Posts Tagged ‘female’

Yellow-sided Skimmer (terminal appendages)

August 24, 2021

Female and male Yellow-sided Skimmer dragonflies (Libellula flavida) were spotted at a small pond at an undisclosed location in Prince William County, Virginia USA.

Female

The first individual is a female, as indicated by her mostly yellow coloration and terminal appendages.

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

Female dragonflies have a pair of cerci (superior appendages) that have little or no function.

Mature male

The last individual is a mature male, as indicated by his light-blue pruinescence and terminal appendages.

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

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”).

Immature male Yellow-sided Skimmers look similar to females of the same species. Terminal appendages can be used to differentiate the sex of immature males and mature females.

Related Resource: Yellow-sided Skimmer (male and female) – a blog post by Walter Sanford.

Copyright © 2021 Walter Sanford. All rights reserved.

Black-shouldered Spinyleg (female)

August 13, 2021

A Black-shouldered Spinyleg dragonfly (Dromogomphus spinosus) was spotted by Michael Powell during a photowalk with me along a mid-size stream at an undisclosed location in Prince William County, Virginia USA.

This individual is a female, as indicated by her rounded hind wings and terminal appendages.

05 AUG 2021 | PNC. Wm. County | Black-shouldered Spinyleg (female)

We followed the female from one location…

05 AUG 2021 | PNC. Wm. County | Black-shouldered Spinyleg (female)

to another.

05 AUG 2021 | PNC. Wm. County | Black-shouldered Spinyleg (female)

I was able to take no more than three shots at each perch before she moved on to the next stop.

05 AUG 2021 | PNC. Wm. County | Black-shouldered Spinyleg (female)

Habitat

I’m not sure I’d call Black-shouldered Spinyleg a habitat specialist. I’ve seen and photographed D. spinosus along small streams in the forest, mid-size streams (like the one in this post), and large rivers.

Habitat: Rocky and muddy streams and rivers from small to large, more often in woodland. Also in rocky lakes in northern part of range. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 6416-6417). Princeton University Press. Kindle Edition.

Range map

The following map shows all official records for Dromogomphus spinosus in the United States of America. Given the wide range of lotic habitats where Black-shouldered Spinyleg is found, I’m puzzled by the fact that the species isn’t more widespread than it appears to be.

Related Resource: All posts in my blog tagged with the words “Black-shouldered Spinyleg dragonfly.”

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.

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.

Turn! Turn! Turn!

May 21, 2021

Perceptive observers of nature notice gradual changes that indicate the change of season.

To everything (turn, turn, turn)
There is a season (turn, turn, turn)
And a time to every purpose, under heaven.
Source Credit: Turn! Turn! Turn! Song by The Byrds

For example, sighting a Spangled Skimmer dragonfly (Libellula cyanea) is a sure sign the subtle transition from spring to summer is underway.

13 MAY 2021 | PNC. Wm. County, VA | Spangled Skimmer (teneral female)

One of my mantras for wildlife photography is “Get a shot, any shot; refine the shot.” The preceding photo is one I took when I noticed the dragonfly; the following photo is one I took after slowly working my way into position for a better shot. Notice the dragonfly changed positions too, moving from one perch to another when I moved closer to her.

13 MAY 2021 | PNC. Wm. County, VA | Spangled Skimmer (teneral female)

This individual is a female, as indicated by her coloration and terminal appendages.

Copyright © 2021 Walter Sanford. All rights reserved.

Stream Cruiser dragonfly (female)

May 18, 2021

A Stream Cruiser dragonfly (Didymops transversa) was spotted during a recent photowalk with Michael Powell along a mid-size stream at an undisclosed location in Prince William County, Virginia USA.

This individual is a female, as indicated by her thick abdomen and terminal appendages.

13 MAY 2021 | Prince William County, VA | Stream Cruiser (female)

The female was perched in a large field near the same location where Mike Powell found a Stream Cruiser exuvia on 13 April 2021.

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

Another female Uhler’s Sundragon

May 7, 2021

Before we move on from the early spring species of odonates, here are a couple of photos of another one of several female Uhler’s Sundragon dragonflies (Helocordulia uhleri) that were spotted during a photowalk with Michael Powell along a mid-size stream at an undisclosed location in Prince William County, Virginia USA.

At first she wanted to play peek-a-boo.

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

After a while, both of us moved to a slightly different position that worked better for me to photograph the subject.

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

That reminds me of another one of my mantras for wildlife photography: Get a shot, any shot; refine the shot. In this case, that’s exactly what I did.

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

Common Whitetail dragonflies

May 4, 2021

Common Whitetail dragonfly (Plathemis lydia) was observed near a small pond during a photowalk with Michael Powell at Occoquan Regional Park (ORP). This individual is a female, as indicated by her mostly brown coloration, pattern of wing spots, and terminal appendages.

28 APR 2021 | ORP | Common Whitetail (female)

Contrast the appearance of the female (shown above) with an immature male (shown below) seen on the same day at the same location. Notice the wing spots and terminal appendages are quite different for female and male Common Whitetail dragonflies.

28 APR 2021ORP | Common Whitetail (immature male)

Later the same day, another Common Whitetail dragonfly was observed near Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR) in Fairfax County, Virginia USA. This individual is a mature male, as indicated by the white pruinescence covering his abdomen. “Common Whitetail,” the common name for Plathemis lydia, is derived from the coloration of mature males of this species.

28 APR 2021 | JMAWR | Common Whitetail (mature male)

Copyright © 2021 Walter Sanford. All rights reserved.

Uhler’s Sundragon dragonfly (emergent female)

April 27, 2021

Uhler’s Sundragon (Helocordulia uhleri) was spotted during a recent photowalk with Michael Powell along a mid-size stream at an undisclosed location in Prince William County, Virginia USA.

The dragonfly was perched on the exuvia from which it emerged; its cast skin was still clinging to a grass stem approximately six inches (6″) above the ground. The patch of grass was located two-to-three feet from the shoreline, where the stream current was slow-to-moderate. The stream bed was sandy and gently sloped near the site on land where the dragonfly larva stopped to eclose.

This individual is an emergent female, as indicated by her teneral appearance, rounded hind wings, terminal appendages, and subgenital plate.

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

The subgenital plate is located on the ventral side of the abdomen beneath segment eight.

Underneath Segment 8 there is either an ovipositor or a subgenital plate, depending upon the species [of dragonfly]. Both structures are for laying eggs and extend over Segment 9 and possibly beyond. Source Credit: Dragonflies of the North Woods, by Kurt Mead.

Remember that “Segment 8 and 9” refers to abdominal segments eight and nine (of 10), numbered from front to back.

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

The following graphic from Dragonflies and Damselflies of the East by Dennis Paulson shows the shape of the subgenital plate on our emergent female matches Uhler’s perfectly.

Graphic used with written permission from Dennis Paulson.

True Detective

Generally speaking, teneral odonates are more challenging to identify than most mature adult dragonflies and damselflies. Full disclosure: Neither Mike nor I were certain of the identity of the emergent female when we were shooting photographs in the field. “Shoot first and ask questions later” is one of my mantras for wildlife photography.

The most reliable way to identify odonate larvae to the species level is to rear them to maturity and emergence, that is, unless you’re fortunate to find a larva emerging in the field. Since an exuvia is essentially a nearly perfect shell of the last instar, it can be used to identify other specimens of the same species by pattern matching.

In this case, I used the exuvia to reverse-engineer the identity of the teneral dragonfly. Look closely at a lateral view of the exuvia, as shown in the following photo taken by Mike Powell. Notice there are dorsal hooks on abdominal segments seven, eight, and nine (S7-9). This distinctive field mark confirms the identity of the species as H. uhleri.

Photo used with written permission from Michael Powell.

Also notice Mike’s photo shows a clear view of the emergent female’s terminal appendages, as well as the subgenital plate on the underside of her abdomen.

How it all began, and ended.

The sky was almost completely overcast and it was cool and windy when I spotted the emergent female. Mike Powell and I observed the dragonfly for quite a while and there was little noticeable progress. According to Michael Boatwright, founder and administrator of the Virginia Odonata Facebook group, the process of emergence can take longer when the air temperature is cooler.

When the sky began clearing, Mike Powell and I decided to go to a nearby place where he had seen adult Uhler’s recently. Later the same day, we returned to the site of the emergent female; she was gone, so I collected the exuvia. I plan to publish a photo set of the exuvia in an upcoming blog post. To be continued.

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

Uhler’s Sundragon dragonfly (female)

April 20, 2021

Uhler’s Sundragon (Helocordulia uhleri) was spotted during a recent photowalk along a mid-size stream at an undisclosed location in Prince William County, Virginia USA.

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

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 the rounded hind wings and two cerci are visible clearly in the full-size version of the following photo.

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

Just the facts, ma’am.

According to records for the Commonwealth of Virginia maintained by Dr. Steve Roble, Staff Zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage, the adult flight period for H. uhleri is 29 March to 27 June. The species is classified as common. Its habitat is “streams.”

Bear in mind, Dr. Roble’s records are for the entire state, therefore the adult flight period for H. uhleri seems to be longer than it is in reality. The adult flight period for a single site is probably no more than a month, and more likely around two-to-three weeks. For example, according to records for Northern Virginia maintained by Kevin Munroe, former manager of Huntley Meadows Park, the adult flight period for Uhler’s is 11 April to 05 May.

It’s also worth noting that the window of opportunity to see Uhler’s Sundragon closes rapidly after trees are in full leaf; this phenological event usually occurs by mid-April in the mid-Atlantic USA.

Is Uhler’s Sundragon common? I guess the answer to that question depends upon where you live. In Northern Virginia, Kevin Munroe classified H. uhleri as “rare.” In fact, I’m aware of only one location in Northern Virginia where Uhler’s Sundragon can be found with reasonable certainty although not in large numbers.

Copyright © 2021 Walter Sanford. All rights reserved.


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