Archive for June, 2021

Unicorn Clubtail dragonfly (male)

June 29, 2021

A Unicorn Clubtail dragonfly (Arigomphus villosipes) was photographed near the shoreline of a small pond at an undisclosed location in Fairfax County, Virginia USA.

This individual is a male, as indicated by his terminal appendages. 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”).

For those of you keeping score at home, notice male Unicorn terminal appendages have four points/prongs. Does that mean A. villosipes is an exception to the rule of three terminal appendages for male dragonflies? In a word, no.

05 JUN 2021 | Fairfax County, VA | Unicorn Clubtail (male)

The preceding photo shows a clear view of the male’s terminal appendages. Zoom-in on the full-size version of the photo and you should notice that the epiproct for Unicorn Clubtail is essentially a wide plate with two points/prongs.

Related Resource: Odonate Terminal Appendages – a permanent reference page in my blog featuring identification guides for most of the common species of odonates found in Virginia, and even some of the uncommon to rare species.

Copyright © 2021 Walter Sanford. All rights reserved.

 

Yellow-sided Skimmer (female, male)

June 25, 2021

Thanks to a tip from fellow odonate enthusiast Michael Ready, I was able to add another species of dragonfly to my life list recently: Yellow-sided Skimmer dragonfly (Libellula flavida).

Female

The first Yellow-sided Skimmer dragonfly that I spotted was perched along the shoreline of a small pond at an undisclosed location in Prince William County, Virginia USA. This individual is a female, as indicated by her terminal appendages.

Female Yellow-sided Skimmers have a pair of flanges beneath their eighth abdominal segment that are used to scoop and hold a few drops of water when laying eggs (oviposition), hence the family name “Skimmer.” Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.

17 JUN 2021 | PNC. Wm. County | Yellow-sided Skimmer (female)

I followed the female from one perch to another, “working the shot.” The next two photos are full-frame (4,000 x 3,000 pixels), that is, uncropped.

17 JUN 2021 | PNC. Wm. County | Yellow-sided Skimmer (female)

Notice the amber color near the leading edge of her wings, a good field mark for L. flavida.

17 JUN 2021 | PNC. Wm. County | Yellow-sided Skimmer (female)

Male

According to Dr. Steve Roble’s excellent datasets for the Commonwealth of Virginia, the adult flight period for Yellow-sided Skimmer is from May 15 to September 21.

By mid-June most males, including this one, are completely covered by light-blue pruinescence that obscures the yellow coloration on the sides of their thorax. Look closely at the full-size version of the following photo and you should see the amber color near the leading edge of his wings.

17 JUN 2021 | PNC. Wm. County | Yellow-sided Skimmer (male)

Habitat

A small, seep-fed pond located in the forest provides ideal habitat for Yellow-sided Skimmer.

Habitat: Boggy ponds, seeps, slow streams, and weedy ditches. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Location 9094). Princeton University Press. Kindle Edition.

23 MAY 2018 | PNC. Wm. County | small, seep-fed pond

Notice the fallen tree that lies between the foreground and the pond in the background, nearly perpendicular to the stream. The tree is a barrier that slows the flow of the stream, creating the type of boggy, weedy habitat that Yellow-sided Skimmer prefers.

Range maps

Not all species of Skimmers are as common as I tend to think. For example, the following map shows all official records for Libellula flavida in the United States of America. As you can see, Yellow-sided Skimmer is a relatively uncommon species of odonate.

Zooming in to reveal the details shows few records reported for Northern Virginia, where I live.

What are the take-aways?

Many species of dragonflies in the Family Libellulidae (Skimmers) are habitat generalists and relatively easy to find almost anywhere there is water. In contrast, I think it’s fair to say Yellow-sided Skimmer is a habitat specialist that is challenging to find.

Related Resource: Libellula flavida Yellow-sided Skimmer on NatureServe Explorer. The conservation status for L. flavida in Virginia is “Vulnerable (S3).”

Copyright © 2021 Walter Sanford. All rights reserved.

What is it?

June 22, 2021

Ladies and gentlemen, children of all ages. It’s time for another exciting episode of “What is it?”

The Backstory

I spotted an odonate exuvia along the shoreline of a small pond at an undisclosed location in Prince William County, Virginia USA.

17 JUN 2021 | PNC. Wm. County | odonate exuvia

Mike Powell, my good friend and photowalking buddy, volunteered to collect the exuvia. I accepted his kind offer since I prefer dry shoes rather than wet ones. The following photo shows me holding the specimen immediately after Mike made the hand-off.

Photo used with written permission from Michael Powell.

Can you identify the odonate exuvia to the family level?

It should be easier to determine what it is by referring to A Beginners’ Guide to Identifying the Exuviae of Wisconsin Odonata to Family, by Freda Van den Broek and Walter Sanford. Although the guide is focused primarily on odonate exuviae found in Wisconsin, it should be useful for any location in the United States of America including Virginia.

I’m still working to identify the specimen to the genus and species level. Your mission, should you decide to accept it, is to identify the family of odonates to which this exuvia belongs.

If you think you know what it is, then please leave a comment. The answer will be revealed in a post update.

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

Gray Petaltail dragonflies (female, male)

June 18, 2021

Several Gray Petaltail dragonflies (Tachopteryx thoreyi) were observed at an undisclosed location in Fairfax County, Virginia USA. Only two individuals perched long enough to pose for photos.

The first one I spotted was perched relatively high on a tree on the earthen berm of a small pond. This individual is a female, as indicated by her rounded hind wings and terminal appendages. I was able to take just four photos of the female before she flew toward the top of the same tree.

05 JUN 2021 | Fairfax County, VA | Gray Petaltail (female)

Quite a while later, I spotted another Gray Petaltail land on another tree briefly, and by “briefly” I mean briefly. I had time for one shot as I was approaching the tree slowly, and just like that, the dragonfly flew toward the top of another tree. This individual is a male, as indicated by his “indented” hind wings and terminal appendages.

05 JUN 2021 | Fairfax County, VA | Gray Petaltail (male)

As it turns out, the preceding male was the last Gray Petaltail I saw for the day. Mike Powell and I had noticed the Grays seemed to be spending a lot of time in the tree canopy. I speculated their atypical behavior might be caused by the peak- or near-peak activity of Brood X Peridical Cicadas. Mike was, as always, skeptical of my speculation.

A little more than a week later, a post by Harold Bancroft White in the Northeast Odonata Facebook group seems to provide some support for my speculative theory. I like it when Gray Petaltails perch near the ground, so I hope their new hunting habit isn’t imprinted on the next generation!

Copyright © 2021 Walter Sanford. All rights reserved.

Spangled Skimmer (mature male)

June 15, 2021

A Spangled Skimmer dragonfly (Libellula cyanea) was spotted near a small pond at an undisclosed location in Fairfax County, Virginia USA.

This individual is a mature male, as indicated by his deep blue pruinescence and terminal appendages. Contrast the appearance of this mature male Spangled Skimmer with a teneral female spotted on 13 May 2021 at a location in Prince William County, Virginia USA.

05 JUN 2021 | Fairfax County, VA | Spangled Skimmer (mature male)

This guy seemed to be unusually skittish.

05 JUN 2021 | Fairfax County, VA | Spangled Skimmer (mature male)

I followed him to three different perches before he decided the photoshoot was finished and flew into a nearby tree.

05 JUN 2021 | Fairfax County, VA | Spangled Skimmer (mature male)

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.

I was common, when common wasn’t cool.

June 8, 2021

Common Whitetail dragonfly (Plathemis lydia) was observed during a photowalk along a mid-size stream at an undisclosed location in Prince William County, Virginia USA.

This individual is an immature male, as indicated by his mostly brown coloration, pattern of wing spots, and terminal appendages.

13 MAY 2021 | PNC. Wm. County | Common Whitetail (immature male)

This photo is one of a few “warm-up shots” I took at the outset of my photowalk. I think it’s a good idea to be sure your camera gear is working as expected before you blow an opportunity to photograph something rare to uncommon by fiddling with camera settings.

Copyright © 2021 Walter Sanford. All rights reserved.

Dragonfly socks

June 4, 2021

A good friend sent a special gift to me. I love me some dragonfly socks. Thanks, Susan!

I know you’re thinking “Gee, I wish had a pair of dragonfly socks.” But you don’t. Hah!

Copyright © 2021 Walter Sanford. All rights reserved.

Uhler’s Sundragon dragonfly exuvia

June 1, 2021

Michael Powell spotted a small odonate exuvia clinging to the base of one of two concrete abutments for a man-made dam located along a mid-size stream at an undisclosed location in Prince William County, Virginia USA.

I collected the exuvia in order to examine it more closely in my home laboratory/photography studio. Michael photographed the specimen in my hand immediately after I removed it from the abutment, as shown in the following photo.

Photo used with written permission from Michael Powell.

The first photo shows a face-head view of the exuvia.

13 APR 2021 | Prince William County, VA | Uhler’s Sundragon (exuvia)

The next two photos, showing a dorsal-lateral view of the specimen, confirm the exuvia is from a Uhler’s Sundragon dragonfly (Helocordulia uhleri).

Notice the dorsal hooks on abdominal segments seven through nine (S7-9). This distinctive character confirms the identity of the specimen as H. uhleri.

13 APR 2021 | Prince William County, VA | Uhler’s Sundragon (exuvia)

Another photo taken from the same view point, exposed and edited for more contrast, shows the three dorsal hooks a little more clearly than the preceding photo.

13 APR 2021 | Prince William County, VA | Uhler’s Sundragon (exuvia)

Knowing when good is good enough

A dear friend sent an article to me years ago entitled “Knowing when good is good enough.” I think she was trying to tell me something.

I tend to be a perfectionist. For example, I’m a man on a mission to take the best possible macro photographs of odonate larvae and exuviae given the limitations of my photography gear and small home studio.

Sometimes perfection is a road block that prevents me from shooting and posting photos that are more than serviceable for my purposes, in this case, informal instruction.

I did a quick Google search for the article from my friend. No luck, but I found one that’s close enough — you might even say one that’s good enough — for a little self-help.

None of the photographs in this blog post are perfect — not even close! But I published them anyway. Baby steps, Bob.

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.