Archive for August, 2016
August 31, 2016
Most experienced odonate hunters would never mistake an orangish-red mature male Halloween Pennant dragonfly (Celithemis eponina) for a yellow mature female of the same species, right? Maybe, maybe not. Color is quite variable, depending upon gender, age, and natural variation. Usually it’s better to use terminal appendages to identify gender rather than color.
Female
The following Halloween Pennant was spotted at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This 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.
(See a full-size version of the original photo, without annotation.)
Immature male
The next Halloween Pennant dragonfly was spotted at Meadowood Recreation Area, Fairfax County, Virginia USA. This individual is an immature male, as indicated by his yellowish coloration and terminal appendages.
(See a full-size version of the original photo, without annotation.)
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”).
Female (displaying unusual coloration)
The last Halloween Pennant was spotted near the Pollinator Garden at Meadowood Recreation Area. This individual is a female, as indicated by her terminal appendages. Notice this specimen has orangish-red coloration similar to a mature male of the same species, including magenta pterostigmata.
Related Resources: Digital Dragonflies, presenting high-resolution digital scans of living dragonflies.
- Genus Celithemis | Celithemis eponina | Halloween Pennant | female | top view
- Genus Celithemis | Celithemis eponina | Halloween Pennant | female | side view
- Genus Celithemis | Celithemis eponina | Halloween Pennant | male | top view
- Genus Celithemis | Celithemis eponina | Halloween Pennant | male | side view
Copyright © 2016 Walter Sanford. All rights reserved.
Tags:Celithemis eponina, cerci, claspers, epiproct, female, Halloween Pennant dragonfly, immature male, Meadowood Recreation Area, Occoquan Bay National Wildlife Refuge, pterostigma, Skimmer Family, terminal appendages, wildlife photography
Posted in Aperture, Canon 580EX Speedlite, digital photography, dragonflies, education, natural science, Panasonic DMC-FZ150, Photoshop | Leave a Comment »
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.
Tags:Clubtail Family, Cobra Clubtail dragonfly, female, Gomphus vastus, male, Potomac River, predator, prey, Riverbend Park, terminal appendages, wildlife photography
Posted in Aperture, butterflies and moths, Canon 580EX Speedlite, damselflies, digital photography, dragonflies, natural science, Panasonic DMC-FZ150 | Leave a Comment »
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.
Tags:Clubtail Family, Eastern Ringtail dragonfly, Erpetogomphus designatus, female, male, Potomac River, predator, prey, Riverbend Park, terminal appendages, wildlife photography
Posted in Aperture, Canon 580EX Speedlite, digital photography, dragonflies, natural science, Panasonic DMC-FZ150, photowalking | Leave a Comment »
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.
Both males were photographed at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge (OBNWR), Prince William County, Virginia USA.
Copyright © 2016 Walter Sanford. All rights reserved.
Tags:Calico Pennant dragonfly, Celithemis elisa, male, Occoquan Bay National Wildlife Refuge, Odonart, Painted Turtle Pond, Skimmer Family
Posted in Aperture, Canon 580EX Speedlite, digital photography, dragonflies, natural science, Panasonic DMC-FZ150 | 1 Comment »
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.
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.
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.
More males
Many more male Powdered Dancer damselflies were spotted during a follow-up photowalk on 08 August 2016.
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 Argia (Dancers) fits into the bigger picture of the Order Odonata, Suborder 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.
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).
- Argia (e.g., Blue-fronted Dancer, Blue-tipped Dancer, Variable Dancer)
- Enallagma (e.g., Big Bluet, Familiar Bluet, Orange Bluet, Stream Bluet)
- Ischnura (e.g., Eastern Forktail, Fragile Forktail, Rambur’s Forktail)
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.
Tags:Argia moesta, Dancers (Argia), Family Coenagrionidae, female, male, polymorphic, Potomac River, Powdered Dancer damslelfly, Riverbend Park, terminal appendages, wildlife photography
Posted in Aperture, Canon 580EX Speedlite, damselflies, digital photography, natural science, Panasonic DMC-FZ150, photowalking | 1 Comment »
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.
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.
(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! No problem. See the digital scans under “Related Resources.”
(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”).
Related Resources:
Copyright © 2016 Walter Sanford. All rights reserved.
Tags:American Rubyspot damselfly, Broad-winged Damselflies, cerci, claspers, Family Calopterygidae, female, Hetaerina americana, male, paraprocts, Potomac River, Riverbend Park, styli, terminal appendages
Posted in Aperture, Canon 580EX Speedlite, damselflies, digital photography, education, natural science, Panasonic DMC-FZ150, Photoshop | 6 Comments »
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.
(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).
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”).
(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.
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.
Tags:cerci, claspers, Clubtail Family, Eastern Ringtail dragonfly, epiproct, Erpetogomphus designatus, Potomac River, Riverbend Park, terminal appendages, wildlife photography
Posted in Aperture, Canon 580EX Speedlite, digital photography, dragonflies, education, natural science, Panasonic DMC-FZ150, Photoshop, photowalking | 8 Comments »
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.
(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
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.
Tags:Black-shouldered Spinyleg dragonfly, cerci, claspers, Clubtail Family, Dromogomphus spinosus, epiproct, female, male, malformed, Potomac River, Riverbend Park, terminal appendages, wildlife photography
Posted in Aperture, Canon 580EX Speedlite, digital photography, dragonflies, education, natural science, Panasonic DMC-FZ150, Photoshop, photowalking | 11 Comments »
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.
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.
Copyright © 2016 Walter Sanford. All rights reserved.
Tags:Clubtail Family, Eastern Ringtail dragonfly, Erpetogomphus designatus, female, Potomac River, Riverbend Park, terminal appendages, wildlife photography
Posted in Aperture, Canon 580EX Speedlite, digital photography, dragonflies, natural science, Panasonic DMC-FZ150, photowalking | 2 Comments »
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.
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.
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.
I love a good head-tilt, or two!
The last photo shows a male Eastern Ringtail perching on a grassy area alongside the boat ramp.
Copyright © 2016 Walter Sanford. All rights reserved.
Tags:Clubtail Family, Eastern Ringtail dragonfly, Erpetogomphus designatus, head-tilt, male, Potomac River, Riverbend Park, terminal appendages, wildlife photography
Posted in Aperture, Canon 580EX Speedlite, digital photography, dragonflies, natural science, Panasonic DMC-FZ150, photowalking | 1 Comment »
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