Hamules

A Russet-tipped Clubtail dragonfly (Stylurus plagiatus) was spotted during a photowalk at Mulligan Pond, Jackson Miles Abbott Wetland Refuge (JMAWR). This individual is a male, as indicated by the large russet-colored club at the end of his abdomen and by his prominent 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.

27 SEP 2016 | JMAWR | Russet-tipped Clubtail (male)

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

Like many species of Family Gomphidae (Clubtail dragonflies), the hamules of male Russet-tipped Clubtails are conspicuous — there’s nothing subtle about these guys!

Meme used with permission from Jacki Morrison (Minnesota Dragonflies).

The preceding meme features an outtake from “War of the Coprophages,” an episode of The X-Files (TV Series). Fox Mulder is an FBI agent who investigates paranormal activity; Dr. Bambi Berenbaum is a fictional scientist named after American entomologist Dr. May Berenbaum. I wasn’t into dragonflies when the episode aired in 1996, so the snippet of risque dialog about cockroaches (quoted in the meme) was lost on me. In retrospect, it’s clear that at least one of the writers/consultants for the episode must be quite familiar with dragonflies!

Copyright © 2016 Walter Sanford. All rights reserved.

When things go wrong

One week after I witnessed the miraculous metamorphosis of an emergent male Common Sanddragon dragonfly (Progomphis obscuris), I was reminded that a lot can go wrong during emergence. Like the old blues standard says…

When things go wrong, go wrong with you
It hurts me too.

08 JUN 2016 | Wickford Park | Common Sanddragon (emergent nymph)

An emergent nymph was spotted during a photowalk along Dogue Creek at Wickford Park. The nymph was in the same position hours later, so I’m sad to say the dragonfly was stuck in its exuvia.

08 JUN 2016 | Wickford Park | Common Sanddragon (emergent nymph)

Related Resource: Common Sanddragon dragonfly (emergent male), a blog post by Walter Sanford featuring a time-series of photographs documenting the metamorphosis of an emergent male Common Sanddragon dragonfly on 01 June 2016 at Wickford Park.

Copyright © 2016 Walter Sanford. All rights reserved.

Common Sanddragon dragonfly (male)

A Common Sanddragon dragonfly (Progomphus obscurus) was spotted during a photowalk along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is a male, as indicated by his coloration and terminal appendages.

08 JUN 2016 | Wickford Park | Common Sanddragon (male)

Like all male clubtail dragonflies, the hindwings of male Common Sanddragons are “indented” near the body. This distinctive field marker is shown well by the first, fourth, and last photos in this gallery.

08 JUN 2016 | Wickford Park | Common Sanddragon (male)

Half of the photographs in this set are full-frame, that is, uncropped. Like the next photo. Knee-high rubber boots enabled me to photowalk the stream channel, allowing me to get much closer to the subject. This guy is the second of at least five adult males I was able to photograph at close range during the outing.

08 JUN 2016 | Wickford Park | Common Sanddragon (male)

Some people imagine the yellow markings along the abdomen look like small burning candles.

08 JUN 2016 | Wickford Park | Common Sanddragon (male)

08 JUN 2016 | Wickford Park | Common Sanddragon (male)

08 JUN 2016 | Wickford Park | Common Sanddragon (male)

Copyright © 2016 Walter Sanford. All rights reserved.

Russet-tipped Clubtail claspers

Another Russet-tipped Clubtail dragonfly (Stylurus plagiatus) was spotted during a photowalk at Mulligan Pond, Jackson Miles Abbott Wetland Refuge (JMAWR).

This individual is a male, as indicated by the large russet-colored club at the end of his abdomen, “indented” hindwings (see annotated image, below), and his terminal appendages.

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

I like the way the hint of red coloration in the fall foliage complements the male’s russet-colored club.

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

This guy was by far the most cooperative of several Russet-tipped Clubtails spotted at the same location, as evidenced by the fact that he allowed me to shoot 119 photos in a variety of poses. Several of the better photos in the set were cherry-picked for this post; more photos may be published in a follow-up post.

14 OCT 2016 | JMAWR | Russet-tipped Clubtail (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 large “plate” that spans both cerci, as shown in the full-size version of the preceding photo.

Male Russet-tipped Clubtails have a larger, more colorful club than females of the same species, and their terminal appendages are shaped differently. Compare and contrast the appearance of males and females by looking at the following “Related Resources.”

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 © 2016 Walter Sanford. All rights reserved.

Another sighting of Russet-tipped Clubtail

It was my good fortune to see another Russet-tipped Clubtail dragonfly (Stylurus plagiatus) on 03 October 2016 during a photowalk at Mulligan Pond, Jackson Miles Abbott Wetland Refuge (JMAWR).

This one was by far the most challenging to spot/rewarding to find because the dragonfly was perching high in a cedar tree where it was well camouflaged.

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

This individual is a male, as indicated by the large russet-colored club at the end of his abdomen, and his terminal appendages. Notice the epiproct is a large “plate” that spans both cerci, as shown in the full-size version of the following photo.

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

I love a good head-tilt, as shown in the next photo.

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

I like the way the coloration of the male Russet-tipped Clubtail complements the color palette of the background in all of the photos.

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

Copyright © 2016 Walter Sanford. All rights reserved.

Another Russet-tipped Clubtail

I was eager to see another Russet-tipped Clubtail dragonfly (Stylurus plagiatus) after I spotted one on 22 September 2016 during a photowalk at Mulligan Pond, Jackson Miles Abbott Wetland Refuge (JMAWR).

A male Russet-tipped Clubtail was observed on 25 September 2016 at JMAWR, but it was only a fleeting glimpse. When I spotted him, he was flitting around looking for a perch — after two “touch-and-gos” he flew toward the trees in the distance and I never saw him again.

Another Russet-tipped Clubtail was spotted on 27 September 2016 that was more cooperative. This individual is a male, as indicated by the large russet-colored club at the end of his abdomen, and his terminal appendages.

27 SEP 2016 | JMAWR | Russet-tipped Clubtail (male)

Notice this male has tattered wings; the one spotted on 22 September does not. Facing forward, there’s a nick in the lower-left hindwing (above), and a chunk is missing from the upper-right forewing (below). Although this post is entitled Another Russet-tipped Clubtail, this male could be the same one seen on either the 22nd or the 25th with wing damage sustained during the interval between photowalks.

27 SEP 2016 | JMAWR | Russet-tipped Clubtail (male)

I love a good head-tilt, as shown in the preceding photo. But wait, there’s more to love — the hint of fall in the foliage in all of the photos.

27 SEP 2016 | JMAWR | Russet-tipped Clubtail (male)

Also notice all of the photos in this gallery show excrement extending from the tip of the abdomen. I’m a paparazzi who likes to photograph odonates “going about their usual life routines,” including doing their business. Hey, life happens!

27 SEP 2016 | JMAWR | Russet-tipped Clubtail (male)

27 SEP 2016 | JMAWR | Russet-tipped Clubtail (male)

Copyright © 2016 Walter Sanford. All rights reserved.

Russet-tipped Clubtail dragonfly (male)

A Russet-tipped Clubtail dragonfly (Stylurus plagiatus) was spotted near Mulligan Pond during a photowalk at Jackson Miles Abbott Wetland Refuge (JMAWR). Russet-tipped Clubtail is a new species on my life list of odonates. As far as I know, this is the first official record of Russet-tipped Clubtail at JMAWR.

Mulligan Pond is located along Dogue Creek, a tributary of the Potomac River. According to Chris Hill, current president of the Dragonfly Society of the Americas, Stylurus plagiatus “is a species of bigger rivers.” Chris speculates this Russet-tipped Clubtail probably emerged from the Potomac River and flew upstream along Dogue Creek to JMAWR.

22 SEP 2016 | JMAWR | Russet-tipped Clubtail (male)

This individual is a male, as indicated by the large russet-colored club at the end of his abdomen, and his terminal appendages.

22 SEP 2016 | JMAWR | Russet-tipped Clubtail (male)

I turned my camera at an unusual angle (somewhere between landscape and portrait) in order to get a better view of the dragonfly’s face, shown below. “Hanging Clubtails” is the common name for the genus Stylurus. As the name suggests, hanging clubtails typically perch with their abdomen hanging down, in contrast with many genera of clubtails that perch horizontally on the ground.

22 SEP 2016 | JMAWR | Russet-tipped Clubtail (male)

The last photo is my favorite of the set.

22 SEP 2016 | JMAWR | Russet-tipped Clubtail (male)

Copyright © 2016 Walter Sanford. All rights reserved.

Dragonhunter dragonfly exuvia

A Dragonhunter dragonfly (Hagenius brevistylus) exuvia was collected along the Little Patuxent River by Richard Orr, renowned expert on odonates of the mid-Atlantic region of the United States, during an Audubon Naturalist Society adult class and field trip on 15 June 2014 to the North Tract of Patuxent Research Refuge, Anne Arundel County, Maryland USA.

Dragonhunter [larvae] crawl out of the river and often cling on wet wood or roots/vegetation. I have seen them on mud but they seem to like vegetation or wood to cling to during emergence. I took a photo…of a cast skin at the same area [where this specimen was collected]. Source Credit: Personal communication from Richard Orr.

The decision tree used to identify the exuvia as a member of Family Gomphidae (Clubtails) is fairly simple and straightforward.

• The specimen has a flat labium (not mask-like).
• Antennae are either club-shaped or paddle-like (not thin and threadlike as in Aeshnidae).

Dragonhunter is the largest of North American clubtails; accordingly the large size and shape of a Dragonhunter exuvia is so distinctive that it is relatively easy to identify to the species level.

Lateral view showing left side, facing forward (annotated).

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

Notice the large, paddle-like antennae. They remind me of ping pong paddles.

Head-on view (annotated).

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

The large size and shape of Dragonhunter exuviae are key field marks.

Dorsal view.

All clubtail larvae/evuviae have a flat labium that doesn’t cover the face.

Ventral view (annotated).

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

Related Resources

• Photo showing dorsal view of a Dragonhunter exuvia (in situ), taken by Richard Orr on 01 June 2016 along the Little Patuxent River, Patuxent Research Refuge.
• Photo showing dorsal view of a Dragonhunter nymph [ruler shown for scale],  embedded on the following Web page: “Dragons and Damsels”: Odonata, Pt. I.
• Photo of a Dragonhunter naiad [nymph] (Hagenius brevistylus), showing a good head-on view of the paddle-like antennae.
• Odonate Exuviae, by Walter Sanford

Tech Tips

The following equipment was used to shoot the preceding photographs: Fujifilm X-T1 digital camera; Fujinon XF18-55mm (27mm-82.5mm, 35mm equivalent) zoom lens plus “Fotasy” brand 10mm extension tube; Fujifilm Shoe Mount Flash EF-42 (on-camera, in TTL mode); Nissin i40 external flash unit (off-camera, in SD mode). A snap-on plastic diffuser was used for each external flash.

Adobe Photoshop CC 2015 was used to annotate selected images.

Copyright © 2016 Walter Sanford. All rights reserved.

Gomphidae exuvia

A dragonfly exuvia was spotted by a friend at an unknown location in Northern Virginia. This specimen is a member of the Family Gomphidae (Clubtails). Here’s the decision tree I used to tentatively identify the exuvia as a member of the Clubtail Family.

• The specimen has a flat labium (not mask-like).
• Antennae are club-like (not thin and thread-like, as in Aeshnidae).
• Eyes not exceptionally large compared to the size of the head (not large, as in Aeshnidae).

Gomphidae is the second largest family of dragonflies, so it could be challenging to identify this specimen to the genus and species level.

Photo Set 1

Head-on view, ventral side up.

Notice the labium isn’t mask-like, that is, doesn’t cover the face of the larva/exuvia.

Head-on view, rotated 180°.

Anal pyramid view, ventral side up.

Head-on view, dorsal side up.

Lateral view, right side (facing forward).

Lateral view, left side (facing forward).

Photo Set 2

Dorsal view.

Ventral view.

Photo Set 3

Composite image.

The preceding composite image is a stack of 11 focus layers, moving from front-to-back across the face and head of the exuvia. Notice the labium isn’t mask-like, that is, doesn’t cover the face of the larva/exuvia. Also notice both antennae are club-like and most of the right antenna (facing forward) is missing.

Photo Set 4

The following macro photo shows a close-up of the face and head of the exuvia. The photo clearly shows the flat labium doesn’t cover any part of the face. Look closely at the full-size version of this image and you will notice two movable hooks at the front of the labium (see annotated illustration); they are reddish in color and the one on the left (relative to the photo) is more clearly in focus than the one on the right.

24x magnification.

Most, but not all, species of Gomphidae larvae are burrowers. The specimen is noticeably dirty — perhaps that indicates this individual is a burrowing species of clubtail dragonfly.

Related Resources

• Vimeo video: Identifying dragonfly larva to family (8:06)
• Anatomy of a Dragonfly Larva, annotated illustration courtesy Jay Smith
• Odonate Exuviae, by Walter Sanford

Tech Tips

The following equipment was used to shoot the preceding photographs:

• Photo Set 1: Canon EOS 5D Mark II digital camera; Canon EF 70-200mm f/2.8L zoom lens plus Kenko macro automatic extension tubes [12-, 20- and 36mm extension tubes (68mm, stacked)]; Canon 580EX Speedlite (on-camera, in ETTL mode).
• Photo Set 2: Canon EOS 5D Mark II digital camera; 50mm lens (“Nifty Fifty”) plus Kenko macro automatic extension tubes [12- and 36mm extension tubes (48mm, stacked)]; Canon 580EX Speedlite (ETTL mode) off-camera, using a pair of Yongnuo YN622C II Wireless Flash Trigger Transceivers; Nissin i40 external flash (off-camera, in Video mode); external flashes augmented by iPhone flashlight app.
• Photo Set 3: Canon EOS 5D Mark II digital camera; 50mm lens (“Nifty Fifty”) plus Raynox DCR-250 close-up filter; Canon 580EX Speedlite (ETTL mode) off-camera, using a pair of Yongnuo YN622C II Wireless Flash Trigger Transceivers; and a Nissin i40 (off-camera, in SF mode).
• Photo Set 4: Panasonic Lumix DMC-FZ150 plus Raynox DCR-250 close-up filter; Canon 580EX Speedlite (on-camera, in Manual mode); Nissin i40 (off-camera, in SF mode).

Adobe Photoshop CC 2015 was used for minor touch-up work on the background of all photos.

Copyright © 2016 Walter Sanford. All rights reserved.