Posts Tagged ‘Family Aeshnidae (Darners)’

Common Green Darner (female)

May 1, 2019

A Common Green Darner dragonfly (Anax junius) was perched on a tree, approximately one-to-two feet above the ground. My good friend Mike Powell spotted this beautiful specimen while we were hunting for Harlequin Darner alongside Wildlife Loop trail at the North Tract of Patuxent Research Refuge (PRR), Laurel, Maryland USA.

This individual is a female, as indicated by her terminal appendages. Sexing Common Green Darner dragonflies is a photo-illustrated field guide that describes field marks that can be used to differentiate female and male Common Green Darners.

It’s worth noting that both photos featured in this blog post are uncropped, that is, full resolution for the Panasonic Lumix DMC-FZ300 superzoom bridge camera (4,000 x 3,000 pixels).

The following photo is one of my “record shots” for this subject. Whenever I see a dragonfly perched on a tree, I always try to refine the shot until the tree in the background fills the entire frame. If you compare/contrast the two photos, then I think you will agree with me that the composition of the first photo is much better than the second.

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

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Harlequin Darner dragonfly (female)

April 24, 2019

On Earth Day 2019 my good friend Mike Powell and I traveled to the North Tract of Patuxent Research Refuge, Laurel, Maryland USA. Our target species: Harlequin Darner (Gomphaeschna furcillata), one of only two species in Genus Gomphaeschna, the Pygmy Darners.

Working the shot

A Harlequin Darner dragonfly was perched on a tree, approximately head height, near a mid-sized pond. This individual is a female, as indicated by her rounded hind wings and terminal appendages. All female dragonflies have a pair of cerci (superior appendages) that have little or no function. Both cerci are visible clearly in the full-sized version of the following photo.

Harlequin Darner is a new species for my life list of odonates.

First contact

Those who know me well are familiar with one of many “Walterisms”: “Get a shot, any shot; refine the shot.” The following photo is the “record shot”; the preceding photo shows one of my attempts to refine the record shot.

The record shot shows a better view of the female’s face than the refined shot, as shown in the following closer crop of the same photo.

Credits

Sincere thanks to Richard Orr and Rick Borchelt for detailed guidance regarding two sites where Harlequin Darner is known to occur at Patuxent Research Refuge as well as lots of practical tips for finding G. furcillata in the field.

Richard is a renowned expert on odonates of the mid-Atlantic region of the United States, and Rick is Director for Communications and Public Affairs, Office of Science at U.S. Department of Energy.

The Backstory

Harlequin Darner and Taper-tailed Darner (Gomphaeschna antilope) are sibling species. Taper-tailed Darner is known to occur at Huntley Meadows Park, based upon confirmed sightings by Geoffrey Cohrs and Karen Sheffield, park staff members, Fred Siskind, park volunteer (photo used with permission), and Daryl & Erin Elliott. Since both Harlequin and Taper-tailed Darner are in the same genus and prefer the same habit, I speculated Harlequin should be found at Huntley Meadows too. Every spring I wandered the wetlands of Huntley Meadows Park in search of both species of the elusive Pygmy Darners. No luck.

After three years of frustration, I decided to expand my search area to include two hotspots in Maryland where there is a better chance of finding Harlequin Darner. I was fortunate to find my first Harlequin at the location closer to my home in Northern Virginia.

Related Resources: Digital Dragonflies, presenting high-resolution digital scans of living dragonflies.

  • Genus Gomphaeschna | G. furcillata | Harlequin Darner | male | top view
  • Genus Gomphaeschna | G. furcillata | Harlequin Darner | male | side view

See also Harlequin Darner dragonfly for Mike Powell’s take on our trip to Patuxent Research Refuge.

Copyright © 2019 Walter Sanford. All rights reserved.

Composite image: Shadow Darner dragonfly

January 11, 2019

Bob Perkins collected and reared a Shadow Darner dragonfly (Aeshna umbrosa) larva/nymph. This blog post features a focus-stacked composite image of a beautifully preserved specimen of the adult that emerged from the larva.

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

Shadow Darner (Aeshna umbrosa) | face-head-dorsal

Artifacts

In my experience, focus stacking either works or it doesn’t. When it doesn’t work, “artifacts” appear in the final output that can be caused by many factors. There are work-arounds that can be used to repair the artifacts with mixed success. (See Tech Tips/Related Resources.)

I shot 19 photographs that were used to create a focus-stacked composite image of the Shadow Darner dragonfly. There’s a lot going on in those photos that caused too many artifacts to publish the final output. Several of the more noticeable artifacts are shown below.

I created another composite image; I used as many photos as I could before the first artifacts appeared. As it turns out, only five of 19 photos were used in the do-over composite image (shown at the beginning of this blog post). Look closely — some of the same artifacts are also noticeable in the do-over version.

Related Resources

Tech Tips

The following equipment was used to shoot the preceding composite image: Canon EOS 5D Mark II digital camera, in manual mode; Kenko macro automatic extension tubes (12mm, 20mm, and 36mm)Canon 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.

Auto power-off was disabled for the camera and all external flash units.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen the final output.

Tech Tips/Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

Test shots: Shadow Darner dragonfly

January 9, 2019

Bob Perkins collected and reared a Shadow Darner dragonfly (Aeshna umbrosa) larva/nymph. This is a preserved specimen of the adult that emerged from the larva.

Test shots of this beautiful specimen were taken using a relatively small aperture of f/16 for greater depth of field. The following photo is a “one-off,” that is, not a composite image.

Related Resource: Test shots: Aeshna umbrosa exuvia.

Tech Tips

The following equipment was used to shoot the preceding photograph: Canon EOS 5D Mark II digital camera, in manual mode; Kenko macro automatic extension tubes (12mm, 20mm, and 36mm)Canon 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.

Auto power-off was disabled for the camera and all external flash units.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen the final output.

Copyright © 2019 Walter Sanford. All rights reserved.

Test shots: Brachytron pratense exuvia (female)

December 10, 2018

As if it weren’t challenging enough to identify odonate exuviae from species native to the United States of America (where I live), I just started working with some specimens collected by a good friend during April 2018 in Vienna, Austria.

I decided to start with a specimen that I recognized immediately as a member of the Family Aeshnidae (Darners). Here’s the decision tree used to identify the family.

  • The specimen has a flat labium that doesn’t cover the face (not mask-like).
  • Antennae are thin and thread-like (not club-like, as in Gomphidae larvae/euviae).
  • Eyes are large relative to the size of the head.

One-off

The first photo is a “one-off,” that is, not a composite image. The focus point is on the face mask/head; the rest of the subject is in soft focus. I think this is a good way to draw the viewer’s eyes to a specific part of a photo, while adding a sense of depth.

Hairy Dragonfly (Brachytron pratense) | exuvia (face/head-dorsal)

Composite images

The next “photo” is a three-layer focus-stacked composite image: The focus point is on the face mask/head in the first photo; the thorax in the second photo; and the terminal appendages in the third photo. The entire body of the exuvia is acceptably in focus, including the legs.

Notice the unusual shape of the head. Head shape can be used to identify some species in Family Aeshnidae. Source Credit: Sue Gregoire, personal communication. Kestrel Haven Migration Observatory.

In fact, several members of the “Dragonflies and Damselflies – Worldwide Odonata” Facebook group were able to identify this specimen based upon the shape of its head and eyes. Sincere thanks to Tim Termaat, Hartwig Stobbe, and Rob Strik for kindly identifying this specimen as an exuvia from a Hairy Dragonfly (Brachytron pratense), also known as a Hairy Hawker.

Hairy Dragonfly (Brachytron pratense) | exuvia (dorsal-lateral)

The last “photo” is a four-layer focus-stacked composite image: The focus point is on the head in the first and second photos; the thorax in the third photo; and the terminal appendages in the fourth photo. The entire body of the exuvia is acceptably in focus, including the legs.

This individual is a female, as indicated by the rudimentary ovipositor that can be seen clearly on the ventral side of abdominal segment nine (S9).

Hairy Dragonfly (Brachytron pratense) | exuvia (ventral)

Related Resources

Tech Tips

The following equipment was used to shoot all of the preceding photographs: 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 two focus-stacked composite images, as well as spot-heal and sharpen the final output.

Copyright © 2018 Walter Sanford. All rights reserved.

Test shots: Aeshna umbrosa exuvia

December 3, 2018

Bob Perkins collected and reared an unknown species of odonate nymph from a tiny stream in Carroll County, Virginia USA. The larva emerged from one of Bob’s holding tanks overnight on 23-24 November 2018 and metamorphosed into an adult male Shadow Darner dragonfly (Aeshna umbrosa). Shadow Darner is a member of the Family Aeshnidae (Darners). The following test shots show the exuvia from the odonate nymph.

Test shots of this beautiful specimen were taken using a relatively small aperture of f/16 for greater depth of field. Each photo is a “one-off,” that is, not a composite image. Focus stacks will be created sometime in the near future, after the exuvia is rehydrated and its legs are repositioned  for easier posing.

Lateral-ventral view

The focus point of the first photo is on the right eye. Given the orientation of the specimen, most of the exuvia is acceptably in focus at f/16. For what it’s worth, I really like the composition of this photo!

Notice the specimen has a flat labium (prementum) that doesn’t cover the face (not mask-like). That is a characteristic field mark of two families of dragonflies: Family Aeshnidae (Darners); and Family Gomphidae (Clubtails).

Shadow Darner (Aeshna umbrosa) | exuvia (lateral-ventral)

This individual is a male, as indicated by vestigial hamules that are visible on the ventral side of the specimen.

Dorsal view

The focus point of the next photo is on the head: the head is tack-sharp; the terminal appendages are in soft-focus. Sometimes it’s necessary to create focus-stacked composite images in order to render the subject in focus from head-to-tail and edge-to-edge.

Lateral spines on abdominal segments six to nine (S6-9) indicate this specimen is A. umbrosa.

The focus point of the next photo is on the abdomen, just below the wing pads. Relative to the preceding photo, notice the head is slightly softer in focus while the terminal appendages are slightly sharper in focus.

Tech Tips

The following equipment was used to shoot all of the preceding photographs: 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 spot-heal and sharpen all three images.

Copyright © 2018 Walter Sanford. All rights reserved.

Mosquito Hawks

July 26, 2018

I’m honored to announce several of my dragonfly photographs are featured on new signage at Melvin L. Newman Wetlands Center, Clayton County, Georgia. The info-graphic, entitled “Mosquito Hawks,” was created by Danielle Bunch, Senior Conservationist for Clayton County Water Authority.

Image used with permission from Danielle Bunch.

As a retired K-12 science educator, I know from first-hand experience that informal learning opportunities can be as valuable as formal education in school classrooms. I was glad to contribute several of my photographs of Common Green Darner dragonflies (Anax junius) to the new info-graphic for the wetland area. It’s flattering to share the stage with Giff Beaton, author of Dragonflies and Damselflies of Georgia and the Southeast.

Full-size versions of my photographs (featured on the signage) appear in several previous posts on my photoblog.

Related Resources

Copyright © 2018 Walter Sanford. All rights reserved.

Springtime Darner (male claspers)

May 19, 2018

A Springtime Darner dragonfly (Basiaeschna janata) was spotted along Popes Head Creek at Hemlock Overlook Regional Park (HORP) in Fairfax County, Virginia USA. This individual is a male, as indicated by his terminal appendages and “indented” hind wings.

23 APR 2017 | HORP | Springtime Darner (male)

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

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”).

23 APR 2017 | HORP | Springtime Darner (male)

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

Editor’s Notes

The preceding photos are new, that is, previously unpublished. Both photos are full-frame (uncropped). Springtime Darners can be quite skittish. In this case, I was very close to an unusually cooperative model.

The last photo was shot using Aperture Priority. I prefer shooting in Shutter Priority, but I like to shoot a few shots using Aperture Priority whenever I can use either a monopod or tripod. In this situation, I improvised.

In addition to my photography gear, I usually carry a Coleman camp stool when I go photowalking. The small, lightweight folding chair is good for resting while waiting for “the game to come to me.” The camp stool also enables me to get closer to subjects either on- or near the ground, such as the Springtime Darner featured in this blog post. I think it’s easier to hold my camera rock-steady when I’m sitting on the chair with my elbows resting on my knees.

Copyright © 2018 Walter Sanford. All rights reserved.

Good luck charm

April 27, 2018

I noticed a golden/yellow horseshoe painted on both sides of a tree and thought, “This might be my lucky day.” Turns out the good luck symbol proved to be prophetic.

23 APR 2018 | Hemlock Overlook Regional Park | Horseshoe Trail

A yellow horseshoe is the trail marker for Horseshoe Trail at Hemlock Overlook Regional Park. Part of Horseshoe Trail is co-located with Union Mill Trail (marked in red); the latter leads to Popes Head Creek.

A Springtime Darner dragonfly (Basiaeschna janata) was spotted along Popes Head Creek, just downstream from what appears to be either a natural dam or beaver dam.

Habitat: Woodland streams and rivers with some current; also at beaver ponds along stream course… Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 4063-4064). Princeton University Press. Kindle Edition.

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

The preceding photo is full-frame, that is uncropped. Springtime Darners can be quite skittish. In this case, I was very close to the unusually cooperative model. A follow-up blog post will be published after I edit a large set of photos of this individual.

Copyright © 2018 Walter Sanford. All rights reserved.

Boyeria vinosa exuvia

March 8, 2018

Bob Perkins collected and reared an unknown species of odonate nymph from a stream located in southwestern Virginia. The larva emerged from one of Bob’s holding tanks on 08 May 2017 and metamorphosed into an adult female Fawn Darner dragonfly (Boyeria vinosa). Fawn Darner is a member of the Family Aeshnidae (Darners).

A two-step process was used to verify the genus and species of the exuvia.

  1. Determine the family.
  2. Determine the genus and species.

Step 1. Family

First, determine the family of the specimen. For reference, watch the excellent Vimeo video Identifying dragonfly larva to family (8:06). Here’s the decision tree used to identify the exuvia as a member of the Family Aeshnidae (Darners).

  • The specimen has a flat labium that doesn’t cover the face (not mask-like), as shown in Photo No. 1, 3, and 4.
  • Antennae are thin and thread-like (not club-like, as in Gomphidae larvae), as shown in Photo No. 1-4.
  • Eyes are large relative to the size of the head, as shown in Photo No. 1.

No. 1 | Boyeria vinosa | exuvia (face-head)

Step 2. Genus and species

The dichotomous key for Boyeria larvae that appears on p. 22 in Identification Keys to Northeastern Anisoptera Larvae, compiled by Ken Soltesz, was used to verify the genus and species of the exuvia.

1. Length when grown 37-39 mm;
Lateral spines on abdominal segments 4 to 9 (minute on 4);
Mentum of labium more than twice as long as its median width;
Inferior caudal appendages (paraprocts) stouter, scarcely incurved at tips;
Apex of superior anal appendage (epiproct) uncleft and sharply pointed;
Epiproct as long as paraprocts. [grafiana]

1’. Length when grown 34-37 mm;
Lateral spines on abdominal segments 5 to 9;
Mentum of labium less than twice as long as its median width;
Inferior caudal appendages (paraprocts) more slender, distinctly incurved at tips;
Apex of superior anal appendage (epiproct) deeply emarginate (cleft);
Epiproct distinctly shorter than paraprocts. [vinosa]

The exuvia is ~35 mm (~3.5 cm) long. Lateral spines are present on abdominal segments five to nine (S5 to S9).

No. 2 | Boyeria vinosa | exuvia (dorsal)

The rudimentary ovipositor shown in Photo No. 3 indicates this individual is a female.

No. 3 | Boyeria vinosa | exuvia (ventral)

The prementum is less than twice as long as its median width, as shown in Photo No. 4.

No. 4 | Boyeria vinosa | exuvia (prementum)

The paraprocts are incurved at the tips.

No. 5 | Boyeria vinosa | exuvia (anal pyramid)

There is a cleft in the apex of the epiproct. The cleft is closed in the exuvia (above); it is open in the nymph (below). Both photos show the same specimen, before and after emergence.

Image used with permission from Bob Perkins.

Both the Soltesz dichotomous key and the key for Boyeria larvae that appears on pp. 88-89 in Dragonflies of North America, Third Edition by Needham et al. describe the epiproct as “distinctly shorter than paraprocts.” The epiproct and paraprocts are nearly the same length. In the opinion of the author, this marker is least useful for differentiating grafiana and vinosa nymphs/evuviae.

This specimen is confirmed as an exuvia from a Fawn Darner dragonfly (Boyeria vinosa).

Adult

The adult Fawn Darner dragonfly emerged on 08 May 2017. Fawn Darners are, on average, 60-71 mm long (Paulson, 2011).

Image used with permission from Bob Perkins.

This individual is a female, as indicated by its rounded hind wings (above) and prominent ovipositor (below).

Image used with permission from Bob Perkins.

Tech Tips

The following equipment was used to shoot Photo No. 2 and 3: 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 LitePhoto No. 1, 4, and 5: Canon EOS 5D Mark II digital camera, in manual mode; Canon MP-E 65mm Macro lens (manual focus only, set for 2x – 3x magnification); and Canon MT-26EX-RT Macro Twin Lite.

Sunpak LED-160 Video Light (with a white translucent plastic filter) was used for all photos.

Adobe Photoshop CC 2017 was used to annotate selected images.

Bob Perkins’ photos were shot using a Canon EOS Rebel T3i camera body and Canon EF-S 60mm macro lens. The photos of the adult were taken soon after emergence.

Related Resource

The dichotomous key for Boyeria larvae that appears on pp. 88-89 in Dragonflies of North America, Third Edition by Needham et al. is as follows.

1. Epiproct about as long as paraprocts, its apex acute, not emarginate; greatest width of prementum about 3/5 its length; paraprocts shorter than abdominal segments 9+10, each with apex nearly straight (Fig. 85). [grafiana]

1’. Epiproct distinctly shorter than paraprocts, its apex distinctly emarginate; greatest width of prementum about 2/3 its length; paraprocts longer than abdominal segments 9+10, each with apex distinctly incurved (Fig. 85). [vinosa]

Post Update

Thanks to Northeast Odonata Facebook group members Curt Oien and Nick Block for sharing the following helpful tips. Both Curt and Nick are also members of the Dragonfly Society of the Americas.

The face-head of an Aeshnidae nymph/exuvia is relatively easy to recognize. Would I have said that when I was a beginner? In a word, no. Watch the Vimeo video a few times and you’ll see what I’m saying.

So, after you determine a specimen is from the Family Aeshnidae, look for a prominent light-colored diamond shape on the dorsal side of abdominal segment eight (S8), as shown in Photo No. 2 and 5: if it’s there, then you can be fairly certain the genus is Boyeria.

Curt looks for the cleft in the epiproct to determine the species. I recommend looking at other markers that are easier to see.

Copyright © 2018 Walter Sanford. All rights reserved.


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