Uncommonly cooperative Common Baskettail

A Common Baskettail (Epitheca cynosura) was spotted on 24 May 2016 during a photowalk around Mulligan Pond at Jackson Miles Abbott Wetland Refuge.

This individual is a male, as indicated by its terminal appendages.

Some segments of the lake shoreline were patrolled by a single male Common Baskettail dragonfly, like the one featured in this photo set. Common Baskettails are fliers rather than perchers. I noticed this individual would fly back-and-forth for 10s of minutes, then pause to perch for a while — never longer than a minute-or-so.

I staked out a position near the center of the male’s patrol route and waited for him to land. Although he never landed in the same spot, all of the perches were confined to a relatively small area.

My front-row seat had an obstructed view for the last shot. Soon afterward, the dragonfly simply disappeared. But hey, it was a good show while it lasted!

Copyright © 2016 Walter Sanford. All rights reserved.

Cobra Clubtail head-tilts

Regular readers of my photoblog know I’m fond of head-tilts in which the dragonfly seems to display some of its personality, especially when the individual is looking at me. Like the following female Cobra Clubtail dragonfly (Gomphus vastus), who I imagine is thinking “Take a picture. It will last longer.”

16 MAY 2016 | Riverbend Park | Cobra Clubtail (female)

In the next photo, another female has turned her head nearly upside-down. OK, that’s just crazy looking! It reminds me of the movie The Exorcist (1973).

16 MAY 2016 | Riverbend Park | Cobra Clubtail (female)

The male in the last photo is probably thinking “Hey buddy, enough with the bright flashes of light!”

16 MAY 2016 | Riverbend Park | Cobra Clubtail (male)

Copyright © 2016 Walter Sanford. All rights reserved.

Southern- or Sweetflag Spreadwing?

I spotted a skittish spreadwing damselfly on 14 May 2016 during a photowalk around Enchanted Pond, Meadowood Recreation Area. I was able to shoot some photos of the spreadwing during a follow-up visit on 20 May 2016.

This individual is a member of the Family Lestidae of damselflies (Spreadwings): it is either a Southern Spreadwing damselfly (Lestes australis) or Sweetflag Spreadwing damselfly (Lestes forcipatus). It is a male, as indicated by its terminal appendages: Southern Spreadwing; Sweetflag Spreadwing.

According to Ed Lam, author and illustrator of Damselflies of the Northeast, “Male Southern and Sweetflag cannot be separated in the field.”

In my experience at Huntley Meadows Park, Southern Spreadwing is an early season (spring) species; Sweetflag Spreadwing is a late season (fall) species. In deference to Ed Lam’s expertise, I’ll go with the either/or classification rather than a somewhat speculative single species identification.

Copyright © 2016 Walter Sanford. All rights reserved.

Phenology

Phenology (noun) is defined as “the study of cyclic and seasonal natural phenomena, especially in relation to climate and plant and animal life.”

There is an annual cycle of odonate activity that can be subdivided into three broad categories: Early Season (spring); Mid-season (summer); and Late Season (fall).

It appears the time has passed for many of the early season species of dragonflies, such as Blue Corporal (Ladona deplanta). I spotted one Blue Corporal during a photowalk on 14 May 2016 at Hidden Pond, Meadowood Recreation Area; no Blue Corporals were seen during a follow-up visit on 20 May 2016.

This individual is a female, as indicated by her terminal appendages.

I prefer to photograph dragonflies on simple, uncluttered backgrounds such as the piece of heavy lumber shown above. In my opinion, it is easier to see key field marks when the background isn’t a distraction.

In contrast, Michael Powell — a good friend and photowalking buddy — prefers photos of dragonflies in more natural settings. Here’s to you, Mike!

Related Resources:

• Dragonflies of Northern Virginia – Flight Periods
• Dragonflies & Damselflies of Loudoun County – Checklist
• National Phenology Network

Copyright © 2016 Walter Sanford. All rights reserved.

Happy World Turtle Day!

The purpose of World Turtle Day, May 23, sponsored yearly since 2000 by American Tortoise Rescue, is to bring attention to, and increase knowledge of and respect for, turtles and tortoises, and encourage human action to help them survive and thrive. Source Credit: World Turtle Day, Wikipedia.

An Eastern Box Turtle (Terrapene carolina carolina) was spotted on 14 May 2016 at West Meadows Trails, Meadowood Recreation Area, Fairfax County, Virginia USA.

A turtle is a good metaphor for the wisdom of slowing the rapid pace of day-to-day existence in order to enjoy some of life’s simpler pleasures.

I visited this location hoping to find several species of uncommon odonates, but I wasn’t so driven that I couldn’t take a few minutes to photograph an animal that I see less frequently than one might expect.

Copyright © 2016 Walter Sanford. All rights reserved.

Cobra Clubtail dragonflies (females)

For those species of dragonflies that do not display sexual dimorphism, males and females are nearly identical in appearance except for their terminal appendages. For example, male and female Cobra Clubtail dragonflies (Gomphurus vastus) are similar in appearance.

Two field marks can be used to identify female Cobra Clubtails, as shown in the following annotated images: 1) they have two terminal appendages (cerci) rather than three (males); and 2) their hind wings are rounded rather than “indented” (males).

16 MAY 2016 | Riverbend Park | Cobra Clubtail (female)

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

All female dragonflies have a pair of cerci (superior appendages) that have little or no function.

16 MAY 2016 | Riverbend Park | Cobra Clubtail (female)

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

Related Resource: Cobra Clubtail claspers [males], by Walter Sanford.

Copyright © 2016 Walter Sanford. All rights reserved.

Cobra Clubtail claspers

All 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”).

A Cobra Clubtail dragonfly (Gomphurus vastus) was spotted at Riverbend Park, Fairfax County, Virginia USA. Two field marks indicate this individual is a male, as shown in the following annotated image: 1) it has three terminal appendages; and 2) its hind wings are slightly “indented.”

16 MAY 2016 | Riverbend Park | Cobra Clubtail (male)

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

All male dragonflies have three terminal appendages, right? Look closely at the preceding annotated image. Notice there are four “prongs” at the posterior end of the abdomen. Cobra Clubtails feature a two-pronged epiproct. Just thought I should clarify any cognitive dissonance that may have been caused by looking at these images!

16 MAY 2016 | Riverbend Park | Cobra Clubtail (male)

Notice the male’s abdomen is slightly more elevated in the preceding photo than in the annotated image.

Males perch on shore, or on rocks in rocky rivers, with abdomen elevated, then fly beats up and down. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 5952-5953). Princeton University Press. Kindle Edition.

Some species of dragonflies 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. Given the orientation of Cobra Clubtail relative to the Sun, I’m guessing this type of perching behavior is probably intended to mark territory and attract mates.

Editor’s Note: Female Cobra Clubtail dragonfly terminal appendages will be featured in a follow-up post: Cobra Clubtail dragonflies (females).

Copyright © 2016 Walter Sanford. All rights reserved.

Common Baskettail dragonfly (male, in flight)

A Common Baskettail (Epitheca cynosura) was spotted on 14 May 2016 at Enchanted Pond, Meadowood Recreation Area, Fairfax County, Virginia USA. This individual is a male, as indicated by its terminal appendages. Notice the male’s bright blue-green eyes in the preceding photo. It’s easy to see why Common Baskettail is a member of the Emerald Family of dragonflies!

Enchanted Pond is relatively small. The shoreline seemed to be subdivided into imaginary segments of valuable real estate; each segment was patrolled by a single male Common Baskettail dragonfly. There were frequent aerial skirmishes when one male strayed into the territory of another. During nearly an hour of observation, I never saw one of the males land. Talk about stamina!

Copyright © 2016 Walter Sanford. All rights reserved.

Aeshnidae exuvia

An odonate exuvia was spotted on 14 August 2012 along the boardwalk in the central wetland area at Huntley Meadows Park. The specimen was broken into three pieces when I found it: head and thorax; wing pads; and abdomen.

This individual is a member of the Family Aeshnidae (Darners). Here’s the decision tree I used to tentatively identify the exuvia as a member of the Darner Family.

• The specimen has a flat labium that doesn’t cover the face (not mask-like).
• Antennae are thin and thread-like (not club-like, as in Gomphidae).

Photo Set 1

Notice the labium is flat and isn’t mask-like, that is, doesn’t cover the face of the larva/exuvia.

Head and thorax (lateral view).

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

Also notice the antennae are thin and thread-like, as shown in the following annotated image.

Head and thorax (dorsal side).

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

The shape of the mentum and prementum (especially the rounded palpal blades) indicates this specimen is a Common Green Darner dragonfly (Anax junius), one of the more common species of Aeshnidae found at Huntley Meadows Park.

Head and thorax (ventral side).

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

Photo Set 2

The next photo shows the wing pads as well as part of abdominal segment one (S1). All odonates have a 10-segmented abdomen. The anterior side is toward the bottom of the photo; posterior toward the top.

Wing pads (dorsal view).

Abdominal segments two through 10 (S2-10) are shown in the following photo.

Abdomen (dorsal view).

Lateral spines along abdominal segments seven, eight, and nine (S7-9) verifies the genus and species as Anax junius. Notice the faint feature on segment nine (S9), highlighted by a white circle. This is a “rudimentary ovipositor,” according to SueandJohn KestrelHaven, active members of the “Northeast Odonata” Facebook group. An ovipositor is used for egg-laying by all adult damselflies and some species of adult dragonflies: females have this feature; males do not.

Abdomen (ventral view).

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

Related Resources

• Vimeo video: Identifying dragonfly larva to family (8:06)
• Anatomy of a Dragonfly Larva, annotated illustration courtesy Jay Smith
• Identification Keys to Northeastern Anisoptera Larvae, compiled by Ken Soltesz.
• Odonate Exuviae, by Walter Sanford

Tech Tips

The following equipment was used to shoot the preceding photographs:

• Photo Set 1: Canon EOS 5D Mark II digital camera; 50mm lens (“Nifty Fifty”) plus Raynox DCR-250 close-up filter; Canon 580EX Speedlite (ETTL mode) off-camera, using a pair of Yongnuo YN622C II Wireless Flash Trigger Transceivers; and a Nissin i40 (off-camera, in SF mode).
• Photo Set 2: Fujifilm X-T1 digital camera; Fujinon XF18-55mm (27mm-82.5mm, 35mm equivalent) zoom lens plus “Fotasy” brand 10mm extension tube; Fujifilm Shoe Mount Flash EF-42 (on-camera, in TTL mode); Nissin i40 external flash unit (off-camera, in SD mode).

Adobe Photoshop CC 2015 was used to annotate selected images.

The following photo reveals a behind the scenes look at my low-tech solution for staging specimen parts: a plastic toothpick (tan) from a Swiss Army knife held by a small plastic clothespin (green); both parts were held by an alligator clip (silver) mounted on a short, flexible arm.

All specimens were staged in front of the same opaque white plastic background. Hard to believe, huh? I own an 18% gray scale card; at some point, I should start using it to adjust the white balance in my macro photos!

Related Resource: Odonate Exuviae – a hyperlinked list of identification guides to many species of odonate exuviae from seven families of dragonflies and three families of damselflies.

Copyright © 2016 Walter Sanford. All rights reserved.

Common Whitetail dragonfly (teneral female)

A Common Whitetail dragonfly (Plathemis lydia) was spotted on 15 April 2016 at Huntley Meadows Park. This individual is a teneral female, as indicated by its terminal appendages (cerci) and the pale coloration of her wings.

Miraculous metamorphosis, the last post in my photoblog, featured a three-hour time-series of still photos documenting the astounding transformation of a female Common Whitetail dragonfly from a larva to an adult. The teneral female dragonfly in this post emerged recently, probably sometime during the same day these photos were taken.

A pattern of dark spots on all four wings, characteristic of female Common Whitetail dragonflies, will develop within a few days to a week-or-so after emergence.

Copyright © 2016 Walter Sanford. All rights reserved.