Posts Tagged ‘Common Green Darner dragonfly’

Common Green Darner dragonfly (external female reproductive anatomy)

June 5, 2020

For some species of odonate exuviae, sex is indicated by a form of remnant reproductive anatomy. These external structures don’t look exactly the same for all species of dragonflies and damselflies, but their function is identical.

As far as I know, this is true for all species in the Family Aeshnidae (Darners) such as Common Green Darner dragonfly (Anax junius).

The following photograph shows a ventral view of a female Common Green Darner dragonfly. Notice the external reproductive anatomical structure on abdominal segment nine (S9) is virtually identical to the remnant anatomical structure on S9 of the exuvia, shown above.

Original photo used with permission from Louisa C. Craven.

The Backstory

My dear friend Louisa Craven discovered the lifeless adult dragonfly while on vacation with her family in Nags Head, North Carolina USA. Louisa is an accomplished wildlife photographer who developed an interest in odonates as a result of many photowalks with me.

Related Resources

Copyright © 2020 Walter Sanford. All rights reserved.

My MYN technique studio macro photography rig

March 25, 2020

The following annotated photos show the current iteration of my “Meet Your Neighbours” (MYN) technique studio macro photography rig, set up at BoG Photo Studio, Fairfax County, Virginia USA.

This rig represents the culmination of continuous experimentation spanning several months — it works well most of the time but not always. Some of the gear shown in the photos is nice but not essential. Start small and add items as necessary.

An equipment list and legend follows the photo set.

My MYN macro photography rig, front view.

Notice the orientation of the clear plastic stage relative to the white plastic background, optimized for best exposure of both the white background and the subject.

My MYN macro photography rig, side view.

Most of the essential gear is shown in the following photo. However you set up the rig, all you really need is a translucent white background, some sort of clear plastic stage, one or more radio-controlled external flash units (with light diffusers), and a camera, of course. I’m guessing many photographers will have most of the necessary equipment on-hand already.

Close-up of clear plastic stage and white plastic background.

In this case, the subject is a Common Green Darner dragonfly (Anax junius) exuvia collected by Mike Powell, my good friend and photowalking buddy.

Equipment List (Legend)

  1. light stand (Promaster Deluxe Light Stand LS-2n)
  2. white plastic background
  3. clear plastic stage [part of a repurposed sandwich box from a delicatessen]
  4. Godox TT685F (fill flash, stage right)
  5. Canon 580EX II Speedlite (fill flash, stage left) fitted with a “Vello Bounce Dome (Diffuser) for Canon 580EX II Flash
  6. Godox X1R-C
  7. Lastolite Ezybox Speed-lite 2
  8. Tether Tools articulating arm [A large articulating arm is useful but DO NOT BUY Tether Tools articulating arms — they’re OVERPRICED and either work poorly (like this one) or not at all (like a smaller one shown in one of my YouTube videos)! Articulating arms and clamps made by Manfrotto are the best albeit expensive; arms and clamps made by SmallRig are a close second at a modest price point.]
  9. Westcott Reflector Arm Extreme
  10. Godox TT685C (backlight)

Everything is mounted on a Promaster Deluxe Light Stand LS-2n using the following Manfrotto articulating arms and clamps (and more).

A collection of articulating arms and clamps makes it easier to position everything exactly where it needs to be, enabling quick and easy set-up, repositioning, and break-down.

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Copyright © 2020 Walter Sanford. All rights reserved.

Laowa 25mm Ultra Macro (Canon mount)

March 23, 2020

Canon EF & RF, Nikon F & Z, Pentax K & Sony FE mounts are available. Source Credit: Laowa 25mm f/2.8 2.5-5X Ultra Macro, Venus Optics.

I bought the Canon mount plus the Canon EF lens to Fujifilm X mount camera adapter for use with my Canon EOS 5D Mark II DSLR and Fujifilm X-Series mirrorless digital cameras.

My Canon 5DM2 features a “full-frame” digital sensor; both my Fujifilm X-T1 and X-T3 cameras feature an APS-C digital sensor.

The following photo is an un-cropped, full size image from the full-frame digital sensor in my Canon 5DM2. Notice how much smaller the subject appears to be in this photo, in contrast with one of the un-cropped, full size images of the same specimen taken with my Fujifilm X-T1.

25mm (2.5x magnification) | ISO 100 | f/8 | 1/200 s | 0 ev

The Fujifilm X-T1 has a crop factor of 1.5x. In addition, the Canon-to-Fujifilm adapter (~1.25″ thick) increases magnification like the net effect of adding one or more extension tubes between the lens and focal plane of the digital image sensor.

The same photo was rotated slightly and cropped for better composition. Pretty good for a one-off shot at an aperture of f/8! Or was it f/5.6? I can’t remember and the EXIF info says f/0 because there aren’t any electronic contacts between the lens and camera body, so no help there.

25mm (2.5x magnification) | ISO 100 | f/8 | 1/200 s | 0 ev

Related Resources

Copyright © 2020 Walter Sanford. All rights reserved.

More Laowa 25mm Ultra Macro

March 20, 2020

The Laowa 25mm Ultra Macro lens is challenging to focus in low light — commentary common to all of the videos I cited in my last blog post (see “Related Resources”) that is consistent with my limited experience using the lens.

As an aid to focusing the camera on the subject, I added a Sunpak LED-160 Video Light to my “Meet Your Neighbours” technique studio photography rig. The bright continuous LED light enabled me to see the red focus peaking displayed by my camera for the first time!

25mm (2.5x magnification) | ISO 200 | f/5.6 | 1/180 s | 0 ev

Both photos featured in this post are “one-offs,” that is, not composite images. Although the depth of field is so shallow that a lot of the subject is out of focus, one look at these photos and I can tell the Laowa lens will work well for creating focus stacks.

25mm (2.5x magnification) | ISO 200 | f/8 | 1/180 s | 0 ev

Both photos are uncropped, full size images from an APS-C digital camera sensor. An aperture of either f/5.6 or f/8 is the “sweet spot” for this lens, according to the video reviews I watched.

The Backstory

The subject is a Common Green Darner dragonfly (Anax junius) exuvia collected by Mike Powell, my good friend and photowalking buddy. Although the exact date and location are unknown, we know the specimen was collected sometime during 2019 somewhere in Northern Virginia.

Copyright © 2020 Walter Sanford. All rights reserved.

Luminous beings are we…

December 13, 2019

Master Yoda’s explanation of the Force to Luke Skywalker (see Related Resources, below) features the following memorable quote.

Luminous beings are we,
not this crude matter.

One of many reasons I like the “Meet Your Neighbours” technique for photographing natural subjects against a pure white background is that it seems to reveal the luminous beings that odonate exuviae are. Feel the force by looking at the full-size version of the following image.

Related Resources

Tech Tips

I added a Raynox DCR-250 close-up filter to my Panasonic Lumix DMC-FZ300 24x superzoom bridge camera for a closer view of the anterior of the odonate exuvia.

The camera was set for 1-Area Focusing. The focus-and-recompose technique was used to focus on the eye of the subject.

Godox X2To/p wireless flash trigger for Olympus and Panasonic was used to fire two off-camera flash units.

  1. A Godox TT685C Thinklite Flash for Canon Cameras (manual mode), fitted with a “Vello Bounce Dome (Diffuser) for Canon 580EX II Flash,” was used to light the underside of the translucent white plastic background; the top of the flash unit was ~30 cm from the bottom of the white plastic.
  2. Godox TT685o/p Thinklite Flash for Olympus/Panasonic Cameras (manual mode), fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier, was used to light the subject from above.

Copyright © 2019 Walter Sanford. All rights reserved.

Puzzle solved: Anax junius exuvia (female)

December 11, 2019

Identifying odonate exuviae is a lot like solving a jigsaw puzzle — eventually all of the puzzle pieces fit together to reveal a clear picture. As it turns out, while I’ve been experimenting with the “Meet Your Neighbours” technique for photographing natural subjects against a pure white background, I was also collecting puzzle pieces that would enable me to identify the dragonfly exuvia.

A two-step process was used to identify the genus and species of the specimen featured in my last two blog posts.

  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 I 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.
  • Antennae are thin and thread-like (not club-like, as in Gomphidae larvae), as shown in Photo No. 1.
  • Eyes are large relative to the size of the head, as shown in Photo No. 1 and 4.

No. 1 | Common Green Darner (Anax junius) | exuvia (face-head)

Step 2. Genus and species

As shown in Photo No. 2 and 4, lateral spines along abdominal segments seven, eight, and nine (S7-9) indicate the genus is Anax.

No. 2 | Common Green Darner (Anax junius) | exuvia (ventral view)

At this point, you know the species could be either junius (Common Green Darner dragonfly) or longipes (Comet Darner dragonfly). The species is determined by the shape of the palpal lobes (part of the prementum) and the length of the specimen.

No. 3 | Common Green Darner (Anax junius) | exuvia (ventral view)

Notice the palpal lobes are rounded, as shown in Photo No. 3. The specimen is ~4.7 cm (~1.9 in) in length, not counting a slight bend in the body.

No. 4 | Common Green Darner (Anax junius) | exuvia (dorsal view)

The rounded shape of the palpal lobes (see Photo No. 3) plus the length of the specimen (see Photo No. 4) indicate the species is juniusAnax junius is one of the more common species of Aeshnidae found in Northern Virginia.

Finally, the rudimentary ovipositor shown in Photo No. 2 indicates this individual is a female.

Related Resource: Anax junius exuvia, another photo-illustrated identification guide by Walter Sanford.

Copyright © 2019 Walter Sanford. All rights reserved.

Common Green Darner dragonfly (young male)

September 27, 2019

A mini-swarm of Common Green Darner dragonflies (Anax junius) was spotted at a dry vernal pool, Old Colchester Park and Preserve (OCPP), Fairfax County, Virginia USA. A few Black Saddlebags dragonflies were mixed in with the swarm of A. junius.

Some of the dragonflies were hawking smaller insects; others were resting on vegetation. It’s probable members of the swarm had stopped to rest and refuel before continuing their southward migration.

The following Common Green Darner dragonfly was perched in a bed of dried cattails.

18 SEP 2019 | OCPP | Common Green Darner (young male)

This individual is a young male, as indicated by his terminal appendages. Notice there are points on the tips of his cerci, as shown in the full-size version of the preceding photo. Female cerci are pointless, both literally and figuratively.

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

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.

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.

Should I stay or should I go?

October 7, 2017

Two Common Green Darner dragonflies (Anax junius) were observed flying back-and-forth over a field alongside a vernal pool at a remote location in Huntley Meadows Park (HMP), Fairfax County, Virginia USA — typical feeding behavior for Common Green Darners. Sometimes they would land briefly, perching in shady hidey-holes in the thick vegetation covering the ground. I followed one of the two to a couple of perches.

This individual was very skittish! I was able to shoot one photo at the first perch…

03 OCT 2017 | HMP | Common Green Darner (female)

…and another photo at the last perch. The dragonfly flew toward the tree canopy when I tried to move a step closer.

03 OCT 2017 | HMP | Common Green Darner (female)

It’s relatively easy to identify this type of dragonfly to the species level.

The easiest field mark for identification of a Common Green Darner is that “bull’s eye” on the back of the head. No other [odonate] has it. Source Credit: John Gregoire, Kestrel Haven Wildlife Sanctuary.

On the other hand, it can be more challenging to identify the gender.

Several field marks can be used to identify the gender of this dragonfly. The cerci (sing. cercus) of female Common Green Darners look like almonds, both in color and shape. Two more field marks verify this specimen is female.

Note the brown stripe extending onto abdominal segment 2. Segment 2 [S2] is typically all pale on males. Also [viewing the second photo at full resolution and zooming in on the head] the rear margin of the occiput is not straight. Females have blunt dark colored “teeth” back there which makes the margin look wavy. Source Credit: Ed Lam, author and illustrator of Damselflies of the Northeast, Northeast Odonata Facebook group.

Common Green Darner is one of at least five major species of dragonflies known to be migratory in North America. It’s possible the two Common Green Darners that I observed stopped at Huntley Meadows Park in order to “refuel” before continuing their southward migration.

Related Resources

Copyright © 2017 Walter Sanford. All rights reserved.


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