Archive for April, 2015

First Painted Skimmer of 2015

April 29, 2015
Painted Skimmer dragonfly (male)

24 APR 2015 | Huntley Meadows Park | Painted Skimmer (male)

The preceding photo shows the first Painted Skimmer dragonfly (Libellula semifasciata) spotted during Spring 2015, and the only one I saw all day. This individual is a male, as indicated by its terminal appendages. Four snaps and he was gone!

Some odonate experts think Painted Skimmer may be one of several migratory species of dragonflies. If this guy is on the vanguard of an approaching wave of migratory Painted Skimmers, then he must be WAY AHEAD of the group — I revisited Huntley Meadows Park again on 27 April 2015 and didn’t see a single Painted Skimmer.

Related Resources:

Editor’s Note: I spotted another male Painted Skimmer at Huntley Meadows Park on 28 April 2015. Can you say “follow-up post?”

Copyright © 2015 Walter Sanford. All rights reserved.

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Common Baskettail dragonfly

April 28, 2015

Another view of the same Common Baskettail dragonfly, as seen from a slightly different viewpoint. Good photo, Mike!

Mike Powell

Despite its name, the Common Baskettail dragonfly (Epitheca cynosura), one of the first dragonflies of the spring, has been observed only infrequently at my local marshland park. Therefore I was pretty excited when sharp-eyed fellow blogger and photographer Walter Sanford spotted a Common Baskettail last week when we were out together searching for dragonflies.

Walter consulted with some experts and  was able to confirm his initial identification of this dragonfly as a female. How do you tell the gender of a dragonfly? Check out Walter’s recent posting What was your first clue? to learn how he did it.

If you are more interested in photography than in dragonfly anatomy, check out Walter’s initial posting on the Common Baskettail dragonfly. We both photographed the dragonfly at the same time, but our angles of view and equipment were different, so the resulting images are similar, but not identical.

Personally i enjoy seeing how the creative choices that…

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What was your first clue?

April 27, 2015

I have photographed relatively few members of the Emerald Family of dragonflies. After tentatively identifying the following individual as a female Common Baskettail (Epitheca cynosura), I consulted the experts of the Northeast Odonata Facebook group for verification: I was fairly certain of the species; less certain of the gender.

Experienced odonate hunters like Chris Hill and Ed Lam looked at the specimen and quickly recognized its gender, as indicated by the cerci (terminal appendages) and thickness of its abdomen. In contrast, I haven’t seen enough baskettails to feel comfortable using those field markers to identify the gender.

So you may be wondering, “What was your first clue this individual is a female?” In a word (well, two) its subgenital plate, as shown in the following annotated image.

A Common Baskettail dragonfly (Epitheca cynosura) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

24 APR 2015 | Huntley Meadows Park | Common Baskettail (female)

A better view of the subgenital plate is provided by the following digital scan of the underside of the abdomen of a female Common Baskettail. The subgenital plate looks a little like a pair of calipers. Also known as vulvar lamina, the subgenital plate is located under the ninth abdominal segment (S9) of some female odonates and “serves to hold eggs in place during exophytic oviposition.” Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.

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Image used with permission from Ed Lam.

Related Resource: Common Baskettail dragonfly (male) – a tutorial illustrating male reproductive anatomy.

Editor’s Note: Special thanks to Chris Hill and Ed Lam, members of the Northeast Odonata Facebook group, for kindly confirming my tentative identification of the gender of this specimen and for teaching me about the subgenital plate (a.k.a., vulvar lamina) — a feature that I misidentified as an “ovipositor” in my initial post to the group.

Copyright © 2015 Walter Sanford. All rights reserved.

Common Baskettail dragonfly (female)

April 25, 2015

Common Baskettail dragonflies (Epitheca cynosura) are relatively uncommon at Huntley Meadows Park. I spotted this one during a long photowalk with Mike Powell to several remote locations in the forest.

Common Baskettail dragonfly (female)

24 APR 2015 | Huntley Meadows Park | Common Baskettail (female)

This individual is a female as indicated by its “simple cerci (appendages) and wide body.” Source Credit: Chris Hill, Northeast Odonata Facebook group.

Common Baskettail dragonfly (female)

24 APR 2015 | Huntley Meadows Park | Common Baskettail (female)

Common Baskettail is a member of the Emerald Family of dragonflies.

Copyright © 2015 Walter Sanford. All rights reserved.

Black and Yellow Argiope spider

April 23, 2015

The following photographs show a short time-series of the same Black and Yellow Argiope spider (Argiope aurantia) spotted during photowalks along the boardwalk at Huntley Meadows Park on two days in September 2014.

Look closely at both photos. Notice the spider has “mummified” its prey. Experts say spiders wrap their prey in silk in order to store food for later consumption.

Black and Yellow Argiope spider (Argiope aurantia)

17 September 2014

Each photo shows the spider with a freshly-wrapped “snack pack.”

Black and Yellow Argiope spider (Argiope aurantia)

19 September 2014

Copyright © 2015 Walter Sanford. All rights reserved.

New discoveries in 2014-2015

April 21, 2015

My interest in odonates, that is, dragonflies and damselflies, began during Summer 2011 at Huntley Meadows Park. Toward the end of Summer 2012 and continuing in 2013, my goal was to explore new venues for hunting odonates. Along the way, I spotted several species of odonates that are either uncommon or unknown to occur at Huntley Meadows, including Blue Corporal dragonfly, Stream Cruiser dragonfly, and Rambur’s Forktail damselfly, to name a few.

During 2014, continuing in 2015, I have been a man on a mission to explore the relatively unexplored areas at Huntley Meadows Park in search of habitat-specific odonates unlikely to be found in the central wetland area of the park. In retrospect, 2014-2015 has been a good run: five new species of odonates were discovered and added to the list of Dragonflies and Damselflies of Huntley Meadows Park.

Common Sanddragon dragonfly

Common Sanddragon dragonfly (Progomphus obscurus)

20 June 2014

Mike Powell and I collaborated to identify a clubtail dragonfly that Mike spotted on 17 June 2014. As it turns out, Mike had discovered a Common Sanddragon (Progomphus obscurus), a new species of dragonfly for Huntley Meadows Park. Mike guided me to the same spot on 20 June, where we photographed several sanddragons (like the male shown above), including two mating pairs!

Arrowhead Spiketail dragonfly

Arrowhead Spiketail dragonfly (male)

07 July 2014

I feel fortunate to have discovered an Arrowhead Spiketail dragonfly (Cordulegaster obliqua) — many experienced odonate hunters go years without seeing one of these handsome dragonflies!

Great Spreadwing damselfly

Great Spreadwing damselfly (male)

09 October 2014

Although I may not be the first ode-hunter to spot a Great Spreadwing damselfly (Archilestes grandis) at Huntley Meadows Park, I am the first person to notify the park manager of its occurrence. As a result, Great Spreadwing was added to the Friends of Huntley Meadows Park Odonata species list.

Southern Spreadwing damselfly/Sweetflag Spreadwing damselfly

Southern/Sweetflag Spreadwing damselfly (male)

23 May 2014

Time will tell which new species of spreadwing damselfly I discovered at Huntley Meadows Park. Either way, both Southern Spreadwing damselfly (Lestes australis) and Sweetflag Spreadwing damselfly (Lestes forcipatus) were formerly unknown to occur at the park.

Springtime Darner dragonfly

Springtime Darner dragonfly (female)

18 April 2015 | Photograph used with permission from Michael Powell.

Mike Powell and I co-discovered the first Springtime Darner (Basiaeschna janata) ever seen/photographed at Huntley Meadows Park! This individual is a female, as indicated by its coloration and terminal appendages.

Related Resources:

Copyright © 2015 Walter Sanford. All rights reserved.

Teamwork, and some take-aways

April 19, 2015

Mike Powell and I spent two consecutive Saturdays in April searching for a species of dragonfly that Kevin Munroe, Manager, Huntley Meadows Park, was reasonably certain should be at the park, although nobody had ever seen one. Turns out Kevin was right!

As we were walking through a remote part of the park, Mike spooked a winged insect as he walked past it: Mike didn’t see it; luckily I did. (Sometimes it’s good to be the tractor; sometimes it’s better to be the trailer.) At first I thought it might be another one of many crane flies we’d seen during our long walk, but as I moved closer to the insect’s new perch I realized we’d spotted our first “home-grown” dragonfly of the year! Like a dope, I didn’t bring a camera with me (more about that later) so I directed Mike to the place where the dragonfly was perching vertically a couple of feet above the ground. Mike was able to get a few shots at that spot, and a few more at its next perch. We lost sight of the dragonfly the last time it was spooked.

When we looked at one of the better photos on the LCD of Mike’s camera, the dragonfly looked a little like a Stream Cruiser dragonfly (Didymops transversa) on the small screen display. I asked Mike to scroll down so we could see a magnified view of the dragonfly’s terminal appendages. One look and I knew we’d found our quarry: the first Springtime Darner (Basiaeschna janata) ever seen/photographed at Huntley Meadows Park! This individual is a female, as indicated by its coloration and terminal appendages (see “Related Resources, below).

Springtime Darner dragonfly (female)

18 April 2015 | Photograph used with permission from Michael Powell.

So what are the take-aways I mentioned in the title of this post?

  • Always carry a camera when you go into the field. I decided to travel light for a long, difficult walk on a hot and humid day: good thought; bad idea!
  • Set a goal or goals for your photowalks and do your homework so you know what the subject looks like and what its habits are. One important field marker: Springtime Darners are smaller than other members of the Darner Family; they appear to be the same size as an average-size member of the Skimmer Family.
  • Teamwork works! Mike is very familiar with the places we walked; I am familiar with the dragonfly for which we were searching. Working together, Mike and I achieved our goal and co-discovered another new species of odonate at Huntley Meadows Park.

Related Resources:

Copyright © 2015 Walter Sanford. All rights reserved.

Autumn Meadowhawk dragonfly terminal appendages

April 17, 2015

Autumn Meadowhawk (Sympetrum vicinum) is a member of the Skimmer Family of dragonflies that is commonly spotted during the fall months at many water bodies in the mid-Atlantic United States.

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”).

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30 SEP2014 | Huntley Meadows Park | Autumn Meadowhawk (male)

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

Autumn Meadowhawk dragonfly (female)

11 NOV 2014 | Huntley Meadows Park | Autumn Meadowhawk (female)

Related Resources: Odonate Terminal Appendages.

Copyright © 2015 Walter Sanford. All rights reserved.

Blue Dasher dragonfly terminal appendages

April 15, 2015

Blue Dasher (Pachydiplax longipennis) is a member of the Skimmer Family of dragonflies that is commonly spotted during the summer months at many water bodies in the mid-Atlantic United States.

Blue Dashers display sexual dimorphism; terminal appendages may be used to differentiate immature males from females.

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

Related Resources: Odonate Terminal Appendages.

Copyright © 2015 Walter Sanford. All rights reserved.

Blue Dasher dragonflies (mating pair)

April 13, 2015

A mating pair of Blue Dasher dragonflies (Pachydiplax longipennis) was spotted along the boardwalk in the central wetland area hemi-marsh at Huntley Meadows Park on 10 September 2014.

The pair is shown “in wheel.” All odonates (dragonflies and damselflies) have a 10-segmented abdomen, numbered from front to back: male dragonfly secondary genitalia are located in segments two and three (2 and 3); female genitalia in segment eight (8). Therefore, the male dragonfly is on top; the female is on the bottom.

Blue Dasher dragonflies (mating pair, in wheel)

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”).

Blue Dasher dragonflies (mating pair, in wheel)

Copyright © 2015 Walter Sanford. All rights reserved.


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