Deadly Cobras!

August 29, 2016

Several Cobra Clubtail dragonflies (Gomphus vastus) were spotted during a photowalk along the Potomac River at Riverbend Park, Fairfax County, Virginia USA.

Cobra Clubtail seems to be a voracious predator. Three individuals were observed eating smaller insects.

Male 1

The first individual is a male, as indicated by his terminal appendages. He is eating a Crane Fly.

Male 2

Another male was observed eating a small butterfly, possibly an Eastern Tailed-blue (Cupido comyntas).

Female

The last individual is a female, as indicated by her terminal appendages and the rounded shape of its hind wings. She is eating an unknown species of damselfly (female).

Copyright © 2016 Walter Sanford. All rights reserved.

Everyone’s gotta eat!

August 27, 2016

Several Eastern Ringtail dragonflies (Erpetogomphus designatus) were spotted during photowalks along the Potomac River at Riverbend Park.

Eastern Ringtail seems to be a voracious predator, based upon an admittedly small sample size. Two individuals were observed eating smaller insects.

Male

The first individual is a male, as indicated by his terminal appendages; he is feeding upon an unknown black winged insect.

Female

The last individual is a female, as indicated by her terminal appendages; she is eating an unknown species of damselfly.

Almost gone, except for several legs!

Editor’s Note: The title of this post is an homage to Laura Lecce, a regular reader of my photoblog. Thanks for the inspirational comment on one of my previous posts, Laura!

Copyright © 2016 Walter Sanford. All rights reserved.

CalicOdonart

August 25, 2016

This post is a retrospective look at a few Odonarty photographs of two male Calico Pennant dragonflies (Celithemis elisa) spotted in mid-June 2016.

A Calico Pennant dragonfly (Celithemis elisa) spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is a male.

18 JUN 2016 | OBNWR | Calico Pennant (male)

Both males were photographed at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge (OBNWR), Prince William County, Virginia USA.

A Calico Pennant dragonfly (Celithemis elisa) spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is a male.

18 JUN 2016 | OBNWR | Calico Pennant (male)

A Calico Pennant dragonfly (Celithemis elisa) spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is a male.

18 JUN 2016 | OBNWR | Calico Pennant (male)

Copyright © 2016 Walter Sanford. All rights reserved.

Powdered Dancer (males, female)

August 23, 2016

Several Powdered Dancer damselflies (Argia moesta) were spotted during two photowalks along the Potomac River at Riverbend Park. Powdered Dancer is a new species on my life list of odonates.

Male

This individual is a male, as indicated by its coloration. The common name “Powdered” seems to perfectly describe the appearance of males of this species.

A Powdered Dancer damselfly (Argia moesta) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

04 AUG 2016 | Riverbend Park | Powdered Dancer (male)

Female

The following individual is a female, as indicated by its coloration. Female Powdered Dancers are polymorphic: this is the tan morph; there is also a blue morph that looks somewhat similar to males of the same species.

A Powdered Dancer damselfly (Argia moesta) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female (light brown morph).

04 AUG 2016 | Riverbend Park | Powdered Dancer (female)

Also notice the female’s abdomen is thicker near the tip than the tip of the male’s abdomen, due to female egg-laying anatomy.

A Powdered Dancer damselfly (Argia moesta) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female (light brown morph).

04 AUG 2016 | Riverbend Park | Powdered Dancer (female)

More males

Many more male Powdered Dancer damselflies were spotted during a follow-up photowalk on 08 August 2016.

A Powdered Dancer damselfly (Argia moesta) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

08 AUG 2016 | Riverbend Park | Powdered Dancer (male)

A Powdered Dancer damselfly (Argia moesta) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

08 AUG 2016 | Riverbend Park | Powdered Dancer (male)

A Powdered Dancer damselfly (Argia moesta) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

08 AUG 2016 | Riverbend Park | Powdered Dancer (male)

Sidebar: Scientific Classification of Damselflies

The following concise explanation of the scientific classification of damselflies is provided to help the reader understand where Argia (Dancers) fit into the bigger picture of the Order OdonataSuborder Zygoptera (Damselflies).

There are five 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.

Family Calopterygidae is comprised of two genera.

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

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!

Editor’s Note: Please comment to let me know whether the preceding information is helpful.

Related Resources:

Copyright © 2016 Walter Sanford. All rights reserved.

American Rubyspot damselflies

August 21, 2016

American Rubyspot (Hetaerina americana) is a member of the Family Calopterygidae (Broad-winged damselflies). They are common from May to October along rocky streams with riffles, such as the Potomac River at Riverbend Park.

Female

Female American Rubyspots are quite variable in appearance. The following specimen has a metallic green thorax and dark-colored abdomen; its wings feature a color gradient from red at the base to diffuse reddish-orange at the wing tips.

An American Rubyspot damselfly (Hetaerina americana) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female.

04 AUG 2016 | Riverbend Park | American Rubyspot (female)

The following annotated image illustrates some of the reproductive anatomy of a female American Rubyspot: two cerci (sing. cercus), superior appendages that have little or no function; and two styli (sing. stylus), structures that serve as sensors in egg positioning.

An American Rubyspot damselfly (Hetaerina americana) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female.

04 AUG 2016 | Riverbend Park | American Rubyspot (female)

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

Male

Male American Rubyspots have a metallic red thorax and dark-colored abdomen; its wings feature well-defined ruby-colored spots at the base. I was so focused on photographing the deep red wing spots that I forgot to shoot a dorsal view of the terminal appendages!

An American Rubyspot damselfly (Hetaerina americana) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

08 AUG 2016 | Riverbend Park | American Rubyspot (male)

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

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”).

Copyright © 2016 Walter Sanford. All rights reserved.

More Eastern Ringtail dragonflies

August 19, 2016

One female and two male Eastern Ringtail dragonflies (Erpetogomphus designatus) were spotted during a follow-up photowalk along the Potomac River at Riverbend Park.

Female and male Eastern Ringtail are somewhat similar in appearance. Terminal appendages, the shape of their hind wings, and the relative size of their club are good field markers to differentiate specimens by gender.

Female

The first individual is a female, as indicated by her terminal appendages. Female dragonflies have a pair of cerci (superior appendages) that have little or no function.

An Eastern Ringtail dragonfly (Erpetogomphus designatus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female.

08 AUG 2016 | Riverbend Park | Eastern Ringtail (female)

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

The preceding dorsal view of the dragonfly shows its hind wings are rounded near the body, a good field marker for female clubtail dragonflies. In contrast, the hind wings of male clubtails are “indented.” Also notice the female “club” is slightly smaller than the male club, as shown in the following photos.

Male 1

The male’s abdomen is slightly thinner (shown below); the female’s abdomen is slightly thicker (shown above).

An Eastern Ringtail dragonfly (Erpetogomphus designatus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

08 AUG 2016 | Riverbend Park | Eastern Ringtail (male)

Male 2

Male dragonflies have three terminal appendages, collectively called “claspers,” that are used to grab and hold female dragonflies during mating: an upper pair of cerci (“superior appendages”); and a lower unpaired epiproct (“inferior appendage”).

An Eastern Ringtail dragonfly (Erpetogomphus designatus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male, perching in the obelisk position.

08 AUG 2016 | Riverbend Park | Eastern Ringtail (male)

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

Notice the male’s hind wings are “indented” near the body, as shown in the last two photos.

An Eastern Ringtail dragonfly (Erpetogomphus designatus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

08 AUG 2016 | Riverbend Park | Eastern Ringtail (male)

An Eastern Ringtail dragonfly (Erpetogomphus designatus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

08 AUG 2016 | Riverbend Park | Eastern Ringtail (male)

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

  • Genus Erpetogomphus | Erpetogomphus designatus | Eastern Ringtail | female | top view
  • Genus Erpetogomphus | Erpetogomphus designatus | Eastern Ringtail | female | side view
  • Genus Erpetogomphus | Erpetogomphus designatus | Eastern Ringtail | male | top view
  • Genus Erpetogomphus | Erpetogomphus designatus | Eastern Ringtail | male | side view

Copyright © 2016 Walter Sanford. All rights reserved.

More Black-shouldered Spinyleg dragonflies

August 17, 2016

Another female and male Black-shouldered Spinyleg dragonfly (Dromogomphus spinosus) were spotted during a follow-up photowalk along the Potomac River at Riverbend Park.

Female and male Black-shouldered Spinyleg are somewhat similar in appearance. Terminal appendages, the shape of their hind wings, and the relative size of their club are good field markers to differentiate specimens by gender.

Female

The first individual is a female, as indicated by her terminal appendages. Female dragonflies have a pair of cerci (superior appendages) that have little or no function.

A Black-shouldered Spinyleg dragonfly (Dromogomphus spinosus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female.

08 AUG 2016 | Riverbend Park | Black-shouldered Spinyleg (female)

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

The preceding dorsal view of the dragonfly shows its hind wings are rounded near the body, a good field marker for female clubtail dragonflies. In contrast, the hind wings of male clubtails are “indented.” Also notice the female “club” is slightly smaller than the male club, as shown in the following photos.

A Black-shouldered Spinyleg dragonfly (Dromogomphus spinosus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female.

08 AUG 2016 | Riverbend Park | Black-shouldered Spinyleg (female)

A Black-shouldered Spinyleg dragonfly (Dromogomphus spinosus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female.

08 AUG 2016 | Riverbend Park | Black-shouldered Spinyleg (female)

A Black-shouldered Spinyleg dragonfly (Dromogomphus spinosus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female.

08 AUG 2016 | Riverbend Park | Black-shouldered Spinyleg (female)

Male

Male dragonflies have three terminal appendages, collectively called “claspers,” that are used to grab and hold female dragonflies during mating: an upper pair of cerci (“superior appendages”); and a lower unpaired epiproct (“inferior appendage”).

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

Although the preceding photo seems to show four terminal appendages, do not be misled! The epiproct for Black-shouldered Spinyleg is essentially a wide plate with two prongs.

Notice the male’s middle leg (on the right side, facing forward) is shorter than either its front- or hind leg. I’m not sure whether the middle leg is malformed, or the result of an injury. Whatever the cause, it might explain why the dragonfly was especially skittish.

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

  • Genus Dromogomphus | Dromogomphus spinosus | Black-shouldered Spinyleg | male | top view
  • Genus Dromogomphus | Dromogomphus spinosus | Black-shouldered Spinyleg | male | side view

Copyright © 2016 Walter Sanford. All rights reserved.

Eastern Ringtail dragonfly (female)

August 15, 2016

An Eastern Ringtail dragonfly (Erpetogomphus designatus) was spotted during a photowalk along the Potomac River at Riverbend Park. This individual is a female, as indicated by her terminal appendages and the shape of its hind wings.

An Eastern Ringtail dragonfly (Erpetogomphus designatus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female.

04 AUG 2016 | Riverbend Park | Eastern Ringtail (female)

The following dorsal view of the same dragonfly shows its hind wings are rounded near the body, a good field marker for female clubtail dragonflies.

An Eastern Ringtail dragonfly (Erpetogomphus designatus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female.

04 AUG 2016 | Riverbend Park | Eastern Ringtail (female)

Copyright © 2016 Walter Sanford. All rights reserved.

Eastern Ringtail dragonflies (males)

August 13, 2016

Eastern Ringtail dragonfly (Erpetogomphus designatus) is a new species on my life list of odonates.

The following photos show the first one that I spotted during a photowalk along the Potomac River at Riverbend Park. This individual is a male, as indicated by his terminal appendages.

An Eastern Ringtail dragonfly (Erpetogomphus designatus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

04 AUG 2016 | Riverbend Park | Eastern Ringtail (male)

Like all male clubtail dragonflies, its hind wings are “indented” near the body; this distinctive field marker isn’t shown well by any of the photos in this gallery.

An Eastern Ringtail dragonfly (Erpetogomphus designatus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

04 AUG 2016 | Riverbend Park | Eastern Ringtail (male)

Another male was spotted near the same location, one of several Eastern Ringtails seen perching either on or near the boat ramp at the park.

An Eastern Ringtail dragonfly (Erpetogomphus designatus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male, perching in the obelisk position.

04 AUG 2016 | Riverbend Park | Eastern Ringtail (male)

I love a good head-tilt, or two!

An Eastern Ringtail dragonfly (Erpetogomphus designatus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

04 AUG 2016 | Riverbend Park | Eastern Ringtail (male)

The last photo shows a male Eastern Ringtail perching on a grassy area alongside the boat ramp.

An Eastern Ringtail dragonfly (Erpetogomphus designatus) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

04 AUG 2016 | Riverbend Park | Eastern Ringtail (male)

Copyright © 2016 Walter Sanford. All rights reserved.

Black-shouldered Spinyleg (male)

August 11, 2016

Black-shouldered Spinyleg dragonfly (Dromogomphus spinosus) is a new species on my life list of odonates. This is the first one that I spotted during a photowalk along the Potomac River at Riverbend Park.

This individual is a male, as indicated by its terminal appendages and the shape of its hind wings.

Bright yellow juveniles turn pale olive with age. Source Credit: Black-Shouldered Spinyleg, Dragonflies of Northern Virginia, by Kevin Munroe.

Contrast the size of the “club” at the tip of male’s abdomen with the female club, shown in my last photoblog post. Notice the male club is slightly larger than the female club.

The following dorsal view of the dragonfly shows its hind wings are “indented” near the body, a good field marker for male clubtail dragonflies. In contrast, the hind wings of female clubtails are rounded.

Black-shouldered Spinyleg is the only clubtail with broad, pale green thoracic stripes. Also notice the broad dark stripe on the “shoulder” of the thorax, hence the common name “Black-shouldered.” Although all dragonflies have spiny legs, Black-shouldered Spinyleg has large leg spines, especially on their hind legs.

Copyright © 2016 Walter Sanford. All rights reserved.


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