Posts Tagged ‘Family Corduliidae (Emeralds)’

Final Fine-lined Emerald

October 7, 2019

Several Fine-lined Emerald dragonflies (Somatochlora filosa) were spotted during a photowalk with Michael Powell at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. At least six S. filosa were spotted along two dirt/gravel roads at the refuge; this is the last one we saw.

This individual is a male, as indicated by his “indented” hind wings and terminal appendages.

Decisions, decisions!

I shot 37 photographs of the following dragonfly perched in several places: two photos are out of focus; most of the rest are flawed in some way (in my opinion), for example I don’t like the background, or the composition, etc.

As it turns out, the last group of photos is my favorite. Within that group, I selected a subset of three photos that I like. Although the photos are similar, they are subtly different. I think one of the images is the clear winner, but I suffer from decision paralysis sometimes. The photos are shown in the order in which they were taken. Which one is your favorite?

No.1

No. 2

No. 3

Sidestory

I think I might have figured out the habitat/breeding habitat for Fine-lined Emerald dragonflies. As Mike Powell and I were walking along one of several roads at Occoquan Bay NWR that lead to hotspots for hunting Fine-lined Emerald, I noticed shallow pools of “black water” in the forest, beginning about halfway down one of the dirt/gravel roads at the park. I mentioned to Mike that I think the black water pools are habitat for S. filosa.

Sure enough, that’s exactly where we spotted the male featured in this post — the last one we saw as we were walking back to Mike’s car. It’s worth noting we have never seen a Fine-lined Emerald that far from the main hotspots. Mike saw several more S. filosa in the same area a few days later. Hey, I might be onto something!

Copyright © 2019 Walter Sanford. All rights reserved.

Yet another male Fine-lined Emerald

September 30, 2019

The following images show the third Fine-lined Emerald dragonfly (Somatochlora filosa) that I photographed during a photowalk on 18 September 2019 at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

This individual is a male, as indicated by his “indented” hind wings and terminal appendages. The following photo shows both field marks clearly.

Personality

Do dragonflies have personality? Who knows? I’ll say this: Some individuals within the same species seem to behave in ways that are distinctly observable and slightly atypical.

For example, this guy was hyperactive. He flew from perch-to-perch as though he were searching for the perfect perch. After brief stops at several spots, he disappeared into the tree canopy.

Before Mike Powell and I spotted the male featured in this post, we watched another male patrol back-and-forth between us for more than 30 minutes without landing! Mike and I were standing along a dirt/gravel road, about 20-30 yards apart. We had a lot of fun “redirecting” the dragonfly in the opposite direction toward each other. Several times the dragonfly “pulled up” in front of me and appeared to be thinking about landing on my head, but we were never so lucky. Eventually, the male must have tired of the game because he simply vanished!

Perhaps I’m guilty of personification of dragonflies, but I think they have lots of personality!

Copyright © 2019 Walter Sanford. All rights reserved.

Another male Fine-lined Emerald

September 25, 2019

The following gallery shows the second Fine-lined Emerald dragonfly (Somatochlora filosa) that I photographed during a photowalk on 18 September 2019 at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

This individual is a male, as indicated by his “indented” hind wings and terminal appendages. The following photo shows both field marks clearly.

Male Fine-lined Emerald dragonflies typically patrol back-and-forth along relatively short segments, about waist high; in this case, they were patrolling along dirt/gravel roads in the forest. They perch about head high on tall grasses or bare tree branches.

Copyright © 2019 Walter Sanford. All rights reserved.

Fine-lined Emerald dragonfly (male)

September 20, 2019

A Fine-lined Emerald dragonfly (Somatochlora filosa) was spotted during a photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. Several specimens were spotted along two dirt/gravel roads at the refuge; this is the first one I saw.

This individual is a male, as indicated by his “indented” hind wings and terminal appendages.

Adult Flight Period

According to records for the Commonwealth of Virginia maintained by Dr. Steve Roble, Staff Zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage, the adult flight period for S. filosa is from July 10 to October 15. The species is classified as rare to uncommon. Its habitat is “boggy streams, swamps, and marshes.”

Bear in mind, Dr. Roble’s records are for the entire state, therefore the adult flight period for S. filosa seems to be longer than it is in reality. The adult flight period for a single site is probably shorter. For example, according to records for Northern Virginia maintained by Kevin Munroe, former manager of Huntley Meadows Park, the adult flight period for Fine-lined Emerald is August 23 to October 04.

Rare to Uncommon

A distribution map of official records for Fine-lined Emerald helps to illustrate its classification as a rare to uncommon species of odonate.

Source Credit: Abbott, J.C. 2006-2019. OdonataCentral: An online resource for the distribution and identification of Odonata. Available at http://www.odonatacentral.org. (Accessed: September 19, 2019).

Key: blue dots = Dot Map Project; green dots = Accepted records; yellow dots = Pending records.

Related Resource: Posts tagged ‘Fine-lined Emerald dragonfly’

Copyright © 2019 Walter Sanford. All rights reserved.

Baskettail dragonflies

May 10, 2019

Several species of baskettail dragonflies (Epitheca sp.) are among the first odonates to emerge in spring.

22 APR 2019 | PRR | baskettail dragonfly (Epitheca sp.)

Two baskettail dragonflies, possibly either Common Baskettail (E. cynosura) or Slender Baskettail (E. costalis), were spotted at the North Tract of Patuxent Research Refuge, Anne Arundel County, Maryland USA.

Look closely at the full-size version of the following photo. Notice the leading edge of the left fore-wing is slightly malformed.

22 APR 2019 | PRR | baskettail dragonfly (Epitheca sp.)

[Baskettails] have proven to be very difficult to identify, particularly from photographs. Most species are quite variable and there is evidence that they may hybridize and or integrade, making identifications even tougher. Source Credit: Identification of Male Epitheca (Tetragoneuria) in Texas, by John C. Abbott.

I’m unable to identify these dragonflies to the species level. In fact, I’m not sure they’re the same species! I defer to odonate hunters with more expertise than me for help with identification of both species and gender.

Post Addendum

According to Michael Boatwright, founder and administrator of the Virginia Odonata Facebook group, both individuals are male Common Baskettail. Male Common- and Slender Baskettail have curved cerci; females of both species have straight cerci. That’s good baskettail knowledge, Mike Boatwright!

Copyright © 2019 Walter Sanford. All rights reserved.

Beware of dismissive thinking!

April 26, 2019

An unknown species of teneral baskettail dragonfly (Epitheca sp.), possibly either Common Baskettail (E. cynosura) or Robust Baskettail (E. spinosa), was spotted near a mid-sized pond at the North Tract of Patuxent Research Refuge, Laurel, Maryland USA.

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

That’s a very wide abdomen, hairy thorax, and cerci as long (if not slightly longer) as S9. I’m fairly confident it’s a Robust Baskettail but I have limited experience with that species. The pattern of dark spots at the wing base is definitive for Robust but I can’t see them well in your picture. Mike Moore’s opinion would he good. Source Credit: Michael Boatwright, founder and administrator of the Virginia Odonata Facebook group.

I consulted Dr. Michael Moore.

It certainly suggests Robust based on the dimensions of the abdomen and the “hairiness” of the thorax but I would really need to see the pattern of black at the base of the hind wings to be sure. Female Commons can be surprisingly fat. Source Credit: Dr. Michael Moore, a professor in the Department of Biological Sciences at University of Delaware and odonate expert extraordinaire. Dr. Moore’s new Web site is a treasure trove of helpful resources.

The reason neither Mike nor Michael can see the definitive field mark on the base of the baskettail dragonfly’s hind wings is because this individual is a late-stage emergent teneral and its wings haven’t opened.

Regardless of the species of dragonfly, emergence is an essentially identical process. See “Related Resources” (below) for a time-series of photographs showing part of the process of emergence for a female Common Baskettail.

The danger of dismissive thinking.

This sighting was another reminder of one of many “Walterisms”: “Don’t be dismissive!” Huh?

During a recent trip to the Patuxent Research Refuge in search of Harlequin Darner (G. furcillata), my good friend Mike Powell and I saw many basktettails, mostly Common Baskettail. Common. That’s the key word. When I noticed several baskettails, I thought, “Oh, Common Baskettails. Nothing to see here, folks. Move along. Must find Harlequin!”

As it turns out, my laser-like focus on finding my first Harlequin Darner might have caused me to miss an opportunity to see a Robust Baskettail — another new species for my life list of odonates. Once again I’m reminded that dismissive thinking can be wrong-headed.

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

Uhler’s Sundragon (female)

April 19, 2019

A Uhler’s Sundragon (Helocordulia uhleri) was spotted during a photowalk along a mid-size stream at an undisclosed location in Northern Virginia USA.

This individual is a female, as indicated by her rounded hind wings and terminal appendages. All female dragonflies have a pair of cerci (superior appendages) that have little or no function. Both cerci are visible clearly in the full-size version of the following photo.

16 APR 2019 | Northern Virginia | Uhler’s Sundragon (female)

Notice the right hind wing is slightly malformed. It appears the wing failed to inflate completely during emergence. The malformation didn’t impair her ability to fly. Pollen (probably tree pollen) is especially noticeable on the darker parts of the body.

Just the facts, ma’am.

According to records for the Commonwealth of Virginia maintained by Dr. Steve Roble, Staff Zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage, the adult flight period for H. uhleri is 29 March to 27 June. The species is classified as common. Its habitat is “streams.”

Bear in mind, Dr. Roble’s records are for the entire state, therefore the adult flight period for H. uhleri seems to be longer than it is in reality. The adult flight period for a single site is probably no more than a month, and more likely around two-to-three weeks. For example, according to records for Northern Virginia maintained by Kevin Munroe, former manager of Huntley Meadows Park, the adult flight period for Uhler’s is 11 April to 05 May.

It’s also worth noting that the window of opportunity to see Uhler’s Sundragon closes rapidly after trees are in full leaf.

Is Uhler’s Sundragon common? I guess the answer to that question depends upon where you live. In Northern Virginia, Kevin Munroe classified H. uhleri as “rare.” In fact, I’m aware of only one location in Northern Virginia where Uhler’s Sundragon can be found with reasonable certainty.

Copyright © 2019 Walter Sanford. All rights reserved.

Uhler’s Sundragon (male)

April 17, 2019

A Uhler’s Sundragon (Helocordulia uhleri) was spotted during a photowalk along a mid-size stream at an undisclosed location in Northern Virginia USA. Uhler’s Sundragon is a new species for my life list of odonates.

16 APR 2019 | Northern Virginia | Uhler’s Sundragon (male)

This individual is a male, as indicated by its “indented” hind wings and terminal appendages.

Off-season Homework Pays Dividends

Planning for the next season is a good way to stay connected with odonates during the winter months. One off-season activity that can pay big dividends in the future is to research sites for finding new life-list species of dragonflies and damselflies, especially rare and uncommon species.

Uhler’s is No. 1 on my list of target species for 2019. During the winter of 2018-2019, I researched potential sites for finding Uhler’s Sundragon. I’m pleased to report “Mission accomplished!”

Credits

I’ve been dogged by, er, let’s just say “transportation issues” for months. Sincere thanks to my buddy Mike Powell for scouting one of the sites I researched and guiding me to a couple spots where he found Uhler’s. Good work, Mike — couldn’t have done it without you!

Also thanks to Michael Boatwright, founder and administrator of the Virginia Odonata Facebook group, for providing lots of practical tips for finding Uhler’s Sundragon in the field.

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

“Generic Baskettail” (definitely not a Cruiser)

February 18, 2019

larva/nymph in the Family Corduliidae (Emeralds) was collected by Bob Perkins on 02 December 2017 from a pond in Orange Park, Florida (USA). The larva died before it metamorphosed into an adult.

As you can see by looking at a close-up image of the face-head at 3x magnification, there is no horn on the face of the specimen. Therefore this individual is not a member of Family Macromiidae (Cruisers), as I speculated in my last blog post.

“Generic Baskettail” larva (preserved specimen) | face-head

Knowing the limits of our expertise

Although I still need to key out the specimen carefully, at this point I’m certain Bob is correct — the larva is a member of the Family Corduliidae (Emeralds). The question that remains unanswered is “Which genus/species?” We may never know the answer, as Bob and I have reached the limit of our experience and expertise.

I did a quick scan of Paulson’s [book], looking at the Emerald Family. Here, according to the range maps, are the possibilities for Orange Park [FL]. I believe you can see why I stopped at “generic basketttail.” Source Credit: Bob Perkins.

What do you think the identity is? Most of the items in the preceding species list feature links to photos of odonate larvae/exuviae. See the links to BugGuide from the scientific names in the list.

Related Resource: Test shots: “Generic Baskettail?”

Tech Tips

Four (4) photos were used to create the preceding focus-stacked composite image. A single focus point was positioned over the face, between the antennae. At a magnification ratio of 3:1, it’s difficult to manually focus on a single point — the slightest movement around the macro rig changes focus unintentionally. A simple work-around for this problem is to take several shots of the same focus point and create a composite image of the photos.

The following equipment was used to shoot the preceding composite image: Canon EOS 5D Mark II digital camera, in manual mode; Canon MP-E 65mm Macro lens (set for f/16 at 3x); a Canon MT-26EX-RT Macro Twin Lite set for “Master” mode, and a single external flash set for “Slave” mode — a Godox TT685C Thinklite TTL Flash fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier. A Sunpak LED-160 Video Light was used to add fill light to the top of the subject.

Auto power-off was disabled for the camera and external flash units.

Adobe Photoshop CC 2017 was used to create the focus stack, as well as spot-heal and sharpen the final output.

Copyright © 2019 Walter Sanford. All rights reserved.

Test shots: “Generic Baskettail?”

February 15, 2019

larva/nymph in the Family Corduliidae (Emeralds) was collected by Bob Perkins on 02 December 2017 from a pond in Orange Park, Florida (USA). The larva died before it metamorphosed into an adult.

Test shots of this beautifully preserved specimen were taken using a small-ish aperture of f/11 for greater depth of field. The following photos are “one-offs,” that is, not composite images.

Dorsal

A single focus point — located on the thorax (specifcally, the “shoulder pad” along the right side of the body) — was used to shoot this photo. The specimen has enough “relief” that focus on the wing pads and dorsal hooks is slightly soft. This view of the larva is a good candidate for focus-stacking.

The terminal appendages (cerci, epiproct, paraprocts) are shown clearly in the following photo.

“Generic Baskettail” larva (preserved specimen) | Orange Park, FL USA

Bob’s best guess of the identity of the specimen is Epitheca sp., either Common Baskettail (Epitheca cynosura) or Prince Baskettail (Epitheca princeps).

Whenever I see an odonate larvae/exuviae with long legs, my first thought is Family Macromiidae (Cruisers). Then I check for a horn on top of the head, a key field marker for Cruisers. Look closely at the dorsal view of the larva and I think you’ll agree with me there appears to be a horn on the head. I would like to take close-up photos of the head and key out the specimen in order to determine its identity. In the meantime, my best guess is Stream Cruiser (Didmops transversa) as indicated by the lateral spines on abdominal segment nine (S9) and the absence of a dorsal hook on S10.

Ventral

The ventral side of the specimen has almost no “relief,” so a “one-off” focused on the thorax looks fairly good from head-to-tail.

“Generic Baskettail” larva (preserved specimen) | Orange Park, FL USA

Related Resource: “Generic Baskettail” (definitely not a Cruiser)

Tech Tips

The following equipment (shown below) was used to shoot the preceding photos: Fujifilm X-T1 digital camera; Fujifilm MCEX-16 extension tube; Fujinon XF80mm macro lensGodox XProF TTL Wireless Flash Trigger for Fujifilm camerasGodox TT685F Thinklite TTL Flash for Fujifilm CamerasGodox TT685C Thinklite TTL Flash for Canon Cameras fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier; and a Canon 580EX II Speedlite mounted on a Godox X1R-C TTL Wireless Flash Trigger Receiver for Canon. A new Godox TT685O Thinklite TTL Flash for Olympus/Panasonic Cameras was added to an array of radio-controlled external flash units used to light the specimen. All flashes were set for Manual Mode at 1/128 power.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen the final output.

Copyright © 2019 Walter Sanford. All rights reserved.


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