Fine-lined Emerald dragonfly redux (Part 2)

September 21, 2017

The same Fine-lined Emerald dragonfly (Somatochlora filosa) was photographed while it perched on grasses located in two shady places along one of the trails at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

This individual is a male, as indicated by his terminal appendages and prominent hamules.

Set 3

A busy background of thigh-high grasses made it challenging to find a pleasing composition.

Set 4

Photo Set 4 is my favorite, in terms of both quantity and quality. The dragonfly is shown perching on a grass stem that is estimated to be more than six feet high.

The next three photos are uncropped, that is, full-size images (4,000 x 3,000 pixels). This individual has a distinctive eye injury to the top of his left eye (facing forward) that enabled me to recognize the same male dragonfly is the subject in all four photo sets.

Did you notice the male Big Bluet damselfly (Enallagma durum) that photo-bombed the preceding image?

The last photo was cropped lightly in order to improve the composition, and Adobe Photoshop CC 2017 was used to remove a distracting element from the lower-right corner of the image.

Related Resources

Copyright © 2017 Walter Sanford. All rights reserved.

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Fine-lined Emerald dragonfly redux (Part 1)

September 19, 2017

Several Fine-lined Emerald dragonflies (Somatochlora filosa) were spotted during a photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

The same dragonfly was photographed while it perched in several shady places along one of the trails at the park. In my limited experience, Somatochlora filosa seems to prefer perching on bare tree branches or long stems of wild grass. Part 1 features two photo sets showing Fine-lined Emerald resting on other types of perches; Part 2 will feature two more photo sets showing the dragonfly perching on grasses.

This individual is a male, as indicated by his terminal appendages and prominent hamules.

Set 1

The first photograph is a strong contender for my Odonart Portfolio. I like the way the green vegatation complements the dragonfly’s emerald colored eyes. Can anyone identify the type of plant on which the dragonfly is perching?

Set 2

The second set of photos shows the dragonfly perching on a Common Milkweed (Asclepias syriaca) seed pod.

The next photo was taken a step-or-so closer…

This individual has a distinctive eye injury to the top of his left eye (facing forward).

And after a few side steps, I was able to take a good ventral-lateral shot.

Editor’s Note: Sincere thanks to several members of the Capital Naturalist Facebook group for identifying the species of milkweed plant shown in photo Set 2. “Capital Naturalist” is administered by Alonso Abugattas, Natural Resources Manager, Arlington County Parks, Virginia.

Related Resources

Copyright © 2017 Walter Sanford. All rights reserved.

Robber fly (female)

September 17, 2017

An unknown species of robber fly was spotted perching on a wooden post along Deephole Point Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. Notice its abdomen is two-thirds striped and one-third black, indicating this individual is a female.

10 SEP 2017 | Occoquan Bay NWR | robber fly (female)

Copyright © 2017 Walter Sanford. All rights reserved.

Black Saddlebags (terminal appendages)

September 15, 2017

Male and female Black Saddlebags dragonflies (Tramea lacerata) are somewhat similar in appearance. Terminal appendages can be used to identify gender.

Female

A female Black Saddlebags was spotted along Deephole Point Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

10 SEP 2017 | Occoquan Bay NWR | Black Saddlebags (female)

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

10 SEP 2017 | Occoquan Bay NWR | Black Saddlebags (female)

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

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”).

A male Black Saddlebags was spotted in the central wetland area at Huntley Meadows Park, Fairfax County, Virginia USA.

12 SEP 2014 | Huntley Meadows Park | Black Saddlebags (male)

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

Copyright © 2017 Walter Sanford. All rights reserved.

Fine-lined Emerald dragonflies (males)

September 13, 2017

Three Fine-lined Emerald dragonflies (Somatochlora filosa) were spotted during a long photowalk at Occoquan Bay National Wildlife Refuge. All three individuals are males, as indicated by their terminal appendages and prominent hamules.

If I have seen further it is by standing on the shoulders of giants. Source Credit: Sir Isaac Newton.

Sincere thanks to Jim Waggener, Wildlife Survey Coordinator, as well as other members of Jim’s survey group for sharing information that enabled me to find this rare to uncommon species of dragonfly. The group has surveyed four sites in Northern Virginia regularly for many years, including Occoquan Bay National Wildlife Refuge.

No. 1

Fine-lined Emerald dragonflies seem to prefer perching on bare tree branches or long stems of wild grass, typically at chest- or head-height although not exclusively. For example, this guy was perched about waist-high on a cluster of fallen tree branches.

10 SEP 2017 | Occoquan Bay NWR | Fine-lined Emerald (male)

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

Fine-lined Emerald seems to prefer perching in sun rather than shade, unlike Mocha Emerald (Somatochlora linearis) — another species from the Family Corduliidae (Emeralds) found in Northern Virginia that prefers shady places.

The following ventral-lateral shot shows the lines on the thorax for which this species is named.

10 SEP 2017 | Occoquan Bay NWR | Fine-lined Emerald (male)

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

No. 2

The male shown in the next photo is perched on a long grass stem, about chest-high. He posed for two shots, patrolled back-and-forth a few times, and then disappeared.

10 SEP 2017 | Occoquan Bay NWR | Fine-lined Emerald (male)

No. 3

The last male was the most cooperative model. The first photo was taken at a distance of approximately six feet.

10 SEP 2017 | Occoquan Bay NWR | Fine-lined Emerald (male)

The next photo was taken a step-or-so closer…

10 SEP 2017 | Occoquan Bay NWR | Fine-lined Emerald (male)

And after a few side steps, I was able to take a good lateral shot.

10 SEP 2017 | Occoquan Bay NWR | Fine-lined Emerald (male)

The Backstory

This might be one of those stories in which the take-away is “persistence pays dividends.”

I made two trips to Occoquan Bay NWR during Fall 2016 when Fine-lined Emerald was my target species. On 21 September 2016, I spotted one or more dragonflies (species unknown) patrolling the treetops along one of the trails at OBNWR. I didn’t see any signs of Fine-lined Emerald on 25 October 2016, consistent with records for late-date maintained by Kevin Munroe (04 October for Northern Virginia) and Dr. Steven Roble (15 October for the Commonwealth of Virginia).

In retrospect, I realized I started searching too late in the year during 2016 so I started earlier in 2017. My first trip to OBNWR was on 30 August 2017; it turned out to be fruitless. I hit the jackpot on 10 September 2017! Fine-lined Emerald is a new species for my life list of dragonflies.

Rare to Uncommon

A distribution map of official records for Fine-lined Emerald helps to illustrate its classification as a rare to uncommon species of odonate.

Source Credit: Abbott, J.C. 2006-2017. OdonataCentral: An online resource for the distribution and identification of Odonata. Available at http://www.odonatacentral.org. (Accessed: September 14, 2017).

Key: blue dots = Dot Map Project; green dots = Accepted records; yellow dots = Pending records.

Related Resources

Copyright © 2017 Walter Sanford. All rights reserved.

Springtime Darner (terminal appendages)

September 11, 2017

Male and female Springtime Darner dragonflies (Basiaeschna janata) are colored similarly sometimes. Terminal appendages can be used to identify gender.

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”).

A male Springtime Darner was spotted along a mid-size rocky stream located at Hemlock Overlook Regional Park (HORP), Fairfax County, Virginia USA.

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

Female

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

Female Springtime Darners are polymorphic: the spots on their abdomen are either blue (andromorphic) or green (heteromorphic); this female — spotted at a remote location in Huntley Meadows Park (HMP) — is a blue andromorph.

15 APR 2016 | HMP | Springtime Darner (female, blue andromorph)

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

Copyright © 2017 Walter Sanford. All rights reserved.

Late-season Swift Setwing dragonflies

September 9, 2017

Several Swift Setwing dragonflies (Dythemis velox) were spotted during a photowalk around Mulligan Pond, Jackson Miles Abbott Wetland Refuge (JMAWR), Fairfax County, Virginia USA.

05 SEP 2017 | JMAWR | Swift Setwing (mature male)

Both individuals featured in this post are mature males, as indicated by their terminal appendages, discolored abdomen, and tattered wings.

05 SEP 2017 | JMAWR | Swift Setwing (mature male)

05 SEP 2017 | JMAWR | Swift Setwing (mature male)

Adult Flight Period for Swift Setwing

Late-season Swift Setwing dragonflies,” the title of this blog post, implies that the adult flight period for this species in Northern Virginia is well known. It isn’t.

The Dragonflies of Northern Virginia Calendar of Flight Periods by Kevin Munroe, former manager at Huntley Meadows Park, doesn’t include Swift Setwing because the species was unknown to occur in Northern Virginia before it was discovered on 24 June 2016 in Fairfax County by my good friend Michael Powell. One year later, we’re still gathering data for this newcomer to the region.

The adult flight period for Swift Setwing in the Commonwealth of Virginia is from 20 June to 02 October, according to records maintained by Steven M. Roble, Ph.D., Staff Zoologist, Virginia Department of Conservation and Recreation, Division of Natural Heritage.

September is in fact late-season for Swift Setwing, based upon state records — a fact underscored by qualitative observations of the appearance of males photographed in early August and early September at the same location.

Post Update

I just realized Mike Powell spotted the First Swift Setwing in 2017 on 19 June 2017 at Mulligan Pond — a new early date for this species in Virginia!

Copyright © 2017 Walter Sanford. All rights reserved.

Pond pals

September 7, 2017

A male Eastern Amberwing dragonfly (Perithemis tenera) was spotted perching on the nose of a water turtle, possibly a Northern Red-bellied Cooter (Pseudemys rubriventris), at Mulligan Pond, Jackson Miles Abbott Wetland Refuge (JMAWR), Fairfax County, Virginia USA.

02 AUG 2017 | JMAWR | Eastern Amberwing (male) and water turtle

As soon as the turtle surfaced the dragonfly appeared out of thin air and landed on the turtle’s nose. I shot two photos before the turtle dove underwater and swam out of sight, but for a magical moment, the turtle and dragonfly were pond pals!

Editor’s Notes

Sincere thanks to Matt Ratcliffe, member of the Virginia Odonata Facebook group, for confirming my tentative identification of the water turtle. Now that the identity of the turtle is certain, I named the pair of pond pals Scooter and Cooter.

Copyright © 2017 Walter Sanford. All rights reserved.

Black Swallowtail (Papilio polyxenes)

September 5, 2017

Several Black Swallowtail butterflies (Papilio polyxenes) were spotted on 30 August 20017 during a photowalk along Deephole Point Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

The following individual is a male. All of the Black Swallowtails that I observed seemed to be quite skittish, including this guy. He flew away every time I approached him slowly. I noticed that he returned to nearly the same spot after a lot of fluttering around, so I moved to a position from which I could shoot his photo without moving.

108mm (600mm, 35mm equivalent) | ISO 100 | f/8 | 1/800s | -3 ev

Exposure Compensation

Exposure compensation is your friend when shooting high-contrast subjects like this Black Swallowtail. It is usually possible to pull detail from underexposed shadows. On the other hand, detail is lost when the highlights are “blown out.” What’s the solution? Expose for the shadows and use exposure compensation to capture detail in the highlights.

Related Resource: The exposure triangle and exposure compensation

Copyright © 2017 Walter Sanford. All rights reserved.

Big Bluet damselfly (mating pairs)

September 3, 2017

Hundreds, if not thousands, of Big Bluet damselflies (Enallagma durum) were spotted on 30 August 2017 during a photowalk along Deephole Point Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

A mating pair of Big Bluet was spotted “in heart.” The male is on the upper-right; the female on the lower-left.

30 AUG 2017 | OBNWR | Big Bluet (mating pair, “in heart“)

Big Bluet females are polymorphic, including a blue morph and brown morph. The female in this mating pair is a blue andromorph.

30 AUG 2017 | OBNWR | Big Bluet (mating pair, “in heart“)

I photographed the following male because he was perching at the right height for me to take the shot while standing. I took one photo before he flew to another perch, closer to the ground.

30 AUG 2017 | OBNWR | Big Bluet (male)

As it turns out, the single male led me to another mating pair of Big Bluet that I hadn’t noticed!

30 AUG 2017 | OBNWR | Big Bluet (mating pair, “in heart“)

The female in the preceding mating pair is a brown heteromorph. Color is a highly variable field marker, and describing color is subjective. In my experience, the heteromorph female Big Bluets native to Northern Virginia are light tan to light olive drab in color.

Copyright © 2017 Walter Sanford. All rights reserved.


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