Archive for November, 2016

New late-date for Blue-faced Meadowhawk

November 11, 2016
A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male.

06 NOV 2016 | 10:37 AM | HMP | Blue-faced Meadowhawk (male)

Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) was spotted near a vernal pool in Huntley Meadows Park (HMP). This individual is a male, as indicated by his coloration and terminal appendages.

A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male.

06 NOV 2016 | 10:58 AM | HMP | Blue-faced Meadowhawk (male)

Notice the 21-minute time difference between the two photos. I thought I’d spotted two males until I saw identical damage to the right hindwing (facing forward) when I was editing the photos.

27 October was my previous late-date for Blue-faced Meadowhawk, tied with the record late-date for the Commonwealth of Virginia. 06 November is both a new personal late-date as well as a record-setting late-date for the state.

Editor’s Note: If you check the EXIF for both photos, then you will see the time stamp is one hour later than the times shown above. 06 November was the first time I used my camera since the end of Daylight Saving Time (at 2:00 a.m. the same day) — I forgot to reset the time in-camera!

Copyright © 2016 Walter Sanford. All rights reserved.

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Great Spreadwing (female terminal appendages)

November 9, 2016

Fall 2016 hadn’t been good for finding Great Spreadwing damselflies (Archilestes grandis) at Huntley Meadows Park. A formerly fishless vernal pool in a remote location at the park was less than productive, yielding only two males as a result of intense searches during September and October. Given this context, imagine my surprise and delight when several Great Spreadwings were spotted on a mild day in early November, including my first sighting of a single female!

The following photo shows a male Great Spreadwing damselfly spotted on the same day and near the same location as the female. Notice its deep blue eyes, familiar yellow racing stripe on the side of its thorax, bluish-white coloration on abdominal segments 9-10 (S9-10), and distinctive terminal appendages (claspers).

Although female Great Spreadwings feature the same yellow thoracic stripe as males, several other field markers are different. Female eyes are paler blue and two-toned. Females have a noticeably thicker abdomen, minus the male coloration on S9-10. And of course, female terminal appendages are different from male appendages.

A Great Spreadwing damselfly (Archilestes grandis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

06 NOV 2016 | Huntley Meadows Park | Great Spreadwing (female)

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

Female Great Spreadwing damselflies, like all female odonates, have two cerci (sing. cercus), superior appendages that have little or no function. Also notice two styli (sing. stylus), structures that serve as sensors (like “curb feelers“) in egg positioning during oviposition.

A Great Spreadwing damselfly (Archilestes grandis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

06 NOV 2016 | Huntley Meadows Park | Great Spreadwing (female)

All three photos of the female are full-frame, that is, uncropped; the photo of the male was cropped slightly, only because I’m almost as obsessed with the way the edges of a photo look as the subject of the photo! Although I’m not opposed to cropping photos for better composition, I prefer to get it right in-camera.

A Great Spreadwing damselfly (Archilestes grandis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

06 NOV 2016 | Huntley Meadows Park | Great Spreadwing (female)

Related Resources:

Editor’s Note: If you check the EXIF for all four photos, then you will see the time stamp is one hour later than the times shown above. 06 November was the first time I used my camera since the end of Daylight Saving Time (at 2:00 a.m. the same day) — I forgot to reset the time in-camera!

Copyright © 2016 Walter Sanford. All rights reserved.

Now playing at a theater near you…

November 7, 2016

The first two adult Autumn Meadowhawk dragonflies (Sympetrum vicinum) of 2016 were spotted at Mason Neck West Park, Fairfax County, Virginia USA. Both individuals are males, as indicated by their coloration and terminal appendages.

Male 1

The first male was perching on aquatic vegetation growing in a small water retention pond at the park.

Male 2

The second male was spotted perching on grasses growing on a knoll overlooking the pond.

Related Resources: The first teneral Autumn Meadowhawks were observed beginning in mid-June 2016; see More previews of coming attractions for details. Every year, meadowhawk dragonflies — including Blue-faced Meadowhawks and Autumn Meadowhawks — mysteriously disappear for several months until they reappear sometime during fall.

Autumn Meadowhawks are one of the more common fall species of odonates. The species is well-adapted for survival in cooler temperatures and has been spotted as late as January 3rd in Northern Virginia!

Copyright © 2016 Walter Sanford. All rights reserved.

More previews of coming attractions

November 5, 2016

Several Autumn Meadowhawk dragonflies (Sympetrum vicinum) were spotted during photowalks at two wildlife watching parks located in Northern Virginia (suburban Washington, D.C.). All specimens are teneral, as indicated by their coloration and the tenuous appearance of their wings.

Occoquan Bay National Wildlife Refuge

During mid-June 2016, a single Autumn Meadowhawk was spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is a teneral female, as indicated by its terminal appendages.

Female abdomens are slightly thicker than those of males and noticeably flared toward both the thorax and tip of the abdomen. The “subgenital plate,” located under the ninth abdominal segment (S9), is a large scoop-like structure used for laying eggs (exophytic oviposition).

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is a teneral female.

18 JUN 2016 | OBNWR | Autumn Meadowhawk (teneral female)

The dragonfly is perching on “soft rush” (Juncus effusus), the common name for the shoreline/emergent plant with a light green round stem and brownish flowers shown in the preceding photo. Soft rush is common in wetland areas. Thanks to Christopher Wicker and Bonne Clark, naturalists at OBNWR, for identifying the plant.

Huntley Meadows Park

About one week later, many teneral Autumn Meadowhawks were spotted at a vernal pool in Huntley Meadows Park, Fairfax County, Virginia USA.

The first individual is a teneral female, perching on soft rush.

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral female.

24 JUN 2016 | HMP | Autumn Meadowhawk (teneral female)

The next specimen is also a teneral female.

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral female.

24 JUN 2016 | HMP | Autumn Meadowhawk (teneral female)

The following individual is a teneral male, as indicated by his terminal appendages.

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral male.

24 JUN 2016 | HMP | Autumn Meadowhawk (teneral male)

The last specimen is another teneral male.

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral male.

24 JUN 2016 | HMP | Autumn Meadowhawk (teneral male)

Editor’s Notes: This post is a belated companion piece for Previews of coming attractions, published on 04 June 2016, that documented teneral Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) observed during late-May 2016. About two weeks later, the first teneral Autumn Meadowhawks were observed.

Both Blue-faced Meadowhawks and Autumn Meadowhawks are classified as fall species of odonates. In the mid-Atlantic United States, meadowhawks seem to disappear for several months after they emerge during early summer and reappear during fall. Where do they go? No one knows for sure. I speculate Blue-faced Meadowhawks and Autumn Meadowhawks are arboreal species of dragonflies that return to the ground/water when it’s time to mate.

Related Resources:

Copyright © 2016 Walter Sanford. All rights reserved.

Russet-tipped Clubtail claspers

November 3, 2016

Another Russet-tipped Clubtail dragonfly (Stylurus plagiatus) was spotted during a photowalk at Mulligan PondJackson Miles Abbott Wetland Refuge (JMAWR).

This individual is a male, as indicated by the large russet-colored club at the end of his abdomen, “indented” hindwings (see annotated image, below), and his terminal appendages.

A Russet-tipped Clubtail dragonfly (Stylurus plagiatus) spotted at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This individual is a male.

14 OCT 2016 | JMAWR | Russet-tipped Clubtail (male)

I like the way the hint of red coloration in the fall foliage complements the male’s russet-colored club.

A Russet-tipped Clubtail dragonfly (Stylurus plagiatus) spotted at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This individual is a male. [*]

14 OCT 2016 | JMAWR | Russet-tipped Clubtail (male)

This guy was by far the most cooperative of several Russet-tipped Clubtails spotted at the same location, as evidenced by the fact that he allowed me to shoot 119 photos in a variety of poses. Several of the better photos in the set were cherry-picked for this post; more photos may be published in a follow-up post.

A Russet-tipped Clubtail dragonfly (Stylurus plagiatus) spotted at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This individual is a male. [*]

14 OCT 2016 | JMAWR | Russet-tipped Clubtail (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”).

A Russet-tipped Clubtail dragonfly (Stylurus plagiatus) spotted at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This individual is a male.

14 OCT 2016 | JMAWR | Russet-tipped Clubtail (male)

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

Notice the epiproct is a large “plate” that spans both cerci, as shown in the full-size version of the preceding photo.

Male Russet-tipped Clubtails have a larger, more colorful club than females of the same species, and their terminal appendages are shaped differently. Compare and contrast the appearance of males and females by looking at the following “Related Resources.”

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

  • Genus Stylurus | Stylurus plagiatus | Russet-tipped Clubtail | male | top view
  • Genus Stylurus | Stylurus plagiatus | Russet-tipped Clubtail | female | top view
  • Genus Stylurus | Stylurus plagiatus | Russet-tipped Clubtail | female | side view

Copyright © 2016 Walter Sanford. All rights reserved.

What’s my gender?

November 1, 2016

The following Common Green Darner dragonfly (Anax junius) was spotted near a vernal pool in a remote location at Huntley Meadows Park.

Can you identify its gender? You may want to refer to Sexing Common Green Darner dragonflies, my last blog post, before choosing an answer.

Whatever its gender, this individual is what I call a “freshie,” that is, an odonate that emerged recently but may not fit the strict definition of “teneral.” You could call the dragonfly either “post-teneral” or “immature” but it’s definitely not mature, as indicated by the light tan eye color.

Editor’s Note: The dark stripe extending into S2 is the most obvious field marker indicating this dragonfly is female.

Copyright © 2016 Walter Sanford. All rights reserved.


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