Posts Tagged ‘emergence’

Miraculous metamorphosis

February 22, 2018

It’s hard to believe an odonate larva that looked like this…

…transformed into the adult dragonfly shown below.

Image used with permission from Bob Perkins.

The Backstory

Bob Perkins, a good friend and fellow Virginian, has been collecting and rearing odonate larvae since 01 January 2017. Bob’s success rate is extraordinarily high, meaning most of the larvae he collects live to emerge as adults.

Bob collected an unknown species of clubtail larva in February 2017 from a stream located in either Carroll- or Grayson County, Virginia USA. The larva emerged from one of Bob’s holding tanks on 13 March 2017 and metamorphosed into an adult female Sable Clubtail dragonfly (Stenogomphurus rogersi).

Amateur- and professional scientists collect and rear odonate larvae in order to see what adult species emerge. Then it is possible to reverse-engineer the morphological characters that enable identification of specific species of larvae. An upcoming blog post will feature information about how to identify Sable Clubtail larvae.

Tech Tips

The first image is a composite of nine (9) photos taken using the following equipment: Canon EOS 5D Mark II digital camera, in manual mode; Canon MP-E 65mm Macro lens (manual focus only, set for 3x magnification); and Canon MT-26EX-RT Macro Twin Lite.

Adobe Photoshop CC 2017 was used to focus stack the photos and post-process the final output.

The second image was taken by Bob Perkins, soon after emergence, using a Canon EOS Rebel T3i camera body and Canon EF-S 60mm macro lens.

Copyright © 2018 Walter Sanford. All rights reserved.

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New discoveries in 2017 (odonates)

December 28, 2017

There’s always more to discover/learn! My odonate-related new discoveries in 2017 are presented in reverse-chronological order.

Fine-lined Emerald dragonfly

A Fine-lined Emerald dragonfly (Somatochlora filosa) was spotted at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is one of several males spotted during a period of a week-or-so in mid-September 2017.

Immature male Calico Pennant

20 JUN 2017 | OBNWR | Calico Pennant (immature male)

A Calico Pennant dragonfly (Celithemis elisa) was spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is an immature male. Notice its coloration is similar to female Calico Pennants.

Allegheny River Cruiser dragonfly

An Allegheny River Cruiser (Macromia alleghaniensis) was netted by Mike Blust at Hardware River Wildlife Management Area, Fluvanna County, Virginia USA. This individual is a male.

Harpoon Clubtail dragonfly

09 JUN 2017 | Highland County, VA | Harpoon Clubtail (male)

A Harpoon Clubtail dragonfly (Phanogomphus descriptus) was spotted at “Straight Fork,” Highland County, Virginia USA. This individual is a male. Sincere thanks to fellow Virginians Karen Kearney and Mike Boatwright for guiding me to this unique high-elevation habitat.

It’s worth noting that I saw two more new species during the same trip: Riffle Snaketail (Ophiogomphus carolus); and Dot-tailed Whiteface (Leucorrhinia intacta).

Those who know me well are familiar with one of many “Walterisms”: “I haven’t ‘seen’ something until I have photographed it.” My rationale is two-fold: 1) A photograph verifies a sighting. 2) The detail visible in a good photograph exceeds the acuity of the human eye. Suffice it to say I saw two other species but haven’t seen them. Makes sense to me!

Swift River Cruiser dragonfly

A Swift River Cruiser dragonfly (Macromia illinoiensis) was spotted at Riverbend Park, Fairfax County, Virginia USA. This individual is an emergent/teneral female.

Spine-crowned Clubtail dragonfly

A Spine-crowned Clubtail dragonfly (Hylogomphus abbreviatus) spotted along Bull Run at Hemlock Overlook Regional Park, Fairfax County, Virginia USA. This individual is a male. A female was spotted on the same day at a nearby location.

Epitheca cynosura exuvia

A Common Baskettail dragonfly (Epitheca cynosura) exuvia was collected at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

Epitheca princeps exuvia

05 MAR 2017 | Prince Baskettail (Epitheca princeps) | exuvia (face-head)

A Prince Baskettail dragonfly (Epitheca princeps) exuvia was collected from an unknown location. This specimen was on temporary loan from Huntley Meadows Park, Fairfax County, Virginia USA.

Copyright © 2017 Walter Sanford. All rights reserved.

Exuviart

August 22, 2017

Regular readers of my blog remember when I coined the term “Odonart” and created an “Odonart Portfolio.”

I just coined a new term: “Exuviart.” Exuviart is a concatenation of two words: exuvia; and art. The following photographs are the first additions to the Exuviart wing of my Odonart Portfolio.


Unpublished Photo

An Eastern Amberwing dragonfly (Perithemis tenera) exuvia, from the Family Libellulidae (Skimmers), was collected from the Potomac River in Fairfax County, Virginia USA.

Whenever possible, I like to collect exuviae along with some of the vegetation that was the site for emergence. The vegetation helps to show scale. In this case, the small specimen is approximately 1.4 cm (~0.6″) in length and approximately 0.6 cm (~0.2″) in maximum width. I like the way the desiccated leaf retained its color and gained a velvety texture.

Tech Tips

The following equipment was used to shoot the preceding photograph: Canon EOS 5D Mark II DSLR; Canon EF100mm f/2.8 Macro lens plus Raynox DCR-250 close-up filter; Canon 580EX II Speedlite; Canon 580EX Speedlite; and a coiled six-foot Vello Off-Camera TTL Flash Cord for Canon Cameras. The specimen was staged on a piece of white plastic (12″ square, matte finish).


Published Photos

A Common Green Darner dragonfly (Anax junius) exuvia, from the Family Aeshnidae (Darners), was collected at Hidden Pond, Meadowood Recreation Area (MRA), Fairfax County, Virginia USA.

Tech Tips

The following equipment was used to shoot the preceding photograph: Canon EOS 5D Mark II digital camera, in manual mode; Canon EF100mm f/2.8L Macro lens (set for manual focus); Canon 580EX II external flash, off-camera, in manual mode; Canon 580EX external flash, off-camera, in manual mode; and a Yongnuo YN-622C-TX E-TTL II Wireless Flash Controller for Canon plus a two-pack of Yongnuo YN-622C II E-TTL Wireless Flash Transceivers for Canon.


A Cobra Clubtail dragonfly (Gomphurus vastus) exuvia, from the Family Gomphidae (Clubtails), was collected at Riverbend Park with permission from park staff.

Tech Tips

The following equipment was used to shoot the preceding photograph: Canon EOS 5D Mark II digital camera, in manual mode; Canon EF100mm f/2.8L Macro lens (set for manual focus) plus a Kenko 20mm macro automatic extension tube and Raynox DCR-250 close-up filter; Canon 580EX II external flash, off-camera, in manual mode; Canon 580EX external flash, off-camera, in manual mode; and a Yongnuo YN-622C-TX E-TTL II Wireless Flash Controller for Canon plus a two-pack of Yongnuo YN-622C II E-TTL Wireless Flash Transceivers for Canon.

Copyright © 2017 Walter Sanford. All rights reserved.

Swift River Cruiser (emergent female)

May 30, 2017

A Swift River Cruiser dragonfly (Macromia illinoiensis) was spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a late-stage emergent teneral female, as indicated by her terminal appendages.

Many of the major milestones during the miraculous process of emergence occurred before I spotted the dragonfly. I photographed the process from the first sighting to the time when I had to stop (see The Backstory, below): I shot 102 photos in approximately one hour; time is compressed by showcasing five (5) select photos from the first-to-last sighting.

The following photo is the first image from a time-series documenting the late-stage emergence of the teneral female. Elapsed time is expressed in hh:mm:ss format, e.g., 00:00:00 is the time when I spotted the emergent teneral female, and 01:01:15 is the total elapsed time.

27 MAY 2017 | 09:09:13 am EDT | Elapsed time: 00:00:00

The wings seem to be fully expanded (as shown in the preceding photo), evidenced by the fact that it appears some of the greenish hemolymph has been pumped out of the wings and into the abdomen.

27 MAY 2017 | 09:51:08 am EDT | Elapsed time: 00:41:55

Notice the wings are mostly clear in the following photo, in contrast with the first photo in this gallery. Next the abdomen expanded slowly until it was longer than the wings, as shown in the last photo.

27 MAY 2017 | 09:52:33 am EDT | Elapsed time: 00:43:20

As time passed, more of the adult coloration began to appear. Notice the large yellow spot on the dorsal side of abdominal segment seven (S7).

27 MAY 2017 | 09:57:39 am EDT | Elapsed time: 00:48:26

The last photo shows the dragonfly waiting for the wings and body to harden before its first flight.

27 MAY 2017 | 10:10:28 am EDT | Elapsed time: 01:01:15

The Backstory

I woke up at 4:30 a.m. in order to be at Riverbend Park when the gates open at 7 a.m. I had to attend a training session in order to be a volunteer collector of dragonfly exuviae for a research program sponsored by the park. The class started at 10 a.m., but I wanted to look around and shoot photos before the class.

I found almost nothing photo-worthy until soon after 9:00 a.m. when I spotted the emergent Swift River Cruiser dragonfly. The emergence was well underway at that point; I had to go to class before the wings spread and the teneral dragonfly flew away.

The emergence site was in a high-traffic location, so the daughter of a woman in the class guarded/watched the teneral until it flew away safely. After class, I collected the exuvia. I will shoot a set of studio macro photographs of the exuvia before returning the specimen to the park.

Swift River Cruiser is a new species of dragonfly for my life list.

Copyright © 2017 Walter Sanford. All rights reserved.

Late-stage emergent baskettail dragonfly

April 18, 2017

Common Baskettail dragonfly (Epitheca cynosura) was spotted at Painted Turtle Pond during a photowalk around Occoquan Bay National Wildlife Refuge (OBNWR), Prince William County, Virginia USA. This individual is a late-stage emergent teneral female.

I photographed the process of emergence from the first sighting to the time when the teneral dragonfly flew away: I shot 23 photos in approximately 16 minutes; time is compressed by showcasing six (6) select photos taken at major milestones during the event.

The following photo is the first image from a time-series documenting the emergence of the teneral female. Elapsed time is expressed in hh:mm:ss format, e.g., 00:00:00 is the time when I spotted the emergent teneral female, and 00:16:08 is the total elapsed time.

13 APR 2016 | 11:38:41 am EDT | Elapsed time: 00:00:00

Notice the drop of fluid at the tip of the abdomen. Emerging dragonflies pump fluid into their wings, causing the wings to expand. Next, the same fluid is withdrawn from the wings and used to expand the abdomen. Excess fluid is expelled afterward.

13 APR 2016 | 11:40:48 am EDT | Elapsed time: 00:02:07

The next photo shows the first time the wings opened.

13 APR 2016 | 11:48:55 am EDT | Elapsed time: 00:10:14

Then the wings closed again and remained closed for a while.

13 APR 2016 | 11:51:02 am EDT | Elapsed time: 00:12:21

The wings reopened a few minutes later. Notice that several wings are malformed slightly.

13 APR 2016 | 11:54:14 am EDT | Elapsed time: 00:15:33

Finally, the wings open up, and very soon the teneral adult flies away. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 468). Princeton University Press. Kindle Edition.

The teneral female dragonfly flew away immediately after the last photo in the time-series.

13 APR 2016 | 11:54:46 am EDT | Elapsed time: 00:16:08

This individual is a female, as indicated by her cerci (superior appendages) and thick abdomen. Common Baskettail females have shorter cerci and a thicker abdomen than males of the same species.

Exuviae (in situ)

Several dragonfly exuviae were spotted at Painted Turtle Pond. The exuviae were identified using a dichotomous key for dragonfly larvae; they are cast skins from Common Baskettail.

13 APR 2017 | OBNWR | Common Baskettail (exuvia)

These exuviae are not the one from which the teneral female featured in this post emerged.

13 APR 2017 | OBNWR | Common Baskettail (exuvia)

Copyright © 2017 Walter Sanford. All rights reserved.

Malformed Cobra Clubtail dragonflies

February 21, 2017

I took 255 photographs during my first photowalk along the Potomac River at Riverbend Park, Fairfax County, Virginia USA, including lots of photos of Cobra Clubtail dragonflies (Gomphurus vastus). I noticed several malformed individuals when I reviewed the entire photo set recently (in search of look-alike species of clubtail dragonflies). None of the malformations prevented the dragonflies from functioning normally.

The first Cobra Clubtail is a male with a slightly crimped right hind wing, where a small part of the wing failed to fully inflate during emergence.

The next individual is a female. Notice that abdominal segment seven (S7) was crimped during emergence. (All dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.)

The last individual is a male. Notice his left front leg is missing. The male is either malformed or he lost the leg due to injury.

A Cobra Clubtail dragonfly (Gomphurus vastus) spotted at Riverbend Park, Fairfax County, Virginia USA. This individual is a male; its left front leg is missing. Two dark face bars are field markers that can be used to differentiate Cobra Clubtail from other similar looking species of clubtails.

16 MAY 2016 | Riverbend Park | Cobra Clubtail (male, missing leg)

Two thick dark face bars are field markers that can be used to differentiate Cobra Clubtail from other similar looking species in the Family Gomphidae (Clubtails): Midland Clubtail (Gomphus fraternus) has no face bars; Splendid Clubtail (Gomphus lineatifrons) has thin dark face bars.

Tech Tips:

Shutter Priority mode was used for the first two photographs. Aperture Priority mode was used for the last photo, in order to increase the depth of field. As you can see, the depth of field at f/7.1 was insufficient for the tip of the dragonfly abdomen to be in focus. Typically, I wouldn’t publish the last photo, but I made an exception because it is the only photo I took that shows the face bars clearly.

Copyright © 2017 Walter Sanford. All rights reserved.

When things go wrong

November 30, 2016

One week after I witnessed the miraculous metamorphosis of an emergent male Common Sanddragon dragonfly (Progomphis obscuris), I was reminded that a lot can go wrong during emergence. Like the old blues standard says…

When things go wrong, go wrong with you
It hurts me too.

An emergent nymph was spotted during a photowalk along Dogue Creek at Wickford Park. The nymph was in the same position hours later, so I’m sad to say the dragonfly was stuck in its exuvia.

Related Resource: Common Sanddragon dragonfly (emergent male), a blog post by Walter Sanford featuring a time-series of photographs documenting the metamorphosis of an emergent male Common Sanddragon dragonfly on 01 June 2016 at Wickford Park.

Copyright © 2016 Walter Sanford. All rights reserved.

Common Sanddragon dragonfly (emergent male)

June 8, 2016

I was in the right place at the right time as I was photowalking Dogue Creek at Wickford Park on 01 June 2016: I noticed a dragonfly nymph as it crawled out of the water; the nymph stopped a few inches from the waterline and began to emerge right away. I photographed the entire process from beginning to end: I shot 77 photos in approximately 45 minutes; time is compressed by showcasing 14 select photos taken at major milestones during the event.

The following photo is the first image from a time-series documenting the miraculous metamorphosis of an emergent male Common Sanddragon dragonfly (Progomphis obscuris). Elapsed time is expressed in hh:mm:ss format, e.g., 00:44:21 (the total elapsed time).

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:07:51 am EDT | Elapsed time: 00:00:00

The pre-emergent dragonfly nymph appears in the lower-left corner of the preceding photo; the cast skin from another dragonfly appears in the upper-right corner. Truth be told, I was so focused on observing the dragonfly nymph that I never noticed the cast skin until after I finished the photoshoot!

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:09:33 am EDT | Elapsed time: 00:01:42

The dragonfly began to emerge through a split in the thorax, as shown in the next three photos.

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:15:07 am EDT | Elapsed time: 00:07:16

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:15:36 am EDT | Elapsed time: 00:07:45

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:16:16 am EDT | Elapsed time: 00:08:25

Within minutes, the emergent dragonfly was entirely free from its exoskeleton. This individual is a male, as indicated by his terminal appendages.

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:21:01 am EDT | Elapsed time: 00:13:10

The wings, folded like accordions, then begin to fill from the base with fluid transferred from the body and fairly soon reach full length. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 466-467). Princeton University Press. Kindle Edition.

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:22:03 am EDT | Elapsed time: 00:14:12

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:23:06 am EDT | Elapsed time: 00:15:15

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:25:22 am EDT | Elapsed time: 00:17:31

Soon, the folded wings were as long as the abdomen…but that didn’t last long.

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:31:02 am EDT | Elapsed time: 00:23:11

The fluid is then pumped back into the abdomen, and it expands. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 467-468). Princeton University Press. Kindle Edition.

Notice the wings are nearly clear in following photo, indicating the greenish-colored fluid that formerly filled the wings is almost gone. The abdomen is noticeably longer than the wings in this photo.

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:34:48 am EDT | Elapsed time: 00:26:57

Finally, the wings open up, and very soon the teneral adult flies away. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 468). Princeton University Press. Kindle Edition.

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:36:42 am EDT | Elapsed time: 00:28:51

The next-to-last photo shows the teneral dragonfly after waiting approximately 15 minutes for its wings to harden, just before first flight…

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:51:32 am EDT | Elapsed time: 00:43:41

The last photo shows the cast skin from the emergent dragonfly, technically known as an exuvia (singular). The white filaments that extend from the split in the thorax are breathing tubes, artifacts of the unique respiratory system of dragonfly nymphs.

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | 10:52:12 am EDT | Elapsed time: 00:44:21

Related Resources:

  • Metamorphosis of a dragonfly – a blog post by Mike Powell documenting an emergent Common Sanddragon dragonfly observed on 03 June 2016 at Huntley Meadows Park
  • Emerging Common Sanddragons – a blog post by Walter Sanford featuring two emergent Common Sanddragon dragonflies observed at Patuxent Research Refuge
  • Miraculous metamorphis – a blog post by Walter Sanford documenting an emergent female Common Whitetail dragonfly at Huntley Meadows Park

Copyright © 2016 Walter Sanford. All rights reserved.

Miraculous metamorphosis

May 11, 2016

I was sitting on my Coleman camp stool on the earthen dam at Hidden Pond, Meadowood Recreation Area, hoping the sky would clear so I could see some odonates. The sky was almost completely overcast; as a result, I hadn’t seen any dragonflies or damselflies all morning.

My cell phone rang. Matt Ryan, a good friend and part-time naturalist at Huntley Meadows Park, called to tell me about a dragonfly larva he spotted that had just started to transform into an adult. I was conflicted for a few minutes: Meadowood Recreation Area is much farther from my home than Huntley Meadows Park so I was reluctant to leave empty-handed, so to speak, especially since several species of odonates can be seen at Meadowood that aren’t known to occur at Huntley. Fortunately I came to my senses and drove to Huntley as quickly as possible.

The following photo is the first image from a three-hour time-series documenting an emergent female Common Whitetail dragonfly (Plathemis lydia), located within a few feet from the boardwalk in the central wetland area at Huntley Meadows Park. The miraculous metamorphosis was well underway by the time I arrived at the spot. Elapsed time is expressed in hh:mm:ss format.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 11:21 am EDT | Elapsed time: 00:00:00

The wings, folded like accordions, then begin to fill from the base with fluid transferred from the body and fairly soon reach full length. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 466-467). Princeton University Press. Kindle Edition.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 11:32 am EDT | Elapsed time: ~00:11:00

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 12:20 pm EDT | Elapsed time: ~00:59:00

The fluid is then pumped back into the abdomen, and it expands. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 467-468). Princeton University Press. Kindle Edition.

Notice the wings are nearly clear in following photo, indicating the greenish-colored fluid that formerly filled the wings is almost gone. The abdomen is noticeably longer in this photo than in the first image in the time-series, taken at 11:21 EDT.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 12:43 pm EDT | Elapsed time: ~01:22:00

At this point, a pair of terminal appendages (cerci) was clearly visible at the end of the abdomen, indicating this individual is a female.

Notice the wing spots are beginning to darken. 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.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 01:23 pm EDT | Elapsed time: ~02:02:00

Finally, the wings open up, and very soon the teneral adult flies away. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 468). Princeton University Press. Kindle Edition.

The pair of wings on her right side snapped into the resting position approximately two hours and 18 minutes (~02:18:00) after I started this time-series of photos.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 01:38:42 pm EDT | Elapsed time: 02:17:42

The pair of wings on her left side snapped into the resting position one minute and four seconds (00:01:04) later.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 01:39:46 pm EDT | Elapsed time: 02:18:46

Her wings quivered slightly at ~02:24:00 pm and then she flew away.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 02:24 pm EDT | Elapsed time: ~03:03:00

The last photo shows the cast skin from the emergent dragonfly, technically known as an exuvia (singular).

A cast skin from a Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This is the exuvia of an emerging female.

07 MAY 2016 | 02:28 pm EDT | Elapsed time: ~03:07:00

Although I have seen two emerging dragonflies from a different family, albeit briefly, and seen several exuviae (plural) in situ, this was my first opportunity to observe the process carefully for several hours. Sincere thanks to Matt Ryan for kindly thinking of me!

Copyright © 2016 Walter Sanford. All rights reserved.

Emerging Common Sanddragons

June 29, 2014

Two emerging Common Sanddragon dragonflies (Progomphus obscurus) were spotted on 15 June 2014 during the “Advanced Dragonfly Studies” adult class and field trip to the Patuxent Research Refuge. The field trip was led by Richard Orr, renowned expert on odonates of the mid-Atlantic region, and Stephanie Mason, Senior Naturalist, Audubon Naturalist Society.

emerge: to leave water and undergo metamorphosis into an adult; emergence is thus both from water and from exuvia Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 11593-11594). Princeton University Press. Kindle Edition.

The first two photos show a sanddragon emerging from its exuvia (plural exuviae), also known as a “cast skin.” Notice that its wings have not started expanding.

Common Sanddragon dragonfly (emerging, teneral, exuvia)

Common Sanddragon dragonfly (teneral, exuvia)

The wings, folded like accordions, then begin to fill from the base with fluid transferred from the body and fairly soon reach full length. The fluid is then pumped back into the abdomen, and it expands. Finally, the wings open up, and very soon the teneral adult flies away. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 466-468). Princeton University Press. Kindle Edition.

The last photo shows a teneral adult (upper right) and its exuvia (lower left). Since it takes approximately 30 minutes for dragonfly wings to expand, we can infer this sanddragon emerged before the other one.

Common Sanddragon dragonfly (teneral, exuvia)

Copyright © 2014 Walter Sanford. All rights reserved.


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