18 AUG 2020 | JMAWR | Slaty Skimmer (male)
The preceding photo shows a Slaty Skimmer dragonfly (Libellula incesta) that was spotted during a photowalk with Michael Powell near Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR) in Fairfax County, Virginia USA.
This individual is a mature male, as indicated by his coloration, tattered wings, and terminal appendages.
Copyright © 2020 Walter Sanford. All rights reserved.
The following photo shows a Slaty Skimmer dragonfly (Libellula incesta) that was spotted during a photowalk with Michael Powell near Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR) in Fairfax County, Virginia USA.
This individual is a mature male, as indicated by his coloration and terminal appendages.
18 AUG 2020 | JMAWR | Slaty Skimmer (male)
This mature male has mated many times, as indicated by the scratches on his abdomen.
Males that have mated often have marks on their abdomen where the female legs have scratched them. This is especially obvious in species in which males develop pruinosity, as the pruinosity on the mid-abdomen is scratched off, and the signs are visible at some distance. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 390-392). Princeton University Press. Kindle Edition.
Copyright © 2020 Walter Sanford. All rights reserved.
Like the Singing Cowboy Gene Autry sang, I’m black in the saddle again. OK, maybe more like blue-black — either way I’m back baby!
18 AUG 2020 | JMAWR | Slaty Skimmer (male)
The preceding photo shows a Slaty Skimmer dragonfly (Libellula incesta) that was spotted during a photowalk with Michael Powell near Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR) in Fairfax County, Virginia USA. This individual is a mature male, as indicated by his coloration and terminal appendages.
This is the second photo I shot at the outset of the photowalk — the first photo was a little too dark because the external flash power ratio was a little too low. Most external flash units work with most cameras as long as the flash is set for Manual mode. Some trial and error is necessary to get the proper exposure. 1/16 power is a good starting point — that way the best power ratio is usually no more than two- to three stops away.
Copyright © 2020 Walter Sanford. All rights reserved.
Michael Powell spotted a Slaty Skimmer dragonfly (Libellula incesta) during a photowalk with me along a mid-size stream in Fairfax County, Virginia USA.
This individual is a mature male, as indicated by his coloration, hamules, and terminal appendages.
15 JUL 2020 | Fairfax County, VA | Slaty Skimmer (male)
After a long day of searching for Eastern Least Clubtails (Stylogomphus albistylus) unsuccessfully — an uncommon species of dragonfly — it was good to see any type of dragonfly, including a common species like Slaty Skimmer!
Slaty Skimmer is a habitat generalist that can be found almost anywhere there is water.
Post Update
You know, sometimes I look at a full-frame photo and think it would look better cropped slightly. This is one of those times. So I cropped the photo and think it looks much better than the full-frame version. What do you think?
15 JUL 2020 | Fairfax County, VA | Slaty Skimmer (male)
Copyright © 2020 Walter Sanford. All rights reserved.
With each new photo set of this unknown species of odonate exuvia, a case is building slowly for Slaty Skimmer (Libellula incesta).
Occoquan Regional Park | unknown species | exuvia (lateral)
A piece of white schmutz was removed from the tip of the abdomen, enabling a clearer view of abdominal segment nine (S9). Look closely at the two photos featured in this post. Notice there are stubby mid-dorsal hooks (not cultriform) on abdominal segments four through eight (S4-S8).
Occoquan Regional Park | unknown species | exuvia (dorsal)
The last photo shows a closer view of the anal pyramid. Notice the lateral caudal appendages (cerci) are less than half as long as the inferior appendages (paraprocts).
Soltesz, p. 43 – Key to the Species of the Genus Libellula
Field marks that match this specimen are highlighted in boldface green text.
1b. Dorsal hooks regularly present on segments 4 to 8. [2]
2b. Palpal setae 5 (sometimes 6 in cyanea). [5]
5a. Epiproct distinctly decurved at tip. [6]
6b. Length of last instar about 26mm; cerci less than half as long as paraprocts. [incesta]
Punch List
I need to look at the inside of the labium (face mask) in order to count palpal setae. The epiproct must be cleaned to see whether it is decurved. This exuvia was deformed as a result of emergence, so it’s impossible to make an accurate measurement of the length of the specimen. That said, the exuvia is more than 22.0 mm (0.9 in) long. (22 mm is the length of the last instar for L. cyanea.)
And of course, I need to annotate all of the images in this series of blog posts in order to illustrate the unfamiliar vocabulary that is used in virtually all dichotomous identification keys.
Related Resources
Tech Tips
The following equipment was used to shoot the quick-and-dirty macro photographs featured in this post: Fujifilm X-T1 digital camera; Fujifilm MCEX-16 extension tube; and Fujinon XF80mm macro lens plus lens hood. The camera was set for both manual exposure and manual focus. That’s right, a switch on the camera body is used to set the type of focus. It’s a Fujifilm thing. Camera settings: focal length 80mm (120mm, 35mm equivalent); ISO 200; f/16; 1/180s.
A Godox X2TF radio flash trigger, mounted on the hotshoe of my X-T1, was used to control two off-camera external flash units set for radio slave mode: Godox TT685F Thinklite TTL Flash (manual mode); and Godox TT685o/p Thinklite Flash for Olympus/Panasonic Cameras (manual mode). Both flash units were fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.
Adobe Photoshop CC 2017 was used to spot-heal and sharpen the image.
Copyright © 2019 Walter Sanford. All rights reserved.
This post features another photo of an odonate exuvia collected by Michael Powell during a photowalk with me on 01 June 2019 at Occoquan Regional Park, Fairfax County, Virginia USA. The photo is a one-off (not a composite image) showing the ventral view of the exuvia.
The genus and species is unknown. This specimen might be a member of Family Libellulidae (Skimmers), probably Slaty Skimmer (Libellula incesta).
Occoquan Regional Park | unknown species | exuvia (ventral)
Related Resource: Vimeo video: Identifying dragonfly larva to family (8:06).
Tech Tips
The following equipment was used to shoot the quick-and-dirty macro photograph featured in this post: Fujifilm X-T1 digital camera; Fujifilm MCEX-16 extension tube; and Fujinon XF80mm macro lens plus lens hood. The camera was set for both manual exposure and manual focus. That’s right, a switch on the camera body is used to set the type of focus. It’s a Fujifilm thing. Camera settings: focal length 80mm (120mm, 35mm equivalent); ISO 200; f/16; 1/180s.
A Godox X2TF radio flash trigger, mounted on the hotshoe of my X-T1, was used to control two off-camera external flash units set for radio slave mode: Godox TT685F Thinklite TTL Flash (manual mode); and Godox TT685o/p Thinklite Flash for Olympus/Panasonic Cameras (manual mode). Both flash units were fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.
Adobe Photoshop CC 2017 was used to spot-heal and sharpen the image.
Copyright © 2019 Walter Sanford. All rights reserved.
A Slaty Skimmer dragonfly (Libellula incesta) was spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.
This individual is a mature male, as indicated by his dark coloration and terminal appendages.
16 AUG 2019 | Occoquan Bay NWR | Slaty Skimmer (mature male)
Habitat preference
Slaty Skimmer is a habitat generalist that can be found virtually anywhere there is water, such as a mid-size pond like Painted Turtle Pond.
This species is a true habitat generalist; only whitetails and pondhawks can be found in as many different habitat types. I’ve seen Slaties along river edges, sunny sections of woodland streams, ponds, lakes, swamps, old roads and flooded meadows. Dragonflies of summer, if you’re in any of these habitats June through September, you’re likely to come face to face with a Slaty Skimmer. Source Credit: Dragonflies of Northern Virginia, by Kevin Munroe.
Copyright © 2019 Walter Sanford. All rights reserved.
Several test photos were taken for an upcoming identification guide for exuviae from Slaty Skimmer dragonfly (Libellula incesta).
The exuvia has a mask-like labium with smooth crenulations, indicating this specimen is a member of the Family Libellulidae (Skimmers), the largest family of dragonflies.
No. 1 | Libellula incesta | exuvia (face-head-dorsal)
Also notice the exuvia has “pointed” eyes, rather than “rounded” eyes like the exuvia from a Carolina Saddlebags dragonfly (Tramea carolina) shown below.
No. 2 | Tramea carolina | exuvia (face-head)
The pointed- versus rounded eyes dichotomy is a somewhat subjective decision, but if you make the right choice then this field mark can be used to narrow the range of possible Libellulidae genera.
Exuviae from three genera of Libellulidae have pointed eyes: Libellula (18 species); Orthemis (3 species); and Plathemis (2 species). Slaty Skimmer (Libellula incesta) is one of 18 species in the genus Libellula.
Exuviae from all other genera of Libellulidae have rounded eyes.
No. 3 | Libellula incesta | exuvia (dorsal)
This specimen needs to be rehydrated/relaxed in order to remove some distracting debris and reposition the legs for better photo poses.
No. 4 | Libellula incesta | exuvia (ventral)
To be continued…
The Backstory
A Slaty Skimmer dragonfly (Libellula incesta) nymph was collected by Bob Perkins on 29 May 2017 along Pine Creek in Carroll County, Virginia USA. The nymph was reared in captivity until it emerged on 29 June 2017 and metamorphosed into an adult male. This specimen is the exuvia from the nymph.
Copyright © 2018 Walter Sanford. All rights reserved.
Several Slaty Skimmer dragonflies (Libellula incesta) were spotted during a photowalk along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is a male, as indicated by his terminal appendages and slaty blue coloration.
09 JUL 2017 | Wickford Park | Slaty Skimmer (male)
This guy was my constant companion while I was photographing a male Common Sanddragon perching on a small sandbar in the creek.
09 JUL 2017 | Wickford Park | Slaty Skimmer (male)
I nicknamed this dragonfly “The Blue Boy” because his rich blue-indigo color is reminiscent of an oil painting by Thomas Gainsborough.
Copyright © 2017 Walter Sanford. All rights reserved.
Refer to the Dragonflies of Northern Virginia Calendar of Flight Periods by Kevin Munroe, former manager at Huntley Meadows Park. Notice the flight period for most Skimmers (Family Libellulidae) is centered on June, July, and August. Since meteorological summer is defined as June, July, and August, summertime is skimmer time.
17 JUL 2017 | Occoquan Bay NWR | Slaty Skimmer (female)
A female Slaty Skimmer dragonfly (Libellula incesta) was spotted during a photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA, as indicated by her mostly black femora, brown face, and terminal appendages.
Female Slaty Skimmers have a pair of flanges beneath their eighth abdominal segment (S8) that are used to scoop water when laying eggs (oviposition), hence the family name “Skimmer.”
17 JUL 2017 | Occoquan Bay NWR | Slaty Skimmer (female)
Female Slaty Skimmer dragonflies and female Great Blue Skimmer dragonflies (Libellula vibrans) look similar. The following blog post provides guidance regarding key field marks that can be used to differentiate the two species: Great Blue Skimmer dragonfly (young female).
Copyright © 2017 Walter Sanford. All rights reserved.
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