Posts Tagged ‘Anax junius’

Common Green Darner exuviae (male vestigial genitalia)

December 6, 2022

Male odonates in Suborder Anisoptera (Dragonflies) have two sets of sex organs: primary genitalia located on abdominal segment nine (S9); and secondary genitalia located on abdominal segments two-to-three (S2-3).

For some (but not all) species of odonate larvae/exuviae, sex is indicated by either a rudimentary ovipositor (female) or vestigial genitalia (male). These sex organs don’t look exactly the same for all species of dragonflies, but their function is identical.

The following annotated images show the male vestigial genitalia for two Common Green Darner (Anax junius) exuviae collected by Jason Avery during Summer 2022 in Calvert County, Maryland USA. All of the images show the ventral side of the exuviae.

Male No. 1

Summer 2022 | Common Green Darner (Anax junius) | exuvia (male)

Summer 2022 | Common Green Darner (Anax junius) | exuvia (male)

Male No. 2

Summer 2022 | Common Green Darner (Anax junius) | exuvia (male)

Look closely at the following image and you should notice the secondary genitalia appear to extend from S2 to S3. In this case, only the more prominent parts on S3 are labeled.

Summer 2022 | Common Green Darner (Anax junius) | exuvia (male)

Related Resources

Tech Tips

All of the preceding images were photographed by Jason Avery and annotated by Walter Sanford. Thanks to Jason for kindly sharing his photos!

Copyright © 2022 Walter Sanford. All rights reserved.

Jumping spider

March 15, 2022

The following photo shows a tiny spider carcass (~3/16″ long) that was inside an exuvia (~1 3/4” long) from a Common Green Darner dragonfly (Anax junius). The exuvia was collected on 17 June 2021 from a small pond in Prince William County, Virginia USA. I discovered the spider long afterward — too late to save its life.

17 JUN 2021 | PNC. Wm. County, VA | Jumping spider

Thanks to Eva Weiderman and Joseph Girgente — members of the “Odonate Larvae and Exuviae” Facebook group — for their help in identifying the specimen as a jumping spider, Family Saticidae.

Salticidae is one of several families of spiders with eight (8) eyes. My take-away from reading the reference on BugGuide entitled “Spider Eye Arrangements” is identification of this specimen to the genus and species level is challenging at best and impossible at worst.

In contrast, it’s well known that spiders use odonate exuviae for shelter. I wish the jumping spider had come out of its most excellent hidey-hole sooner!

17 JUN 2021 | PNC. Wm. County, VA | Anax junius exuvia

Related Resources

Tech Tips

The tiny jumping spider was photographed using a Panasonic Lumix FZ-300, Raynox DCR-250 close-up filter, Godox X2To/p flash trigger, and Godox TT685F plus Altura flash modifier. Camera settings: ISO 100 | f/7.1 | 1/60 s | 56.9mm (316mm, 35mm equivalent).

Raynox DCR-250 close-up filter” is a blog post in which I provide more information about how I use the Raynox with my Panasonic Lumix superzoom bridge cameras.

Copyright © 2022 Walter Sanford. All rights reserved.

Anax junius versus Anax longipes

September 10, 2021

The following photograph shows the relative size of odonate exuviae from two species in the Genus Anax: junius; and longipes. Both specimens are from the Family Aeshnidae (Darners).

Relative size of exuviae from Anax junius versus Anax longipes.

The Common Green Darner dragonfly (Anax junius) exuvia was collected on 17 June 2021 from a small pond at an undisclosed location in Prince William County, Virginia USA.

The Comet Darner dragonfly (Anax longipes) exuvia was collected by Stanley Caveney on 19 July 2021 from a pond at MeadowWoods in West Elgin, Ontario, Canada.


There are five species of dragonflies in the Genus Anax for the United States and Canada: Amazon Darner (Anax amazili); Common Green Darner (Anax junius); Comet Darner (Anax longipes); Giant Darner (Anax walsinghami); and Blue-spotted Comet (Anax concolor).

Common Green Darner and Comet Darner are the only species from the Genus Anax found where I live in Northern Virginia USA.

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

Post update: What is it?

July 6, 2021

I spotted an odonate exuvia along the shoreline of a small pond at an undisclosed location in Prince William County, Virginia USA that was collected by Mike Powell, my good friend and photowalking buddy.

This specimen is from the Family Aeshnidae (Darners), as indicated by the following field marks: the exuvia has a flat labium that doesn’t cover the face (not mask-like); the antennae are thin and thread-like (not club-like, as in Gomphidae larvae/exuviae); and the eyes are large relative to the size of the head.

17 JUN 2021 | PNC. Wm. County | Anax junius exuvia

Lateral spines along abdominal segments seven, eight, and nine (S7-9) indicate the genus is Anax; the length of the exuvia indicates junius (greater than ~4 cm, measured as is).

Common Green Darner dragonfly (Anax junius) is one of the more common species of Aeshnidae found in Northern Virginia.

Related Resource: What is it?

Copyright © 2021 Walter Sanford. All rights reserved.

Common Green Darner (male)

June 11, 2021

A Common Green Darner dragonfly (Anax junius) was observed during a photowalk with Michael Powell along a mid-size stream at an undisclosed location in Prince William County, Virginia USA.

While I was searching for the mythical Appalachian Snaketail dragonfly (Ophiogomphus incurvatus), Mike was tracking several Common Green Darners hawking flying insects over a large field near the stream. Thanks to Mike for giving me a heads-up when one of the darners landed in the field.

13 MAY 2021 | PNC. Wm. County | Common Green Darner (male)

This individual is a male, as indicated by his terminal appendages. Sometimes, as in this case, identifying sex can be challenging. Sexing Common Green Darner dragonflies is a blog post I created that illustrates several field marks can be used to identify the gender of female and male Anax junius.

The Backstory

I think the location that Mike and I visited provides the right habitat for Appalachian Snaketail dragonflies. Although we didn’t find the target species on the day of our visit I remain convinced O. incurvatus is there, waiting to be discovered.

Tech Tips

Notice the tips of the dragonfly’s cerci are near the bottom of the photo frame. I prefer to give the subject a little more “breathing room” but this image is the best one from the set of photos I shot and it is what it is — as close as I could get without spooking the dragonfly, albeit less than perfectly composed.

Copyright © 2021 Walter Sanford. All rights reserved.

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.

Related Resources

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.

Editor’s Note: I was wrong. There I said it. For details, see the “Post Update” below.

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

Post Update

Just because something looks like a duck and seems to act like a duck doesn’t mean it’s a duck. And so it is with the Canon EF lens to Fujifilm X mount camera adapter made by Laowa — although it looks like an extension tube, it isn’t. Why was I deceived by its appearance? Because I didn’t understand something called “flange focal distance.”

For an interchangeable lens camera, the flange focal distance (FFD) … of a lens mount system is the distance from the mounting flange (the interlocking metal rings on the camera and the rear of the lens) to the film or image sensor plane. This value is different for different camera systems. Source Credit: Flange focal distance. Wikipedia.

For example, the FFD for Canon EF-mount is 44 mm and the FFD for Fujifilm X-mount is 17.7 mm. In order to make a Canon EF lens perform properly on a Fujifilm X-series camera body, an adapter must move the Canon lens 26.3 mm farther from the digital sensor. (44 mm – 17.7 mm = 26.3 mm)

Not surprisingly, when I measured the thickness of my Canon EF lens to Fujifilm X mount camera adapter it turns out to be close to 26 mm. The net result is the 17.7 mm FFD of my Fujifilm X-T3 combines with the 26.3 mm thickness of the Laowa adapter, resulting in an FFD of 44 mm — exactly the right FFD for the Canon lens to work properly on a Fujiflm X-series camera body!

It’s worth noting that “apparent magnification” is still a real thing when a camera lens designed for a “full-frame” camera is mounted on a camera with an APS-C size sensor. The image formed by the lens is exactly the same size regardless of the size of the digital sensor used to record the image, but a smaller part of the image is “seen” by an APS-C sensor than a full-frame sensor, resulting in the misperception that the image is magnified.

I hope this sets the record straight. Sincere apologies for any confusion I might have caused — I never heard of “flange focal distance” before I wrote this blog post!

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.

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