Archive for June, 2019

Dromogomphus spinosus exuvia

June 28, 2019

A dragonfly exuvia was collected by Joe Johnston on 22 May 2019 at Aquia Creek, Stafford County, Virginia USA. This specimen is the cast skin from a Black-shouldered Spinyleg (Dromogomphus spinosus) larva. D. spinosus is a member of Family Gomphidae (Clubtails).

Black-shouldered Spinyleg (Dromogomphus spinosus) | exuvia (dorsal)

At first I thought the exuvia might be a species from the genus Stylurus, based upon the mid-dorsal spine on abdominal segment nine (S9). After careful examination of two excellent photo-illustrated PowerPoint presentations by Kevin Hemeon at NymphFest 2016 (see Related Resources, below), I noticed none of the species in the genus Stylurus have dorsal hooks. That’s when I realized the specimen must be D. spinosus. Eureka!

Related Resources

The following PowerPoint presentations by Kevin Hemeon are available in the “Files” section of the Northeast Odonata Facebook group. Direct links to the documents are provided below.

The Backstory

Joe Johnston is an avid boater and sport fisherman who kindly agreed to be my “Eyes on the Aquia,” always on the lookout for odonate exuvia to share with me. On 22 May 2019 Joe caught a largemouth bass that swam around one of the wooden pilings of a boat dock that extends far into Aquia Creek. The fishing line was snagged on the piling so Joe moved his boat into position to free the fish. That’s when he noticed the exuvia clinging to a piling on the underside of the dock. Good catches, Joe!

Tech Tips

The following equipment was used to shoot the quick-and-dirty handheld macro photograph featured in this post: Fujifilm X-T1 digital camera; and Fujinon XF80mm macro lens plus lens hood. The camera was set for both manual exposure and manual focus. That’s right, a switch on the camera body is used to set the type of focus. It’s a Fujifilm thing. Actually, back-button focus was used to autofocus the image and adjusted manually as necessary. That’s also a Fujifilm thing. Camera settings: focal length 80mm (120mm, 35mm equivalent); ISO 200; f/9; 1/180s.

Godox XProF radio flash trigger, mounted on the hotshoe of my X-T1, was used to control an off-camera Godox TT685 Thinklite TTL Flash (TT685F) set for radio slave mode. The flash was fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen the image, plus add annotations.

Sometime in the future (probably the odonate “off-season”) I will create higher quality composite images of this exuvia, shown from all viewpoints including the ventral view. As it turns out, the dorsal view is sufficient to identify this species.

Copyright © 2019 Walter Sanford. All rights reserved.

Black-shouldered Spinyleg (female)

June 26, 2019

A Black-shouldered Spinyleg dragonfly (Dromogomphus spinosus) 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 female, as indicated by her rounded hind wings and terminal appendages.

21 JUN 2019 | PNC. Wm. County, VA | Black-shouldered Spinyleg (female)

Notice the broad, mostly black stripe on the shoulder of her thorax, and large spines on the femur — two field marks from which the common name of this species is derived.

21 JUN 2019 | PNC. Wm. County, VA | Black-shouldered Spinyleg (female)

As this relatively young individual matures, its coloration will change from bright yellow to a dull shade of olive green similar to this mature male spotted at another location in Fairfax County, Virginia USA.

The dragonfly is perched on the broad green leaves of skunk cabbage (Symplocarpus foetidus) in both of the preceding photos.

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 very close to this cooperative subject!

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

An external flash unit was used for both photos featured in this post. Sometimes other wildlife photographers ask me why I prefer using flash for insect photography. See for yourself by looking at Mike Powell’s photo of the same subject, taken without flash. Although we were literally standing side-by-side when our photos were taken, the difference is striking. Mike’s photo shows the dim ambient light of the place where we photographed the dragonfly better than my photos; in contrast, I prefer to highlight the details of the subject.

Related Resource: Posts Tagged ‘Black-shouldered Spinyleg dragonfly’

Copyright © 2019 Walter Sanford. All rights reserved.

Dragonhunter (female)

June 24, 2019

A Dragonhunter dragonfly (Hagenius brevistylus) was spotted at South Fork Quantico Creek along “South Valley Trail,” Prince William Forest Park, Prince William County, Virginia USA.

21 JUN 2019 | Prince William Forest Park | Dragonhunter (female)

This individual is a female, although it is difficult to see some critical field marks from the viewpoint in the preceding photo. Thanks to Michael Boatwright, founder and administrator of the Virginia Odonata Facebook group, for confirming my tentative identification of the gender.

Copyright © 2019 Walter Sanford. All rights reserved.

Another Arrowhead Spiketail (female)

June 21, 2019

An Arrowhead Spiketail dragonfly (Cordulegaster obliqua) was spotted in a sunny clearing along a small-to-medium size forest stream at an undisclosed location in Prince William County, Virginia USA.

14 JUN 2019 | PNC. William County, VA | Arrowhead Spiketail (female)

This individual is a female, as indicated by her rounded hind wings, terminal appendages, and prominent ovipositor at the tip of her abdomen.

14 JUN 2019 | PNC. William County, VA | Arrowhead Spiketail (female)

Did you recognize the interrupted fern (Osmunda claytoniana) in the background of every photo in this gallery?

14 JUN 2019 | PNC. William County, VA | Arrowhead Spiketail (female)

The Backstory

Mike Powell and I stopped to use GPS to get a fix on our position at the end of a long photowalk that included lots of bushwhacking. We stopped because the small stream we were exploring was getting wider and deeper the farther we walked downstream, and we decided the stream habitat had changed to be less suitable for Sable Clubtail (S. rogersi), our target species.

The place where we stopped is a sunny meadow near the confluence of a tiny side stream with the larger stream we were following. As Mike was testing a few GPS apps for his Android cell phone, I noticed a big dragonfly as it flew down the tiny stream, turned left past us, and landed in the sunny meadow. I found the dragonfly after a few minutes of searching the area where I saw it land. I was hoping for a Tiger Spiketail (Cordulegaster erronea) but nonetheless delighted to see a female Arrowhead Spiketail — our second record of this species for the year at the remote location!

Related Resource: Arrowhead Spiketail dragonfly (female)

Copyright © 2019 Walter Sanford. All rights reserved.

Gray Petaltail dragonfly (male)

June 19, 2019

Gray Petaltail dragonflies (Tachopteryx thoreyi) have a well-known preference for perching on gray or tan colored surfaces, including gray or tan colored clothing.

Most of the photos of Gray Petaltail featured in my blog show them perched on gray/grayish surfaces. In contrast, the following Gray Petaltail is perched on a mostly tan colored tree.

21 MAY 2019 | PNC. William County, VA | Gray Petaltail (male)

This individual — spotted in a sunny clearing along a small forest stream at an undisclosed location in Prince William County, Virginia USA — is a male, as indicated by his “indented” hind wings, and terminal appendages.

The preceding 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 this cooperative subject!

Related Resource: Posts Tagged ‘Gray Petaltail dragonfly’

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.

Aurora Damsel (mating pair, in heart)

June 14, 2019

The mating pair of Aurora Damsel (Chromagrion conditum) shown in the following photograph is “in wheel,” in which the male uses “claspers” (terminal appendages) at the end of his abdomen to hold the female by her neck/thorax while they are joined at their abdomens. The male — blue, yellow, and black in color — is on top; the female — yellow and black in color — is on the bottom.

The copulatory, or wheel, position is unique to the Odonata, as is the distant separation of the male’s genital opening and copulatory organs. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 377-378). Princeton University Press. Kindle Edition.

The wheel position is sometimes referred to as “in heart” when damselflies mate.

04 JUN 2019 | PNC. William County, VA | Aurora Damsel (mating pair)

Female C. conditum is polymorphic, including two morphs: an andromorph with blue coloration similar to male; or a heteromorph with an entirely yellow thorax, as shown above.

It’s helpful to take photos of mating pairs of damselflies, especially “in wheel,” since males and females of the same species can look quite different.

Taxonomy

C. conditum is a monotypic genus in the Family Coenagrionidae (Narrow-winged Damselflies).

Copyright © 2019 Walter Sanford. All rights reserved.

Painted Skimmer dragonfly (female)

June 12, 2019

A Painted Skimmer dragonfly (Libellula semifasciata) was observed during a photowalk with my good friend Mike Powell along a small forest stream at an undisclosed location in Prince William County, Virginia USA.

04 JUN 2019 | PNC. William County, VA | Painted Skimmer (female)

This individual is a female, as indicated by her terminal appendages. Notice her right hind wing is slightly malformed near the body. It appears the wing failed to inflate completely during emergence. The malformation didn’t impair her ability to fly.

Did you recognize the interrupted fern (Osmunda claytoniana) in the background?

Copyright © 2019 Walter Sanford. All rights reserved.

“Grays” come in peace.

June 10, 2019

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

This individual is a male, as indicated by its “indented” hind wings and terminal appendages. The male is perched on the left sleeve of Mike’s gray “Army” logo t-shirt. I nicknamed this Gray “The Gripper” because Mike said he could feel the dragonfly tightening its grip on a small fold in the t-shirt.

“Grays”

If you look into the eyes of a Gray Petaltail dragonfly at close range, then you might agree with me that they look like the space aliens known as “Grays.” Hey, I’m just saying — Mike might have experienced a close encounter of the Gray kind!

Copyright © 2019 Walter Sanford. All rights reserved.

Eastern Copperhead

June 7, 2019

It’s almost inevitable: If you spend time in “Copperhead Country,” then you will see Copperheads. We do, and eventually we did.

An Eastern Copperhead (Agkistrodon contortrix) was observed during a photowalk with my good friend Mike Powell along a small forest stream at an undisclosed location in Prince William County, Virginia USA.

The first photo was taken as I peered cautiously over the edge of the fallen tree. I estimate the snake is approximately three feet long from head-to-tail — around the maximum size for this species.

04 JUN 2019 | PNC. William County, VA | Eastern Copperhead

The last photo shows a little closer zoom and crop on the snake.

04 JUN 2019 | PNC. William County, VA | Eastern Copperhead

Did you notice the fearless fly perched on the snake’s body?

The Backstory

Although it’s easy to see where Copperhead gets one of its many common names, it can be difficult to see them in some places in their natural habitat.

In this case, the snake was resting alongside a large fallen tree. Mike noticed the Copperhead after he crossed over the tree. Considering our remote location, we were very fortunate Mike didn’t step on the venomous snake.

See Eastern Copperhead for Mike Powell’s take on our close encounter of the Copperhead kind — it was both exciting and scary at the same time!

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.


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