Blue Dasher dragonflies (immature males)

May 25, 2015

Blue Dasher dragonflies (Pachydiplax longipennis) display sexual dimorphism; terminal appendages may be used to differentiate immature males from females.

A Blue Dasher dragonfly (Pachydiplax longipennis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a young male.

14 MAY 2015 | Huntley Meadows Park | Blue Dasher (immature male)

This individual is an immature male, as indicated by its red eye color, partial pruinescence, and terminal appendages. When male Blue Dashers mature, their eyes are blue-green and their abdomen is completely blue except for the black tip.

A Blue Dasher dragonfly (Pachydiplax longipennis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a young male.

14 MAY 2015 | Huntley Meadows Park | Blue Dasher (immature male)

Some dragonflies, such as Blue Dasher, regulate their body temperature by perching in the “obelisk position”: the tip of the dragonfly’s abdomen is pointed toward the Sun, minimizing the surface area of the body exposed to direct heating by the Sun’s rays, thereby avoiding overheating.

A Blue Dasher dragonfly (Pachydiplax longipennis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a young male.

14 MAY 2015 | Huntley Meadows Park | Blue Dasher (immature male)

Another immature male was spotted at the same location about a week later.

A Blue Dasher dragonfly (Pachydiplax longipennis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a young male with a malformed wing.

22 MAY 2015 | Huntley Meadows Park | Blue Dasher (immature male)

Did you notice this individual has a malformed wing? A lot can go wrong when a dragonfly metamorphoses from a larva to an adult!

A Blue Dasher dragonfly (Pachydiplax longipennis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a young male with a malformed wing.

22 MAY 2015 | Huntley Meadows Park | Blue Dasher (immature male)

Copyright © 2015 Walter Sanford. All rights reserved.

Blue Dasher dragonfly (teneral female)

May 23, 2015

Blue Dasher dragonfly (Pachydiplax longipennis) was spotted during a photowalk at Huntley Meadows Park on 20 May 2015.

A Blue Dasher dragonfly (Pachydiplax longipennis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral female.

20 MAY 2015 | Huntley Meadows Park | Blue Dasher (teneral female)

This individual is a teneral female, as indicated by its coloration and terminal appendages. Notice the fragile appearance of her wings.

A Blue Dasher dragonfly (Pachydiplax longipennis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral female.

20 MAY 2015 | Huntley Meadows Park | Blue Dasher (teneral female)

She was sheltering close to the ground in the “drowned forest,” just beyond the end of the boardwalk.

A Blue Dasher dragonfly (Pachydiplax longipennis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral female.

20 MAY 2015 | Huntley Meadows Park | Blue Dasher (teneral female)

Contrast the appearance of the teneral female shown above with the following slightly more mature female spotted on the same day at a different location.

A Blue Dasher dragonfly (Pachydiplax longipennis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

20 MAY 2015 | Huntley Meadows Park | Blue Dasher (female)

Notice that her eye coloration is changing from red to blue as she matures. Also notice she is perching a few feet above the ground/water, the preferred height for Blue Dashers.

A Blue Dasher dragonfly (Pachydiplax longipennis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

20 MAY 2015 | Huntley Meadows Park | Blue Dasher (female)

Copyright © 2015 Walter Sanford. All rights reserved.

Blue Flag Iris

May 21, 2015

Man does not live by odonate alone. There, I said it. You may be thinking, “Oh no he didn’t. Blasphemer! Heretic!” I guess sometimes I need to channel my inner Cindy Dyer.

Blue Flag Iris (Iris virginica) is a perennial wildflower that can be found near the end of the boardwalk at Huntley Meadows Park, among many places at the park.

Blue Flag Iris (Iris virginica) spotted at Huntley Meadows Park, Fairfax County, Virginia USA.

14 MAY 2015 | Huntley Meadows Park | Blue Flag Iris (Iris virginica)

Iris was one of my mother’s favorite flowers, occupying a large part of her garden at the home where I grew up in Alexandria, Virginia. A belated but no less sincere “Happy Mother’s Day!” to you, Mom! Always thinking of you. Rest in peace.

Blue Flag Iris (Iris virginica) spotted at Huntley Meadows Park, Fairfax County, Virginia USA.

14 MAY 2015 | Huntley Meadows Park | Blue Flag Iris (Iris virginica)

Copyright © 2015 Walter Sanford. All rights reserved.

What’s my motivation?

May 19, 2015

True confession: I’ve struggled to stay motivated recently. The little voice inside my head kept asking, “Why do you endure long, difficult walks through chigger- and tick-infested vegetation, thorny vines, blood-thirsty mosquitos, hot and humid weather — all in pursuit of dragonflies and damselflies?”

Then I was reminded of the answer to my question: Sometimes Mother Nature gives me a glimpse of her awesome beauty. I enjoy sharing photographs of my good fortune, and I enjoy the opportunity for informal science education provided by my wildlife photography. I hope followers of my photoblog enjoy both looking at the photos and reading the related text!

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

14 MAY 2015 | Huntley Meadows Park | Painted Skimmer (female)

I spotted a single Painted Skimmer dragonfly (Libellula semifasciata) perching in a small meadow near a vernal pool.

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

14 MAY 2015 | Huntley Meadows Park | Painted Skimmer (female)

This individual is a female, as indicated by its terminal appendages. Female Painted 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.

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

14 MAY 2015 | Huntley Meadows Park | Painted Skimmer (female)

I’m especially fond of head-tilts in which the individual seems to display some of its personality.

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

14 MAY 2015 | Huntley Meadows Park | Painted Skimmer (female)

I worked the shot until my stunningly beautiful model …

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

14 MAY 2015 | Huntley Meadows Park | Painted Skimmer (female)

… decided the photoshoot was finished and flew high into the nearby trees.

A Painted Skimmer dragonfly (Libellula semifasciata) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

14 MAY 2015 | Huntley Meadows Park | Painted Skimmer (female)

Please look at the full-size version of the preceding photos in order to see the exquisite coloration of this dragonfly.

Copyright © 2015 Walter Sanford. All rights reserved.

Swamp Darner dragonfly (female)

May 17, 2015

Dragonflies are classified as either “fliers” or “perchers,” based upon their feeding habits. Swamp Darner dragonflies (Epiaeschna heros) are fliers; it is uncommon to see them perching.

A Swamp Darner dragonfly (Epiaeschna heros) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

15 MAY 2015 | Huntley Meadows Park | Swamp Darner (female)

This individual is a female, as indicated by her terminal appendages. She was perching near a vernal pool, probably resting after egg-laying (oviposition).

A Swamp Darner dragonfly (Epiaeschna heros) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

15 MAY 2015 | Huntley Meadows Park | Swamp Darner (female)

Please look at the full-size version of both photos in order to see the exquisite coloration of this dragonfly.

Related Resources: Digital Dragonflies, presenting high-resolution digital scans of living dragonflies.

  • Genus Epiaeschna | Epiaeschna heros | Swamp Darner | female | top view
  • Genus Epiaeschna | Epiaeschna heros | Swamp Darner | female | side view
  • Genus Epiaeschna | Epiaeschna heros | Swamp Darner | male | top view
  • Genus Epiaeschna | Epiaeschna heros | Swamp Darner | male | side view

Copyright © 2015 Walter Sanford. All rights reserved.

Phishing snakes

May 15, 2015

The following photos show one or more Northern Watersnakes (Nerodia sipedon sipedon) spotted during photowalks along the boardwalk in the hemi-marsh at Huntley Meadows Park in mid-September 2014.

What do you see when you look at the following photos? I think most people would say they see a snake lying on a log, sunning itself. Now look more closely at the full-size versions of each photo — there’s more than meets the eye!

Several fish are visible in the water. Notice most of the fish are located under the log. Like all animals, fish need food and shelter in order to survive. Many species of fish prefer to find a holding place that provides shelter, such as the log, and look for food as it passes their safe spot.

Northern Watersnake (Nerodia sipedon sipedon)

15 September 2014

Over a period lasting several days, I observed one or more snakes hunting fish at the same location. The snake would lie perfectly still on top of the log; as soon as the fish were lulled into a false sense of security, the snake would slip into the water suddenly and snag an unsuspecting fish. The same thing happened again and again, so I’m guessing the snake(s) figured out a good strategy for finding food easily.

Northern Watersnake (Nerodia sipedon sipedon)

15 September 2014

A few days later, there were noticeably fewer fish hiding below the log. Can you say “overfishing?”

Northern Watersnake (Nerodia sipedon sipedon)

19 September 2014

Copyright © 2015 Walter Sanford. All rights reserved.

Southern Spreadwing damselfly (male)

May 13, 2015

Southern Spreadwing damselfly (Lestes australis) was spotted perching on vegetation in a vernal pool at Huntley Meadows Park. This individual is a male, as indicated by its coloration and terminal appendages.

Copyright © 2015 Walter Sanford. All rights reserved.

Damselfly terminal appendages (male)

May 11, 2015

All male damselflies have four terminal appendages, collectively called “claspers.” Male damselfly terminal appendages don’t look exactly the same for all species of damselflies, but their function is identical.

Claspers are used to grab and hold female damselflies during mating: an upper pair of cerci (“superior appendages”) and a lower pair of paraprocts (“inferior appendages”).

Damselflies, including the larger members of the Spreadwing Family, are smaller than dragonflies. Please look at the full-size version of each annotated image in order to see critical details that cannot be seen in the preceding thumbnail versions.

For example, the first image shows the male hamules, …

paired structures that project from pocket under the second segment and hold female abdomen in place during copulation. Source Credit: Glossary [of] Some Dragonfly Terms, by Dennis R. Paulson.

The hamules are key field markers for differentiating some species of similar-looking damselflies, such as Southern Spreadwing (Lestes australis) and Sweetflag Spreadwing (Lestes forcipatus).

Related Resource: Dragonfly terminal appendages (male, female) [Painted Skimmer]

Copyright © 2015 Walter Sanford. All rights reserved.

Post update: Malformed odonates

May 9, 2015

All odonates, that is dragonflies and damselflies, have four wings. The following Common Green Darner dragonfly (Anax junius) has a malformed wing: one of its two hind wings didn’t expand to full-size during emergence.

Common Green Darner dragonfly (male, malformed wing)

28 APR 2015 | HMP | Common Green Darner (male, malformed wing)

This individual is a male, as indicated by its coloration and terminal appendages. The terminal appendages are shown more clearly in the next photo than the preceding one.

Common Green Darner dragonfly (male, malformed wing)

28 APR 2015 | HMP | Common Green Darner (male, malformed wing)

I’ve seen this guy two times during recent visits to a vernal pool at Huntley Meadows Park (HMP). I call him “3.75,” in reference to the number of wings he has. Like other Common Green Darners, “3.75” is able to fly and hawk smaller flying insects; he stops to rest more frequently than other darners, perhaps because he has to work harder to fly than he would if he had four fully-formed wings.

A lot can go wrong when a dragonfly metamorphoses from a larva to an adult. I’m surprised more odonates aren’t malformed, although the ones with fatal flaws probably tend to be uncommon sightings.

Related Resources:

Copyright © 2015 Walter Sanford. All rights reserved.

Painted Skimmer dragonfly (male)

May 7, 2015
Painted Skimmer dragonfly (male)

28 APR 2015 | Huntley Meadows Park | Painted Skimmer (male)

This is the second Painted Skimmer dragonfly (Libellula semifasciata) I’ve seen in 2015 at Huntley Meadows Park. Coincidentally this individual is another male, as indicated by its terminal appendages. Unlike the first one of the year that was spotted deep in the forest, this specimen was seen near a vernal pool in a small meadow.

It seems like the early-season Painted Skimmers are super skittish — five snaps and he was gone, similar to the first one!

Painted Skimmer dragonfly (male)

28 APR 2015 | Huntley Meadows Park | Painted Skimmer (male)

Copyright © 2015 Walter Sanford. All rights reserved.


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