Archive for October, 2017

Like a bad guest at a party

October 31, 2017

Common Whitetail dragonflies (Plathemis lydia) are like bad guests at a party — they are among the first odonates to arrive in spring and among the last to leave in fall. Unlike bad guests, it’s good to see Common Whitetails after a long, cold winter and you have to admire the fact that they survived a long, hot summer.

22 OCT 2017 | HMP | Common Whitetail (mature female)

The preceding photograph shows a Common Whitetail dragonfly that was spotted near a vernal pool at a remote location in Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a mature female, as indicated by her terminal appendages and pattern of wing spots.

Copyright © 2017 Walter Sanford. All rights reserved.

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Quick and dirty macro photos (Part 2)

October 29, 2017

A mating pair of Autumn Meadowhawk dragonflies (Sympetrum vicinum) was spotted on 25 October 2017 during a photowalk along the boardwalk in the central wetland area at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is “in wheel.” The female is the primary subject; the tip of the male’s red abdomen is the secondary subject.

The first photo is my favorite in the set.

ISO 100 | 56mm (~300mm, 35mm equivalent) | f/4.1 | 1/800s | -1 ev

All odonates (dragonflies and damselflies) have a 10-segmented abdomen, numbered from front to back. Notice the small black “rivets” around the joint between segments seven and eight (S7, S8) of the male’s abdomen. Does anyone know the function of these structures?

ISO 100 | 56mm (~300mm, 35mm equivalent) | f/4.1 | 1/800s | -1 ev

Each compound eye has approximately 30,000 ommatidia!

ISO 100 | 56mm (~300mm, 35mm equivalent) | f/4.1 | 1/800s | -1 ev

Tech Tips

The photographs in this gallery were taken using my Panasonic Lumix DMC-FZ150 superzoom digital camera set for ~12x zoom, Raynox DCR-250 close-up filter, and Canon 580EX Speedlite external flash (manual mode). The close-up filter screws onto the front of the camera lens using a 52-43mm step-down ring.

I estimate the “working distance” between the camera and subject was approximately three-to-six inches (~3-6″). I attempted to photograph several mating pairs of Autumn Meadowhawks; this is the only pair that allowed me to get close enough to shoot some macro photos.

Related Resource: Quick and dirty macro photos (Part 1), a blog post by Walter Sanford featuring photos of male Autumn Meadowhawk dragonflies.

Copyright © 2017 Walter Sanford. All rights reserved.

Quick and dirty macro photos (Part 1)

October 27, 2017

Several Autumn Meadowhawk dragonflies (Sympetrum vicinum) were spotted on 25 October 2017 during a photowalk along the boardwalk in the central wetland area at Huntley Meadows Park, Fairfax County, Virginia USA. All of these individuals are male.

The photographs in this gallery were taken using my Panasonic Lumix DMC-FZ150 superzoom digital camera set for ~12x zoom, Raynox DCR-250 close-up filter, and Canon 580EX Speedlite external flash (manual mode). I estimate the “working distance” between the camera and subject was approximately three-to-six inches (~3-6″). Now that’s what I call cooperative models!

ISO 100 | 56mm (~300mm, 35mm equivalent) | f/4.1 | 1/800s | -1 ev

The following photo is my favorite in the set.

ISO 100 | 56mm (~300mm, 35mm equivalent) | f/4.1 | 1/800s | -1 ev

Each compound eye has approximately 30,000 ommatidia!

ISO 100 | 56mm (~300mm, 35mm equivalent) | f/4.1 | 1/800s | -1 ev

The Raynox DCR-250 close-up filter is a relatively inexpensive solution that enables my Panasonic superzoom digital camera to be used for macro photography. Set-up is quick and easy — the filter simply screws onto the front of the camera lens using a 52-43mm step-down ring.

As you can see, depth-of-field is very shallow, caused in part by shooting in Shutter Priority mode rather than Aperture Priority. A cooperative subject, good light, and a lot of patience are essential for success.

Related Resource: Quick and dirty macro photos (Part 2), a blog post by Walter Sanford featuring photos of a mating pair of Autumn Meadowhawk dragonflies (in wheel).

Copyright © 2017 Walter Sanford. All rights reserved.

Polymorphism or old age?

October 25, 2017

Some species of female odonates are polymorphic, meaning females can be one of two or more colors. In contrast, some species of female odonates become discolored with age.

The thorax and abdomen of female Autumn Meadowhawk dragonflies (Sympetrum vicinum) can be either tan or red. The difference in color is the result of either polymorphism or age-related discoloration. More research is required to establish cause and effect.

Several tan and red female Autumn Meadowhawks were spotted during a recent photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

Tan

This individual is a tan female, as indicated by her terminal appendages and noticeably thicker abdomen than males of the same species.

Red

The following individuals are red females.

Copyright © 2017 Walter Sanford. All rights reserved.

Blue-faced Meadowhawk (Batch 4)

October 23, 2017

Batch 4 (of 4). Please look at the full-size version of each photo.

Several male Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) were spotted near a vernal pool at a remote location in Huntley Meadows Park, Fairfax County, Virginia USA.

The first photograph is my favorite in this batch; the second photo is, well, a close second place.

Related Resources

Copyright © 2017 Walter Sanford. All rights reserved.

Blue-faced Meadowhawk (Batch 3)

October 21, 2017

This gallery features photos from Batch 3 (of 4) showing male Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted during a recent photowalk around a vernal pool at a remote location in Huntley Meadows Park, Fairfax County, Virginia USA.

Here’s looking at you, kid.

The last photograph is my favorite in this batch.

Related Resources

Copyright © 2017 Walter Sanford. All rights reserved.

Heaven on Earth?

October 19, 2017

Did I find Heaven on Earth? All signs point to yes!

17 OCT 2017 | Webb Nature Sanctuary | NOVA Parks

17 OCT 2017 | Webb Nature Sanctuary | NOVA Parks

Well, maybe. Time will tell. All I know now is I didn’t see any dragonflies anywhere along the trails at Webb Nature Sanctuary, Clifton, Virginia USA on 17 October 2017, my first visit to the park.

As odonate hunting season is winding down I’m transitioning into “exploration mode,” when I check out new places while the weather is still relatively mild.

Getting oriented

The following map is located at the trail head.

17 OCT 2017 | Webb Nature Sanctuary | NOVA Parks

Margaret’s Branch, located along Fern Valley Trail, is a small stream that might provide good habitat for lotic species of dragonflies such as clubtails and spiketails.

Popes Head Creek is known to provide good habitat for many species of odonates, including Fawn Darner dragonfly and Dusky Dancer damselfly, to name a couple of fall species.

17 OCT 2017 | Webb Nature Sanctuary | NOVA Parks

R. Randolph Buckley Park (also known as Eight-Acre Park) is located on the opposite side of Popes Head Creek from Webb Nature Sanctuary. Buckley Park can be accessed via a footbridge across Popes Head Creek.

Related Resource: Lentic and lotic, a blog post by Walter Sanford.

Copyright © 2017 Walter Sanford. All rights reserved.

More Blue-faced Meadowhawk

October 17, 2017

Batch 2 (of 4). Please look at the full-size version of each photo.

Several male Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) were spotted near a vernal pool at a remote location in Huntley Meadows Park, Fairfax County, Virginia USA.

The last photograph is my favorite in this batch. Which photo is your favorite?

Related Resource: Blue-faced Meadowhawk dragonflies [Batch 1].

Copyright © 2017 Walter Sanford. All rights reserved.

Great Spreadwing (practice oviposition)

October 15, 2017

This gallery — named “practice oviposition” (egg-laying) — features a six-photo time series of a female Great Spreadwing damselfly (Archilestes grandis).

Female Great Spreadwing damselflies, like all female odonates, have two cerci (sing. cercus), superior appendages that have little or no function. Also notice two styli (sing. stylus), structures that serve as sensors (like “curb feelers“) in egg positioning during oviposition.

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

The female uses her styli to guide the ovipositor into position, as shown in the next two photos.

In this case, I saw no evidence that the ovipositor actually penetrated the tree twig. I think this was a practice run in preparation for the real thing, as the title of this blog post says.

Copyright © 2017 Walter Sanford. All rights reserved.

Great Spreadwing damselfly (female)

October 13, 2017

A Great Spreadwing damselfly (Archilestes grandis) was spotted near a vernal pool at a remote location in Huntley Meadows Park, Fairfax County, Virginia USA.

This individual is a female, as indicated by her terminal appendages and external reproductive anatomy, including two styli and an ovipositor.

Sometimes I struggle to choose between two similar images, so I decided to post both photos.

The following photo captured the “feel” of the morning light especially well.

The next two photos are among my favorites in this set.

This female was a more cooperative model after she moved to a perch on a man-made brush pile that provides habitat and shelter for many types of animals.

Female Great Spreadwing damselflies, like all female odonates, have two cerci (sing. cercus), superior appendages that have little or no function. Also notice two styli (sing. stylus), structures that serve as sensors (like “curb feelers“) in egg positioning during oviposition.

My next blog post will feature a six-photo time series that I named “practice oviposition” (egg-laying).

Copyright © 2017 Walter Sanford. All rights reserved.


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