Archive for the ‘natural science’ Category

Big Bluet damselfly (male)

September 25, 2020

A Big Bluet damselfly (Enallagma durum) was spotted during a photowalk with Michael Powell along Deephole Point Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

This individual — one of hundreds, if not thousands we saw while hunting for a rare to uncommon species of dragonfly — is a male, as indicated by his blue and black coloration and terminal appendages.

15 SEP 2020 | OBNWR | Big Bluet (male)

Ideal habitat for Big Bluet is as follows.

Habitat Large sandy lakes and lower reaches of rivers, even extending into brackish estuaries. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 2156-2157). Princeton University Press. Kindle Edition.

Think large, tidal rivers and bays. I have observed E. durum at Dyke Marsh Wildlife Preserve, Accotink Bay Wildlife Refuge, and Occoquan Bay National Wildlife Refuge.

Related Resources: Excellent digital scans created by Gayle and Jeanelle Strickland. Click on the button labeled “Download file” in order to view/save a full-size version of the graphics.

Sidebar: Scientific Classification of Damselflies

The following concise explanation of the scientific classification of damselflies is provided to help the reader understand where the genus Enallagma (American Bluets) fits into the bigger picture of the Order OdonataSuborder Zygoptera (Damselflies).

There are four families of damselflies in the United States of America, although only three families occur in the mid-Atlantic USA: Broad-winged damselflies; Narrow-winged damselflies (a.k.a., Pond Damselflies); and Spreadwing damselflies.

  1. Family Calopterygidae – Broad-winged Damselflies
  2. Family Coenagrionidae – Narrow-winged Damselflies
  3. Family Lestidae – Spreadwings

1. Family Calopterygidae is comprised of two genera.

2. Family Coenagrionidae is comprised of 14 genera. Three genera are common in Northern Virginia: Argia (Dancers); Enallagma (American Bluets); and Ischnura (Forktails).

3. Family Lestidae is comprised of two genera.

  • Archilestes (e.g., Great Spreadwing)
  • Lestes (e.g., Slender Spreadwing, Southern Spreadwing, Swamp Spreadwing)

There are relatively few genera of Broad-winged Damselflies and Spreadwing Damselflies. In contrast, there are many more genera and species of Narrow-winged Damselflies — more species, including many that look similar, makes this family the most challenging to learn!

Related Resource: “The Odonata of North America” is a complete list of both scientific names and common names for damselflies and dragonflies, maintained by the Dragonfly Society of the Americas.

Copyright © 2020 Walter Sanford. All rights reserved.

The old gray mare

September 23, 2020

A Great Blue Skimmer dragonfly (Libellula vibrans) was spotted during a photowalk with Michael Powell along Deephole Point Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

This individual is an old female, as indicated by her coloration and terminal appendages.

Oh the old gray mare
She ain’t what she used to be

Like a fine wine, she’s aged to perfection!

Copyright © 2020 Walter Sanford. All rights reserved.

I’d walk a mile for a Clubtail.

September 21, 2020

I would, and I did. Several miles, in fact.

Approximately 4 miles of gravel roads are reserved for foot traffic only. The wildlife drive is a one way, 2-mile loop. Source Credit: General brochure, Occoquan Bay National Wildlife Refuge.

It’s hard to believe there was a time in the United States of America that tobacco companies were allowed to advertise in both electronic- and print media. I was 12 years old when this “I’d walk a mile for a Camel” commercial was shown on broadcast television in 1966. Paraphrasing the TV commercial, “Clubtail hunters, you know what I mean. You other guys, start walking.”

Did I lose you with my little trip down memory lane? Like Camel cigarettes, I wouldn’t walk a mile for just any clubtail dragonfly. But for this relatively uncommon handsome devil, definitely!

The Backstory

Russet-tipped Clubtail dragonfly (Stylurus plagiatus) was spotted by Michael Powell during a long photowalk at Occoquan Bay National Wildlife Refuge. This individual is a male, as indicated by his “indented” hind wings and terminal appendages.

By the time I caught up to Mike, the somewhat skittish Russet-tipped Clubtail flew away. I thought I saw the dragonfly fly through an opening in a line of trees along a gravel road. I walked to the other side of the tree line to look for the elusive dragonfly, one of two target species for the day. Mike followed along behind me. Seeing nothing, I gave up too soon. Fortunately Mike was more persistent and rediscovered the Russet-tipped male farther along the backside of the treeline. This time, Mr. Skittish was a little more cooperative.

American Sweetgum

The dragonfly is perched on an American Sweetgum (Liquidambar styraciflua) tree. Thanks to Mike Boatwright and Drew Chaney for confirming my tentative identification based upon the distinctive shape of the tree leaves. Sweetgum leaves turn spectacular colors during fall (see Related Resources, below).

Related Resources

Copyright © 2020 Walter Sanford. All rights reserved.

Eastern Pondhawk dragonfly (female)

September 18, 2020

An Eastern Pondhawk dragonfly (Erythemis simplicicollis) was spotted during a photowalk with Michael Powell along Deephole Point Road at Occoquan Bay National Wildlife Refuge.

This individual is a female, as indicated by her green coloration and white terminal appendages.

15 SEP 2020 | OBNWR | Eastern Pondhawk (female)

Look closely at the full-size version of the preceding photo. Notice the subgenital plate, a black upside-down “shark fin” located beneath abdominal segment eight.

Underneath Segment 8 there is either an ovipositor or a subgenital plate, depending upon the species [of dragonfly]. Both structures are for laying eggs and extend over Segment 9 and possibly beyond. Source Credit: Dragonflies of the North Woods, by Kurt Mead.

Remember that “Segment 8 and 9” refers to abdominal segments eight and nine (of 10), numbered from front-to-back.

Related Resource: Eastern Pondhawk dragonflies, a photo-illustrated guide to the identification of male- and female terminal appendages.

Copyright © 2020 Walter Sanford. All rights reserved.

Tattered

September 16, 2020

18 AUG 2020 | JMAWR | Slaty Skimmer (male)

The preceding photo shows a Slaty Skimmer dragonfly (Libellula incesta) that was spotted during a photowalk with Michael Powell near Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR) in Fairfax County, Virginia USA.

This individual is a mature male, as indicated by his coloration, tattered wings, and terminal appendages.

Copyright © 2020 Walter Sanford. All rights reserved.

Blue Dasher dragonfly (male)

September 14, 2020

Ubiquitous. Yep, that’s Blue Dasher dragonfly (Pachydiplax longipennis).

18 AUG 2020 | JMAWR | Blue Dasher (male)

A male Blue Dasher was spotted during a photowalk with Michael Powell around Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR) in Fairfax County, Virginia USA.

Copyright © 2020 Walter Sanford. All rights reserved.

Common Whitetail dragonfly (mature male)

September 11, 2020

A Common Whitetail dragonfly (Plathemis lydia) was spotted during a photowalk with Michael Powell around Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR) in Fairfax County, Virginia USA.

This individual is a mature male, as indicated by his coloration, pattern of wing spots, and terminal appendages.

18 AUG 2020 | JMAWR | Common Whitetail (mature male)

Common Whitetail” is one of a few common names for odonates that makes perfect sense, at least for males. This species is found commonly in lentic habitats. It’s one of the first species to emerge during spring and one of the last to disappear in fall.

Although Common Whitetail is easy to find, it can be challenging to photograph mature males without blowing out the highlights in their bright white abdomen.

Copyright © 2020 Walter Sanford. All rights reserved.

Solanum carolinense wildflowers

September 9, 2020

I noticed some beautiful little wildflowers as I was photographing the Black and Yellow Argiope featured in my last blog post. Sometimes you need to stop and smell the “banana flowers.” Huh?

I maintain a simple text file called “Photowalking Field Notes.” After every photowalk or studio photo session, I record the date, location, photo gear, and of course, what I saw and photographed. Sometimes I see things that I’m unable to photograph (e.g., Tiger Spiketail dragonflies), so “saw” and “photographed” aren’t necessarily the same. Although I use keywords in both Apple Aperture and Adobe Lightroom, searchable text is a quick and easy way to find photos I have taken.

My field note for this photo is “light purple wildflower <– banana flower” because the yellow plant centers [insert correct name for plant anatomy here] remind me of a hand of bananas.

18 AUG 2020 | JMAWR | Solanum carolinense wildflowers

The preceding photo is simply a “record shot” of a wildflower I never noticed. I contacted “Plant Man Drew” Chaney for help with identification.

I met Drew at the Dragonfly Society of the Americas 2017 DSA Annual Meeting in Staunton, Virginia USA. Drew is an excellent all-around naturalist with considerable expertise in botany.

Drew quickly identified the wildflowers as Solanum carolinense. Most of the flowers in my photo appear a little past peak, based upon images featured on the reference Web page Drew provided. As always, thanks for your help, Drew — it is sincerely appreciated!

The Backstory

The wildflowers shown above were spotted during a photowalk with Michael Powell around Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR) in Fairfax County, Virginia USA.

Copyright © 2020 Walter Sanford. All rights reserved.

Black and Yellow Argiope (female)

September 7, 2020

While we’re doing that spider thing, here’s one that is seen commonly during late-summer/early-fall.

18 AUG 2020 | JMAWR | Black and Yellow Argiope (female)

A Black and Yellow Argiope (Argiope aurantia) spider was spotted during a photowalk with Michael Powell around Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR) in Fairfax County, Virginia USA. This individual is a female, as indicated by her size.

Females can be almost two inches long, while the males tend to be much smaller, rarely reaching even 1/4 of an inch in size. … The females live less than a year, dying by the first frosts. The males usually die right after breeding. Source Credit: Golden Garden Spider, by Alonso Abugattas, a.k.a, the Capital Naturalist.

Copyright © 2020 Walter Sanford. All rights reserved.

Stealthy spider stalks Swift Setwing

September 4, 2020

There I was, trying to create some Odonart©.

18 AUG 2020 | 12:02:18 PM | JMAWR | Swift Setwing (male)

As I “worked the shot,” the imaginary soundtrack in my mind reminded me of the music bed at the beginning of Bambi Meets Godzilla. Peaceful. And just as suddenly as the animated film ends rudely, the idyllic scene before my eyes took a turn for the ugly!

Cue the Jaws Theme Song as the walk-on music for a Long-jawed Orb Weaver.

18 AUG 2020 | 12:03:10 PM | JMAWR | Swift Setwing (male)

52 seconds of elapsed time could have been the difference between life and death for the dragonfly. As far as I know, the Swift Setwing survived this near-death experience.

The Backstory

Swift Setwing dragonfly (Dythemis velox) was spotted during a photowalk with Michael Powell around Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR) in Fairfax County, Virginia USA. This individual is a male, as indicated by his terminal appendages.

The first photo was taken when the dragonfly landed on a grass stem near the shoreline of the pond. Soon afterward his wings were “set” forward in the position from which the latter part of its common name is derived, as shown in the last photo. It is assumed by the author that the set wing position enables the dragonfly to take flight swiftly — a useful adaptation when being stalked by a stealthy spider!

Copyright © 2020 Walter Sanford. All rights reserved.


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