Archive for the ‘Aperture’ Category

More Mocha males

July 20, 2018

Nearly two weeks after my last visit to Huntley Meadows Park in search of Mocha Emerald dragonfly (Somatochlora linearis), I revisited the small forested stream in search of Mocha exuviae.

No luck finding exuviae, but hey, I decided to make lemonade from lemons and photograph a couple of Mocha males that hung up near each other, especially since there were noticeably fewer S. linearis in contrast with my last trip to the site.

Male 1

Both individuals are male, as indicated by their “indented” hind wings and terminal appendages.

Male 2

Copyright © 2018 Walter Sanford. All rights reserved.

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Sable Clubtail (terminal appendages)

July 18, 2018

Male and female Sable Clubtail dragonflies (Stenogomphurus rogersi) were spotted recently in Fairfax County, Virginia USA.

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”). The epiproct for Sable Clubtail is essentially a wide plate with two prongs.

08 JUN 2018 | Fairfax County, VA | Sable Clubtail (male)

08 JUN 2018 | Fairfax County, VA | Sable Clubtail (male)

The hind wings of male clubtail dragonflies are “indented” near the body, as shown in the preceding photograph. In contrast, the hind wings of female clubtails are rounded (shown below).

Female

Female dragonflies have a pair of cerci (superior appendages) that have little or no function. The abdomen of female Sable Clubtails is noticeably thicker than males of the same species.

05 JUL 2018 | Fairfax County, VA | Sable Clubtail (female)

Copyright © 2018 Walter Sanford. All rights reserved.

Sable Clubtail dragonfly (female)

July 16, 2018

A Sable Clubtail dragonfly (Stenogomphurus rogersi) was spotted perched near a small stream located in Fairfax County, Virginia USA. This individual is a female, as indicated by her rounded hind wings and terminal appendages.

Female: Colored like male but a bit more yellow on abdomen, including fine dorsal lines on segments and prominent patches on edges of S8–9. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 6092-6093). Princeton University Press. Kindle Edition.

The first photo is the best shot from a set of “record shots,” that is, quick-and-dirty shots that provide a record of the spotting. As is. This is the first female Sable Clubtail that I have seen.

05 JUL 2018 | Fairfax County, VA | Sable Clubtail (female)

The next photo is my favorite in the set. Notice the tattered wings of this mature female — looks like she’s been working hard to perpetuate the small population of S. rogersi at this location!

05 JUL 2018 | Fairfax County, VA | Sable Clubtail (female)

The last photo provides a dorso-lateral view of the female.

05 JUL 2018 | Fairfax County, VA | Sable Clubtail (female)

New late date for Northern Virginia

The adult flight period for Sable Clubtail is from 08 June to 25 June (peaks in mid-June) according to records for Northern Virginia maintained by Kevin Munroe, former manager at Huntley Meadows Park. 05 July extends the old record by 10 days.

According to records for the Commonwealth of Virginia maintained by Dr. Steve Roble, a zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage, 21 May to 24 July is the adult flight period for S. rogersi.

Reproducing population

There is a small reproducing population of S. rogersi at this location, as evidenced by my spotting of a mature female and Dr. Edward Eder’s observation of a mating pair (in wheel) on 21 June 2018. Great catch, Ed!

Image used with permission from Dr. Edward Eder.

Copyright © 2018 Walter Sanford. All rights reserved.

Last man standing

July 14, 2018

One, possibly two Sable Clubtail dragonfly (Stenogomphurus rogersi) was/were spotted perched alongside a small stream located in Fairfax County, Virginia USA. All individuals featured in this photo set are male, as indicated by their indented hind wings and terminal appendages.

Male 1

The first shot is a “record shot,” that is, a quick-and-dirty shot that provides a record of the spotting. In this case, I was able to shoot one photo before Male 1 flew away. I didn’t see where he landed.

26 JUN 2018 | Fairfax County, VA | Sable Clubtail (male)

Male 2

I found Male 2 perched on overhanging vegetation along a nearby cut bank in the stream channel.

26 JUN 2018 | Fairfax County, VA | Sable Clubtail (male)

Notice the prominent peach-colored schmutz on the right forewing, located near the pterostigma, that is visible in both photos of Male 2. Since I don’t see the schmutz in the photo of Male 1, I think Male 1 and 2 are probably different individuals.

26 JUN 2018 | Fairfax County, VA | Sable Clubtail (male)

New late date?

Dr. Edward Eder and I visited the same site on the same day. Dr. Eder is one of the best all-around amateur naturalists I know. Ed saw/photographed a male Sable Clubtail near the same location as my photos, a little earlier in the day. Both of us thought we’d set a new late-date for S. rogersi in Northern Virginia. As it turns out, I spotted a female Sable Clubtail on 05 July 2018. Photos of the female will be featured in my next blog post.

Copyright © 2018 Walter Sanford. All rights reserved.

Gray on gravel

July 12, 2018

A Gray Petaltail dragonfly (Tachopteryx thoreyi) was spotted during a photowalk at Occoquan Regional Park, Fairfax County, Virginia USA.

This individual is a male, as indicated by his terminal appendages. He was perched on a gravel road, much to my surprise.

24 JUN 2018 | Occoquan Regional Park | Gray Petaltail (male)

This is the first Gray Petaltail that I’ve seen at the park since 04 June 2018, when I saw several individuals near a forested seep.

Copyright © 2018 Walter Sanford. All rights reserved.

Mocha male

July 10, 2018

The following photos show a Mocha Emerald dragonfly (Somatochlora linearis) perched alongside a small stream in the forest at a remote location in Huntley Meadows Park, Fairfax County, Virginia USA.

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

Mocha Emerald appears dark and featureless when viewed with the unaided eye in the shade of the forest canopy. More detail is revealed with added light from a fill flash.

Copyright © 2018 Walter Sanford. All rights reserved.

When Mocha flies

July 8, 2018

Many Mocha Emerald dragonflies (Somatochlora linearis) were spotted along a small stream in a remote location at Huntley Meadows Park (HMP), Fairfax County, Virginia USA. Most of the creek is shaded by the forest canopy — the perfect habitat for Mocha and mosquitos, a primary food source for all species of odonates.

05 JUL 2018 | HMP | Mocha Emerald (male, in flight)

Both individuals are male, shown hovering in flight above the water. Mocha Emerald males patrol back-and-forth along a short segment of the stream, stopping to hover in place sometimes.

05 JUL 2018 | HMP | Mocha Emerald (male, in flight)

Adult flight period

The adult flight period  for Mocha Emerald is from 16 June to 16 September (peaks in July-August), according to records for Northern Virginia maintained by Kevin Munroe, former manager at Huntley Meadows Park. In my experience, July is Mocha month in Northern Virginia.

According to records for the Commonwealth of Virginia maintained by Dr. Steve Roble, a zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage, 22 June to 10 October is the adult flight period for Mocha Emerald.

Copyright © 2018 Walter Sanford. All rights reserved.

Needham’s Skimmer dragonfly (female)

July 6, 2018

A Needham’s Skimmer dragonfly (Libellula needhami) was spotted during a photowalk at Occoquan Regional Park, Fairfax County, Virginia USA.

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

Female Needham’s 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.

The dragonfly was backlighted by the Sun. These photographs would have been impossible without the use of fill flash. Both photos are strong contenders for my Odonart Portfolio.

Copyright © 2018 Walter Sanford. All rights reserved.

Widow Skimmer dragonfly (immature male)

July 4, 2018

A Widow Skimmer dragonfly (Libellula luctuosa) was spotted during a photowalk at Occoquan Regional Park, Fairfax County, Virginia USA.

This individual is an immature male, as indicated by its coloration and terminal appendages. As a mature male, the front of his thorax and abdomen will be covered by white pruinescence.

Copyright © 2018 Walter Sanford. All rights reserved.

Later the same day…

July 2, 2018

Later the same day that I spotted my first-of-year Black-shouldered Spinyleg dragonfly (Dromogomphus spinosus) at Prince William Forest Park (PWFP), Prince William County, Virginia USA, I spotted another one during a photowalk at Occoquan Regional Park in Fairfax County, Virginia.

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

Adult flight period

The adult flight period for Black-shouldered Spinyleg is from 03 June to 12 September (peaks in July to August), according to records for Northern Virginia maintained by Kevin Munroe, former manager at Huntley Meadows Park. My earliest sighting is 21 June; my latest sighting is 08 August.

According to records for the Commonwealth of Virginia maintained by Dr. Steve Roble, a zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage, 08 May to 10 October is the adult flight period for Black-shouldered Spinyleg.

Copyright © 2018 Walter Sanford. All rights reserved.


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