used her Apple iPhone 4S to take photos. This was our first “stream walk” in search of dragonflies and damselflies and both of us were afraid to carry our camera gear as we waded in the river.

02 SEP 2012 | Patuxent Research Refuge | Fawn Darner (male)

The Backstory

I posted these photos in my Project Noah Nature Journal two days after an Audubon Naturalist Society field trip to the North Tract of the Patuxent Research Refuge, led by Richard Orr, renowned expert on odonates of the mid-Atlantic region of the United States.

Some of the photos from the Project Noah “spotting” were added to my photoblog in order to backfill my Life List of Odonates to include a record of an adult Fawn Darner.

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

Brown Spiketail dragonflies

May 6, 2019

Several Brown Spiketail dragonflies (Cordulegaster bilineata) were spotted during a photowalk with my good friend Mike Powell at Occoquan Regional Park, Fairfax County, Virginia USA.

Male

The first individual is a male, as indicated by his “indented” hind wings, and terminal appendages. Notice the epiproct for Brown Spiketail is a wide “plate” that spans both cerci, as shown in the full-size version of the following photo.

The next individual is also male, as indicated by his hamules, located below abdominal segments two and three (S2 and S3).

Female

The last individual is a female, as indicated by her rounded hind wings and terminal appendages.

Credits

Thanks to Michael Boatwright, founder and administrator of the Virginia Odonata Facebook group, for confirming my tentative identification of the gender of the first and last individuals.

Phenology

Phenology (noun) is defined as “the study of cyclic and seasonal natural phenomena, especially in relation to climate and plant and animal life.”

There is an annual cycle of odonate activity that can be subdivided into three broad categories: Early Season (spring); Mid-season (summer); and Late Season (fall).

Brown Spiketail is an “Early Season” species for locations in the Commonwealth of Virginia. I have noticed that the adult flight period for a given species of odonate in Northern Virginia tends to lag behind Amherst County, where my good friend Mike Boatwright (Mike B) lives, by about one-to-two weeks. When Mike B reported his first sighting of Brown Spiketail on 24 April in Amherst County, I knew it wouldn’t be long until Brown Spiketail would be flying in Fairfax County. Eight (8) days later, Mike Powell and I spotted our first-of-season Brown Spiketail dragonflies. Thanks for the heads-up, Mike B!

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

Test shots: Stylogomphus albistylus exuvia

December 19, 2018

Bob Perkins collected and reared an Eastern Least Clubtail dragonfly (Stylogomphus albistylus) nymph. This blog post features two focus-stacked composite images of the exuvia from the odonate nymph.

Nine photos were used to create the first focus stack. This small specimen features several easy-to-recognize field marks including large, dish-shaped antennae, distinctive color bands on the legs, lateral spines on abdominal segments eight and nine (S8-9), and terminal appendages tipped with a lighter color.

12 photos were used to create the last focus stack. This individual might be a male, as indicated by what appear to be vestigial hamules on the ventral side of the specimen.

Related Resources

Tech Tips

The following equipment was used to shoot all of the photographs for the two focus-stacked composite images, shown above: Canon EOS 5D Mark II digital camera, in manual mode; Kenko 20mm macro automatic extension tubeCanon EF100mm f/2.8L Macro lens (set for manual focus); and Canon MT-26EX-RT Macro Twin Lite set for “Master” mode, and several external flashes set for “Slave” mode including Canon 580 EX- and Canon 580EX II Speedlites and a Godox TT685C Thinklite TTL Flash fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.

Adobe Photoshop CC 2017 was used to create the focus-stacked composite images, as well as spot-heal and sharpen the final output.

Copyright © 2018 Walter Sanford. All rights reserved.


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