Posts Tagged ‘Common Sanddragon dragonfly’

Another Common Sanddragon

July 10, 2019

Common Sanddragon dragonfly (Progomphus obscurus) was spotted by my good friend Mike Powell during a photowalk along a small stream in the forest at an undisclosed location in Prince William County, Virginia USA.

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

21 JUN 2019 | PNC. William County, VA | Common Sanddragon (male)

It’s possible the subject is the same male we saw a short distance upstream from this location.

21 JUN 2019 | PNC. William County, VA | Common Sanddragon (male)

Adult flight period

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 P. obscurus is from May 15 to September 19. The species is classified as common. Its habitat is “sandy streams.”

Bear in mind, Dr. Roble’s records are for the entire state, therefore the adult flight period for P. obscurus seems to be longer than it is in reality. The adult flight period for a single site is probably shorter — more likely around two months. For example, according to records for Northern Virginia maintained by Kevin Munroe, former manager of Huntley Meadows Park, the adult flight period for Commom Sanddragon is 29 May to 06 August.

Cut Banks and Sand Point Bars

Here’s a quick lesson on the geomorphology and basic hydrology of meandering streams, as it relates to odonates such as the Common Sanddragon that Mike and I observed along a small stream in the forest.

Streamflow is faster along cut banks and slower along sand point bars. As a result, erosion occurs along cut banks and deposition occurs along sand point bars.

P. obscurus — like the male featured in this post — can be found perching on sand point bars, usually facing the water.

Source Credit: The preceding image is a file from the Wikimedia Commons, United States Geological Survey.

Tech Tips

The first photo is uncropped, that is, full resolution for the Panasonic Lumix DMC-FZ300 superzoom bridge camera (4,000 x 3,000 pixels). Needless to say, I was fairly close to the subject!

The second photo is cropped in order to eliminate some distracting elements near the edges of the image.

Copyright © 2019 Walter Sanford. All rights reserved.

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Enter Sandman

July 1, 2019

Common Sanddragon dragonfly (Progomphus obscurus) was spotted by my good friend Mike Powell during a photowalk along a small forest stream at an undisclosed location in Prince William County, Virginia USA.

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

21 JUN 2019 | PNC. William County, VA | Common Sanddragon (male)

The Common Sanddragon is perched on a medium size fallen tree in the first photo, and on a boulder in the creek in the last photo. In both photos, the male is perched facing the water — presumably in search of a mate.

21 JUN 2019 | PNC. William County, VA | Common Sanddragon (male)

Related Resource: Metallica – Enter Sandman [Official Music Video]

Copyright © 2019 Walter Sanford. All rights reserved.

Common Sanddragon dragonfly (male)

June 17, 2019

A Common Sanddragon dragonfly (Progomphus obscurus) was spotted by my good friend Mike Powell during a photowalk along a small forest stream at an undisclosed location in Prince William County, Virginia USA.

I was standing in the creek looking toward the sandy shoreline where the Common Sanddragon was perching.

14 JUN 2019 | PNC. William County, VA | Common Sanddragon (male)

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

14 JUN 2019 | PNC. William County, VA | Common Sanddragon (male)

Both of the photos featured in this blog post are uncropped, that is, full resolution for the Panasonic Lumix DMC-FZ300 superzoom bridge camera (4,000 x 3,000 pixels).

Copyright © 2019 Walter Sanford. All rights reserved.

More composite images: P. obscurus exuvia

February 6, 2019

The following focus-stacked composite images show dorsal- and ventral views of the exuvia from a Common Sanddragon (Progomphus obscuruslarva that was collected and reared by Bob Perkins.

Here are some personal observations after examining the specimen carefully.

The front- and middle legs block the mentum (prementum). This specimen is a good candidate for rehydrating the exuvia and reposing its legs.

Related Resource: Composite image: Progomphus obscurus exuvia.

Tech Tips

Six (6) photos were used to create the first focus stack; seven (7) photos were used for the second. A single focus point was positioned over select anatomical features, working from back-to-front; photos were taken at each point of interest.

The following equipment was used to shoot all of the photographs for the two focus-stacked composite images, shown above: Canon EOS 5D Mark II digital camera, in manual mode; Kenko 20mm macro automatic extension tubeCanon EF100mm f/2.8L Macro lens (set for manual focus); and Canon MT-26EX-RT Macro Twin Lite set for “Master” mode, and several external flashes set for “Slave” mode including Canon 580 EX- and Canon 580EX II Speedlites and a Godox TT685C Thinklite TTL Flash fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.

Adobe Photoshop CC 2017 was used to create the focus-stacked composite images, as well as spot-heal and sharpen the final output.

Copyright © 2019 Walter Sanford. All rights reserved.

Composite image: Progomphus obscurus exuvia

February 4, 2019

The following focus-stacked composite image shows the exuvia from a Common Sanddragon (Progomphus obscurus) larva that was collected and reared by Bob Perkins.

I have 10s, maybe 100s, of Common Sanddragon exuviae in my collection, but have never seen one cleaner than this beautiful specimen. I didn’t realize P. obscurus larvae are so hairy!

Related Resource: More composite images: P. obscurus exuvia.

Tech Tips

11 photos were used to create the focus stack. A single focus point was positioned over select anatomical features, working from back-to-front; photos were taken at each point of interest.

The following equipment was used to shoot the preceding composite image: Canon EOS 5D Mark II digital camera, in manual mode; Canon MP-E 65mm Macro lens (set for f/11 at 3x); and Canon MT-26EX-RT Macro Twin Lite set for “Master” mode, and several external flashes set for “Slave” mode including Canon 580 EX- and Canon 580EX II Speedlites and a Godox TT685C Thinklite TTL Flash fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.

Auto power-off was disabled for the camera and all external flash units.

Adobe Photoshop CC 2017 was used to create the focus stack, as well as spot-heal and sharpen the final output.

Copyright © 2019 Walter Sanford. All rights reserved.

Common Sanddragon (male)

July 23, 2017

A Common Sanddragon dragonfly (Progomphus obscurus) was spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is a male, as indicated by his terminal appendages and “indented” hind wings.

Some people imagine the yellow markings along the abdomen look like small burning candles.

All of the photographs in this set are uncropped. Knee-high rubber boots enabled me to photowalk some segments the stream, allowing me to get close to the subject.

This guy was a cooperative model; he allowed me to photograph him from many viewpoints.

The water level was relatively high after recent heavy rainfall. As a result, there were fewer sandy “beaches” than usual along the stream. I speculate the dragonfly may have been more cooperative because he wasn’t going to abandon one of only a few available preferred places to perch.

It’s possible the right front leg (facing forward) is either malformed or injured. Although the male flew several short patrols, landing in different places, the leg was never fully extended.

Copyright © 2017 Walter Sanford. All rights reserved.

Common Sanddragon dragonfly (male)

March 29, 2017

As you might expect, Common Sanddragon dragonflies (Progomphus obscurus) commonly perch on the sandy banks of small woodland streams. Not this one!

A Common Sanddragon was spotted perching on the vegetation growing alongside a manmade concrete drainage ditch that flows into Dogue Creek, Wickford Park, Fairfax County, Virginia USA.

This individual is a male, as indicated by his terminal appendages. Like all male clubtail dragonflies, the hindwings of male Common Sanddragons are “indented” near the body. This distinctive field marker is shown well by the last photo in this gallery.

Copyright © 2017 Walter Sanford. All rights reserved.

When things go wrong

November 30, 2016

One week after I witnessed the miraculous metamorphosis of an emergent male Common Sanddragon dragonfly (Progomphis obscuris), I was reminded that a lot can go wrong during emergence. Like the old blues standard says…

When things go wrong, go wrong with you
It hurts me too.

An emergent nymph was spotted during a photowalk along Dogue Creek at Wickford Park. The nymph was in the same position hours later, so I’m sad to say the dragonfly was stuck in its exuvia.

Related Resource: Common Sanddragon dragonfly (emergent male), a blog post by Walter Sanford featuring a time-series of photographs documenting the metamorphosis of an emergent male Common Sanddragon dragonfly on 01 June 2016 at Wickford Park.

Copyright © 2016 Walter Sanford. All rights reserved.

Common Sanddragon dragonfly (male)

November 28, 2016

A Common Sanddragon dragonfly (Progomphus obscurus) was spotted during a photowalk along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is a male, as indicated by his coloration and terminal appendages.

Like all male clubtail dragonflies, the hindwings of male Common Sanddragons are “indented” near the body. This distinctive field marker is shown well by the first, fourth, and last photos in this gallery.

Half of the photographs in this set are full-frame, that is, uncropped. Like the next photo. Knee-high rubber boots enabled me to photowalk the stream channel, allowing me to get much closer to the subject. This guy is the second of at least five adult males I was able to photograph at close range during the outing.

Some people imagine the yellow markings along the abdomen look like small burning candles.

Copyright © 2016 Walter Sanford. All rights reserved.

A day at the beach

June 14, 2016

Two captions came to mind when I looked at the following photo.

  1. Hey Bob, let’s move to the beach. We won’t have to eat each other because of the free sand which is there. (There’s a joke in there somewhere!)
  2. If I don’t move, then maybe it won’t notice me/eat me.

Question is, which animal was in greater danger during this close encounter — the dragonfly or the spider? As I understand dragonfly feeding behavior, they catch prey by flying rather than crawling. So I’d say the dragonfly was in greater danger of being eaten by the spider than vice versa.

For those of you keeping score at home, neither the dragonfly nor the spider was harmed in the making of this photo. I don’t remember what caused the dragonfly to fly away, but it did so soon after this photo was taken.

Common Sanddragon dragonfly (Progomphus obscurus) was spotted during a photowalk along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is a male, as indicated by his terminal appendages. The spider appears to be some sort of fishing spider, but that’s an educated guess.

Copyright © 2016 Walter Sanford. All rights reserved.


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