Posts Tagged ‘Family Aeshnidae (Darners)’

Comet Darner exuvia: annotated images

October 8, 2021

My last blog post was a “sketch pad” of test shots of an exuvia from a Comet Darner dragonfly (Anax longipes) collected by Stanley Caveney on 19 July 2021 from a pond at MeadowWoods in West Elgin, Ontario, Canada. All of the shots in that post are unedited JPGs straight from my camera. This post features edited versions of the RAF (raw) files from that photo shoot, including some images with value-added annotations.

Lateral view

I considered annotating the first photo but decided to allow it to stand on its own as the latest addition to my Odonart© Portfolio.

Comet Darner (Anax longipes) | exuvia (lateral)

Ventral view

I used Adobe Photoshop to create a composite image that features the best parts of two photos from the sketch pad.

This specimen is from a male Comet Darner, as indicated by its vestigial primary- and secondary genitalia. The inset photo shows a clear view of the vestigial hamuli (secondary genitalia) that are partially obscured in the background photo.

Comet Darner (Anax longipes) | exuvia (ventral)

Prementum

The last photo shows a closer view of the mentum, a two-segment hinged “jaw” that is used to grab food: the prementum is the segment of the labium closer to the mouth; the postmentum is the segment closer to the base of the head. Only the prementum can be seen in the following photo.

Comet Darner (Anax longipes) | exuvia (prementum)

The preceding annotated image of the prementum includes labels for the moveable hooks (2 of 2) and palpal lobe (1 of 2). Notice that A. longipes palpal lobes are squared off, in contrast with the more rounded shape of the labial palps of Common Green Darner (Anax junius).

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

Comet Darner exuvia: photo sketch pad

October 5, 2021

Sometimes I shoot test shots of an odonate exuvia that are used to plan the final shots I have in mind for an identification guide featuring annotated photos.

All of the shots in this post are unedited JPGs straight from my camera, with the exception of the first ventral view (cropped to remove a distracting element from the composition).

Lateral view

I started with a lateral view of an exuvia from a Comet Darner dragonfly (Anax longipes) exuvia collected by Stanley Caveney on 19 July 2021 from a pond at MeadowWoods in West Elgin, Ontario, Canada.

Comet Darner (Anax longipes) | exuvia (lateral)

Ventral view

The next two photos show my frustratingly poor attempts to pose the specimen for shots of the ventral side of the exuvia. Every time I positioned the subject the way I wanted, it rolled over before I could take a shot!

Comet Darner (Anax longipes) | exuvia (ventral)

The two shots combined show the vestigial primary- and secondary genitalia that indicate this specimen is from a male Comet Darner. Yeah, I know it would help to annotate those parts of its anatomy, but that’s the next step. In the meantime, please follow the embedded hyperlink shown above and you might be able to figure out what I’m saying.

Comet Darner (Anax longipes) | exuvia (ventral)

Prementum

The last photo shows a closer view of the prementum. My goal was to get a better look at the labial palps. Again, annotations would help, but if you know what I’m talking about then you can see the palpal lobes are squared off.

Comet Darner (Anax longipes) | exuvia (prementum)

Copyright © 2021 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.

Taxonomy

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.

Previews of Coming Attractions – Fall Species of Odonates

August 31, 2021

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

As we endure the “Dog Days of Summer,” waiting for the calendar to turn to fall, it’s time to begin looking for the Late Season (fall) species of odonates.

This blog post provides a photo sampler of some of the fall species of odonates that can be seen during September, October, and November in the Commonwealth of Virginia. This post is not intended to be a comprehensive field guide that features every odonate species that can be seen during the same time period.

Full Disclosure

Some fall species are easier to find than others. And some species are flyers rather than perchers, making it almost essential to capture them in flight using an insect net. That being said, it’s richly rewarding to find any of the rare to uncommon species so do your homework and be persistent. Good luck and happy hunting!


Editor’s Notes

Click on the date listed in the caption for each photo to see the original blog post for that image; click on the odonate name to see all of my blog posts related to that species.

Sincere thanks to Michael Boatwright, founder and administrator of the Virginia Odonata Facebook group, for providing photographs of many of the rare to uncommon fall species of odonates featured in this photo sampler. Click on the word “Photo” in the caption for each of Mike’s photographs to see his original Facebook post for that image.

Every species features the following information: common name; scientific name; early-date/late-date; abundance; and habitat. All information is excerpted from “CHECKLIST OF THE DRAGONFLIES AND DAMSELFLIES OF VIRGINIA, April 2017 and April 2020 updates” by Dr. Steve Roble, Staff Zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage.


Dragonflies (Order Anisoptera)

Family Aeshnidae (Darners)

Black-tipped Darner (Aeshna tuberculifera)

Adult flight period: JUN 30 – OCT 29. Rare to uncommon. Habitat: Montane ponds.

Photo used with written permission from Michael Boatwright.

Common Green Darner (Anax junius)

Adult flight period: FEB 27 – DEC 30. Common. Habitat: Ponds.

Fawn Darner (Boyeria vinosa)

Adult flight period: JUN 03 – NOV 07. Common. Habitat: Streams, rivers.

Shadow Darner (Aeshna umbrosa)

Adult flight period: JUN 08 – DEC 05. Common. Habitat: Ponds, streams.

Family Corduliidae (Emeralds)

Clamp-tipped Emerald (Somatochlora tenebrosa)

Adult flight period: JUN 08 – OCT 15. Common. Habitat: Ponds, small streams.

Photo used with written permission from Michael Boatwright.

Fine-lined Emerald (Somatochlora filosa)

Adult flight period: JUL 10 – OCT 15. Rare to uncommon. Habitat: Boggy streams, swamps, marshes.

18 SEP 2019 | PNC. Wm. County | Fine-lined Emerald (male)

Family Gomphidae (Clubtails)

Arrow Clubtail (Stylurus spiniceps)

Adult flight period: JUN 13 – OCT 19. Uncommon to common. Habitat: Rivers.

Photo used with written permission from Michael Boatwright.

Laura’s Clubtail (Stylurus laurae)

Adult flight period: JUN 20 – SEP 26. Rare to uncommon. Habitat: Streams, rivers.

Photo used with written permission from Michael Boatwright.

Russet-tipped Clubtail (Stylurus plagiatus)

Adult flight period: JUN 15 – NOV 06. Uncommon to common. Habitat: Streams, rivers.

Family Libellulidae (Skimmers)

Autumn Meadowhawk (Sympetrum vicinum)

Adult flight period: MAY 28 – JAN 03. Common. Habitat: Ponds.

Blue-faced Meadowhawk (Sympetrum ambiguum)

Adult flight period: MAY 22 – NOV 19. Uncommon. Habitat: Swamps, ponds.

Black Saddlebags (Tramea lacerata)

Adult flight period: APR 12 – OCT 30. Common. Habitat: Ponds.

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

Spot-winged Glider (Pantala hymenaea)

Adult flight period: MAY 08 – OCT 20. Common. Habitat: Ponds.

A Spot-winged Glider dragonfly (Pantala hymenaea) netted at Saint Louis Catholic School, Fairfax County, Virginia USA. This individual is a female.

20 JUL 2016 | Fairfax County, VA USA | Spot-winged Glider (female)

Wandering Glider (Pantala flavescens)

Adult flight period: MAY 02 – NOV 17. Common. Habitat: Ponds.

Damselflies (Order Zygoptera)

Family Lestidae (Spreadwings)

Great Spreadwing (Archilestes grandis)

Adult flight period: JUN 25 – NOV 11. Uncommon. Habitat: Streams, ponds.

Spotted Spreadwing (Lestes congener)

Adult flight period: JUN 10 – NOV 11. Uncommon. Habitat: Ponds.

Photo used with written permission from Michael Boatwright.

 


Classification of Fall Species into Sub-groups

Migratory Species

At least five major species of dragonflies known to be migratory in North America.

  • Black Saddlebags (Tramea lacerata)
  • Common Green Darner (Anax junius)
  • Spot-winged Glider (Pantala hymenaea)
  • Wandering Glider (Pantala flavescens)

Rare to Uncommon Species

  • Arrow Clubtail (Stylurus spiniceps)
  • Black-tipped Darner (Aeshna tuberculifera)
  • Blue-faced Meadowhawk (Sympetrum ambiguum)
  • Clamp-tipped Emerald (Somatochlora tenebrosa)
  • Fine-lined Emerald (Somatochlora filosa)
  • Laura’s Clubtail (Stylurus laurae)
  • Ocellated Darner (Boyeria grafiana)
  • Great Spreadwing (Archilestes grandis)
  • Spotted Spreadwing (Lestes congener)

Copyright © 2021 Walter Sanford. All rights reserved.

Comet Darner dragonfly (exuvia)

August 27, 2021

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

This specimen is from 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.

19 JUL 2021 | Ontario, Canada | Comet Darner exuvia (lateral view)

Lateral spines along abdominal segments seven, eight, and nine (S7-9) indicate the genus is Anax; the length of the exuvia indicates longipes (~6 cm, measured as is).

The Backstory

Stanley Caveney is shown in the first of several photos taken by Hugh Casbourn. Stan contacted me for confirmation of his tentative identification of several Comet Darner exuviae that he collected during July 2021. Stan kindly gave one of the exuviae to me.

Photo used with written permission from Hugh Casbourn.

I asked Stan whether he had taken photographs of the Comet Darner exuviae in situ. Stan hadn’t, so he and Hugh revisited a local pond where they searched for and found two more exuviae.

How many exuviae do you see in the next photo? Look closely — both cast skins are shown in the same image.

Photo used with written permission from Hugh Casbourn.

An exuvia from a female Comet Darner appears in the foreground of the preceding photograph…

Photo used with written permission from Hugh Casbourn.

and a male Comet Darner appears in the background.

Photo used with written permission from Hugh Casbourn.

I asked Stan for advice regarding where to look for Comet Darner exuviae.

The six exuviae found to date were mainly at the inner edge of the cattail beds, facing the open water of the pond and where the individual cattail plants were spaced out. Source Credit: Personal communication from Stanley Caveney.

Related Resource: Identification Keys to Northeastern Anisoptera Larvae, compiled by Ken Soltesz. Refer to pp. 21-22.

Editor’s Note: Sincere thanks to Derek Caveney, Stan’s son, for shipping the exuvia to me. The specimen was packed so carefully that it arrived in excellent condition, as you can see in the first photo in this blog post. I’m looking forward to shooting a complete photo set of the exuvia.

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.

Springtime Darner dragonflies (female, male)

May 8, 2020

Several Springtime Darner dragonflies (Basiaeschna janata) were spotted during a photowalk with Michael Powell at an undisclosed location in Fairfax County, Virginia USA. Mike spotted the first one; then we teamed up to find a few more.

Female

Female Springtime Darners are polymorphic: the spots on their abdomen are either blue (andromorphic) or green (heteromorphic); the female featured in this post is a blue andromorph.

The terminal appendages and rounded shape of the hind wings can be used to identify andromorph female Springtime Darners.

“Get a shot, any shot; refine the shot” is one my mantras for wildlife photography. The first photo is an example of what some of my odonate hunter friends call a “record shot,” that is, a shot (any shot) that serves as a record of a spotting in the field.

Notice the photo appears to have been taken using only natural light. I speculate the external flash unit didn’t “wake up” from power-saving mode when I pressed the camera shutter. Do you see why I like to use fill flash for insect photography?

02 MAY 2020 | Fairfax County, VA | Springtime Darner (female)

Mike and I followed the female to a second location where we were able to shoot more photos.

02 MAY 2020 | Fairfax County, VA | Springtime Darner (female)

Refine the shot. (Get closer, in this case.)

02 MAY 2020 | Fairfax County, VA | Springtime Darner (female)

Male

The last individual is a male, as indicated by his terminal appendages and “indented” hind wings.

02 MAY 2020 | Fairfax County, VA | Springtime Darner (male)

All of the Springtime Darners that Mike and I spotted were very skittish, like the preceding male. I was only able to shoot one photo before he flew away. We couldn’t find it again.

Related Resource

Springtime Darner dragonflies” features photos of the same subject shot by Michael Powell: Mike used a DSLR camera, macro lens, and no flash to take his photos; I used a mirrorless superzoom “bridge” camera and an external flash unit to take mine.

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.


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