Posts Tagged ‘epiproct’

Post update: Phanogomphus lividus exuvia

April 13, 2018

Phanogomphus lividus exuvia, my identification guide for Ashy Clubtail exuviae, was updated to feature two new annotated high-magnification macro composite images.

  • Photo No. 1: The specimen was rehydrated/relaxed in order to reposition the front legs for an unobstructed view of the prementum, especially the median lobe of the labium.
  • Photo No. 2: A close-up view of the anal pyramid (terminal appendages) verified the “superior caudal appendage (epiproct) is as long as inferiors (paraprocts).”

The first image is a composite of six photos that shows a ventral view of the prementum.

Editor’s Note: Sincere thanks to Sue and John Gregoire for guiding me to the location of the median lobe.

The last image is a composite of 15 photos that shows a dorsal view of the abdomen; the inset image is a selection from a composite of 10 photos that shows a ventral view of the anal pyramid.

No. 2 | Ashy Clubtail (Phanogomphus lividus) | exuvia (anal pyramid)

The Backstory

An Ashy Clubtail dragonfly (Phanogomphus lividusnymph was collected by Bob Perkins. (The date and location where the specimen was collected are unknown.) The nymph was reared in captivity until it emerged on 21 March 2017 and metamorphosed into an adult female. This specimen is the exuvia from the nymph. P. lividus is a member of the Family Gomphidae (Clubtails).

Tech Tips

The following equipment was used to shoot all of the photos for the preceding composite images: Canon EOS 5D Mark II digital camera, in manual mode; Canon MP-E 65mm Macro lens (manual focus only, set for f/8 at either 2x or ~3x magnification); Canon MT-26EX-RT Macro Twin Lite set for “Master” mode; and Canon 580 EX- and Canon 580EX II Speedlites in “Slave” mode.

Adobe Photoshop CC 2017 was used to create the composite image by “round-tripping” with Apple Aperture.

Copyright © 2018 Walter Sanford. All rights reserved.

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Phanogomphus lividus exuvia

April 5, 2018

The Backstory

An Ashy Clubtail dragonfly (Phanogomphus lividusnymph was collected by Bob Perkins. (The date and location where the specimen was collected are unknown.) The nymph was reared in captivity until it emerged on 21 March 2017 and metamorphosed into an adult female. This specimen is the exuvia from the nymph. P. lividus is a member of the Family Gomphidae (Clubtails).

A two-step process was used to verify the identity of the exuvia.

  1. Determine the family.
  2. Determine the genus and species.

Step 1. Family

First, determine the family of the specimen. For reference, watch the excellent Vimeo video Identifying dragonfly larva to family (8:06). Here’s the decision tree used to identify the exuvia as a member of the Family Gomphidae (Clubtails).

  • The specimen has a flat labium that doesn’t cover the face (not mask-like), as shown in Photo No. 1 and 3.
  • Antennae are club-like (not thin and thread-like, as in  Aeshnidae larvae), as shown in Photo No. 1.

It’s simple and straightforward to recognize this specimen is a clubtail.

No. 1 | Ashy Clubtail (Phanogomphus lividus) | exuvia (face-head)

Step 2. Genus and species

Lateral spines are present on abdominal segments six through nine (S6-S9).

The superior caudal appendage (epiproct) is as long as inferiors (paraprocts), as shown in Photo No. 4. The view of the terminal appendages is still slightly obscured by debris after the specimen was cleaned, making it challenging to distinguish the cerci from the paraprocts. Nonetheless, the epiproct and paraprocts appear to be nearly the same length.

The median lobe of the labium (prementum) is straight-edged, as shown in Photo No. 5.

After emergence

The next photograph shows the Ashy Clubtail dragonfly after emergence from one of Bob Perkins‘ holding tanks. Phanogomphus lividus is 48-56 mm in total length (Paulson, 2011).

Image used with permission from Bob Perkins.

This individual is a female, as indicated by its rounded hind wings and terminal appendages.

Image used with permission from Bob Perkins.

Related Resource

The dichotomous key for Gomphus (now Phanogomphus) that appears on p. 20 in Identification Keys to Northeastern Anisoptera Larvae, compiled by Ken Soltesz, was used to attempt to verify the genus and species of the exuvia. Markers that match this specimen are highlighted in boldface green text. Three boldface green asterisks (***) are used to highlight the thread for identification of P. lividus. Disclaimers are highlighted in boldface red text.

1a. Lateral spines on abdominal segments 7 to 9 (very minute if present on 6). [2]
***1b. Lateral spines on abdominal segments 6 to 9 well developed. [3]

3a. Superior caudal appendage (epiproct) shorter than inferiors (paraprocts); Teeth on lateral lobes of labium obsolete or poorly developed. [quadricolor]
***3b. Superior caudal appendage (epiproct) as long as inferiors (paraprocts); Teeth on lateral lobes of labium well developed. [4]

***4a. Median lobe of labium straight-edged. [lividus]
4b. Median lobe of labium convex-edged. [5]


Note: The weakest aspect of this key is couplet 4, as it applies to Gomphus descriptus [Harpoon Clubtail], the difference in the “convexity” of the median lobe between lividus and descriptus being very slight and difficult to discern in practice. Donnelly (pers. comm.) has found that, at least with New York specimens, the posterior narrowing of the median lobe of the labium is more abrupt in livid, and relatively gradual in descriptus. Also, the labial teeth are better developed in livid than in descriptus. These characters are so relative that any unknown suspected of being either of these species should be compared to reference specimens.

Tech Tips

The following equipment was used to shoot Photo No. 2 and 3: Canon EOS 5D Mark II digital camera, in manual mode; Kenko 20mm macro automatic extension tubeCanon EF100mm f/2.8L Macro lens (set for manual focus); Canon MT-26EX-RT Macro Twin Lite set for “Master” mode, and Canon 580 EX- and Canon 580EX II Speedlites set for “Slave” mode. Photo No. 1, 4, and 5Canon MP-E 65mm Macro lens (manual focus only, set for either 2x or 3x magnification) plus the multiple-flash setup.

Photo No. 1-3 are focus-stacked composite images created and annotated using Adobe Photoshop CC 2017.

Bob Perkins’ photos were shot using a Canon EOS Rebel T3i camera body and Canon EF-S 60mm macro lens.

Copyright © 2018 Walter Sanford. All rights reserved.

Boyeria vinosa exuvia

March 8, 2018

Bob Perkins collected and reared an unknown species of odonate nymph from a stream located in southwestern Virginia. The larva emerged from one of Bob’s holding tanks on 08 May 2017 and metamorphosed into an adult female Fawn Darner dragonfly (Boyeria vinosa). Fawn Darner is a member of the Family Aeshnidae (Darners).

A two-step process was used to verify the genus and species of the exuvia.

  1. Determine the family.
  2. Determine the genus and species.

Step 1. Family

First, determine the family of the specimen. For reference, watch the excellent Vimeo video Identifying dragonfly larva to family (8:06). Here’s the decision tree used to identify the exuvia as a member of the Family Aeshnidae (Darners).

  • The specimen has a flat labium that doesn’t cover the face (not mask-like), as shown in Photo No. 1, 3, and 4.
  • Antennae are thin and thread-like (not club-like, as in Gomphidae larvae), as shown in Photo No. 1-4.
  • Eyes are large relative to the size of the head, as shown in Photo No. 1.

No. 1 | Boyeria vinosa | exuvia (face-head)

Step 2. Genus and species

The dichotomous key for Boyeria larvae that appears on p. 22 in Identification Keys to Northeastern Anisoptera Larvae, compiled by Ken Soltesz, was used to verify the genus and species of the exuvia.

1. Length when grown 37-39 mm;
Lateral spines on abdominal segments 4 to 9 (minute on 4);
Mentum of labium more than twice as long as its median width;
Inferior caudal appendages (paraprocts) stouter, scarcely incurved at tips;
Apex of superior anal appendage (epiproct) uncleft and sharply pointed;
Epiproct as long as paraprocts. [grafiana]

1’. Length when grown 34-37 mm;
Lateral spines on abdominal segments 5 to 9;
Mentum of labium less than twice as long as its median width;
Inferior caudal appendages (paraprocts) more slender, distinctly incurved at tips;
Apex of superior anal appendage (epiproct) deeply emarginate (cleft);
Epiproct distinctly shorter than paraprocts. [vinosa]

The exuvia is ~35 mm (~3.5 cm) long. Lateral spines are present on abdominal segments five to nine (S5 to S9).

No. 2 | Boyeria vinosa | exuvia (dorsal)

The rudimentary ovipositor shown in Photo No. 3 indicates this individual is a female.

No. 3 | Boyeria vinosa | exuvia (ventral)

The prementum is less than twice as long as its median width, as shown in Photo No. 4.

No. 4 | Boyeria vinosa | exuvia (prementum)

The paraprocts are incurved at the tips.

No. 5 | Boyeria vinosa | exuvia (anal pyramid)

There is a cleft in the apex of the epiproct. The cleft is closed in the exuvia (above); it is open in the nymph (below). Both photos show the same specimen, before and after emergence.

Image used with permission from Bob Perkins.

Both the Soltesz dichotomous key and the key for Boyeria larvae that appears on pp. 88-89 in Dragonflies of North America, Third Edition by Needham et al. describe the epiproct as “distinctly shorter than paraprocts.” The epiproct and paraprocts are nearly the same length. In the opinion of the author, this marker is least useful for differentiating grafiana and vinosa nymphs/evuviae.

This specimen is confirmed as an exuvia from a Fawn Darner dragonfly (Boyeria vinosa).

Adult

The adult Fawn Darner dragonfly emerged on 08 May 2017. Fawn Darners are, on average, 60-71 mm long (Paulson, 2011).

Image used with permission from Bob Perkins.

This individual is a female, as indicated by its rounded hind wings (above) and prominent ovipositor (below).

Image used with permission from Bob Perkins.

Tech Tips

The following equipment was used to shoot Photo No. 2 and 3: Canon EOS 5D Mark II digital camera, in manual mode; Kenko 20mm macro automatic extension tubeCanon EF100mm f/2.8L Macro lens (set for manual focus); and Canon MT-26EX-RT Macro Twin LitePhoto No. 1, 4, and 5: Canon EOS 5D Mark II digital camera, in manual mode; Canon MP-E 65mm Macro lens (manual focus only, set for 2x – 3x magnification); and Canon MT-26EX-RT Macro Twin Lite.

Sunpak LED-160 Video Light (with a white translucent plastic filter) was used for all photos.

Adobe Photoshop CC 2017 was used to annotate selected images.

Bob Perkins’ photos were shot using a Canon EOS Rebel T3i camera body and Canon EF-S 60mm macro lens. The photos of the adult were taken soon after emergence.

Related Resource

The dichotomous key for Boyeria larvae that appears on pp. 88-89 in Dragonflies of North America, Third Edition by Needham et al. is as follows.

1. Epiproct about as long as paraprocts, its apex acute, not emarginate; greatest width of prementum about 3/5 its length; paraprocts shorter than abdominal segments 9+10, each with apex nearly straight (Fig. 85). [grafiana]

1’. Epiproct distinctly shorter than paraprocts, its apex distinctly emarginate; greatest width of prementum about 2/3 its length; paraprocts longer than abdominal segments 9+10, each with apex distinctly incurved (Fig. 85). [vinosa]

Post Update

Thanks to Northeast Odonata Facebook group members Curt Oien and Nick Block for sharing the following helpful tips. Both Curt and Nick are also members of the Dragonfly Society of the Americas.

The face-head of an Aeshnidae nymph/exuvia is relatively easy to recognize. Would I have said that when I was a beginner? In a word, no. Watch the Vimeo video a few times and you’ll see what I’m saying.

So, after you determine a specimen is from the Family Aeshnidae, look for a prominent light-colored diamond shape on the dorsal side of abdominal segment eight (S8), as shown in Photo No. 2 and 5: if it’s there, then you can be fairly certain the genus is Boyeria.

Curt looks for the cleft in the epiproct to determine the species. I recommend looking at other markers that are easier to see.

Copyright © 2018 Walter Sanford. All rights reserved.

Erpetogomphus designatus exuvia

February 28, 2018

Michael Powell collected several odonate exuviae during a photowalk along the Potomac River in Fairfax County, Virginia USA, including two damselflies and two dragonflies. The exact date is uncertain, although Mike thinks the exuviae were collected sometime between 19-23 July 2017.

A two-step process was used to identify the genus and species of one of the two dragonfly exuviae.

  1. Determine the family.
  2. Determine the genus and species.

Step 1. Family

First, determine the family of the specimen. For reference, watch the excellent Vimeo video, Identifying dragonfly larva to family (8:06). Here’s the decision tree used to identify the exuvia as a member of the Family Gomphidae (Clubtails).

  • The specimen has a flat labium that doesn’t cover the face (not mask-like). [See Photo No. 4.]
  • Antennae are club-like (not thin and thread-like, as in Aeshnidae). [See Photo No. 1.]
  • Eyes not exceptionally large compared to the size of the head (not large, as in Aeshnidae). [See Photo No. 1.]
(See a full-size version of the original photo, without annotation.)

Step 2. Genus and species

The dichotomous key for Erpetogomphus larvae that appears on pp. 156-157 in Dragonflies of North America, Third Edition by Needham et al. was used to identify the genus and species of the exuvia. The first couplet [1, 1′] is as follows.

1. Dorsal hooks well-developed on abdominal segments 2-9 (Fig. 183a) [2]
1’. Dorsal hooks absent or vestigial on abdominal segments 7-9 (Fig. 183c) (usually present on at least some of the more anterior segments [3]

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

A leap of faith is required to see the small dorsal hooks present on abdominal segments two through nine (S2 – S9), but they are there.

Notice the divergent wing pads. The white filaments that extend from the split in the thorax (as shown above) are breathing tubes, artifacts of the unique respiratory system of dragonfly nymphs.

2(1). Lateral spines present on abdominal segments 6-9 only; femora with long, hair-like setae [designatus] [Eastern Ringtail]
2’. Lateral spines present on abdominal segments 5-9 only; femora without long, hair-like setae [constrictor] [Knob-tipped Ringtail]

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

The caudal appendages (terminal appendages) are all about the same length, a key marker for designatus.

Notice the flat labium that doesn’t cover the face, as shown in the following photo.

This specimen is tentatively identified as an exuvia from an Eastern Ringtail dragonfly (Erpetogomphus designatus). The exuvia that Mike Powell collected is similar in appearance to the following excellent photograph of an Erpetogomphus designatus nymph by Steve Krotzer, Haysop Hill Photography.

Image used with permission from Steve Krotzer.

Tech Tips

The following equipment was used to shoot Photo No. 2 and 4: Canon EOS 5D Mark II digital camera, in manual mode; Kenko 20mm macro automatic extension tubeCanon EF100mm f/2.8L Macro lens (set for manual focus); and Canon MT-26EX-RT Macro Twin LitePhoto No. 1 and 3: Canon EOS 5D Mark II digital camera, in manual mode; Canon MP-E 65mm Macro lens (manual focus only, set for 2x magnification); and Canon MT-26EX-RT Macro Twin Lite. A Sunpak LED-160 Video Light (with a white translucent plastic filter) was used for some photos.

Adobe Photoshop CC 2017 was used to annotate selected images.

Copyright © 2018 Walter Sanford. All rights reserved.

Black Saddlebags (terminal appendages)

September 15, 2017

Male and female Black Saddlebags dragonflies (Tramea lacerata) are somewhat similar in appearance. Terminal appendages can be used to identify gender.

Female

A female Black Saddlebags was spotted along Deephole Point Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

10 SEP 2017 | Occoquan Bay NWR | Black Saddlebags (female)

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

10 SEP 2017 | Occoquan Bay NWR | Black Saddlebags (female)

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

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 male Black Saddlebags was spotted in the central wetland area at Huntley Meadows Park, Fairfax County, Virginia USA.

12 SEP 2014 | Huntley Meadows Park | Black Saddlebags (male)

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

Copyright © 2017 Walter Sanford. All rights reserved.

Fine-lined Emerald dragonflies (males)

September 13, 2017

Three Fine-lined Emerald dragonflies (Somatochlora filosa) were spotted during a long photowalk at Occoquan Bay National Wildlife Refuge. All three individuals are males, as indicated by their terminal appendages and prominent hamules.

If I have seen further it is by standing on the shoulders of giants. Source Credit: Sir Isaac Newton.

Sincere thanks to Jim Waggener, Wildlife Survey Coordinator for The Audubon Society of Northern Virginia, as well as other members of Jim’s survey group for sharing information that enabled me to find this rare to uncommon species of dragonfly. The group has surveyed four sites in Northern Virginia regularly for many years, including Occoquan Bay National Wildlife Refuge.

No. 1

Fine-lined Emerald dragonflies seem to prefer perching on bare tree branches or long stems of wild grass, typically at chest- or head-height although not exclusively. For example, this guy was perched about waist-high on a cluster of fallen tree branches.

10 SEP 2017 | Occoquan Bay NWR | Fine-lined Emerald (male)

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

Fine-lined Emerald seems to prefer perching in sun rather than shade, unlike Mocha Emerald (Somatochlora linearis) — another species from the Family Corduliidae (Emeralds) found in Northern Virginia that prefers shady places.

The following ventral-lateral shot shows the lines on the thorax for which this species is named.

10 SEP 2017 | Occoquan Bay NWR | Fine-lined Emerald (male)

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

No. 2

The male shown in the next photo is perched on a long grass stem, about chest-high. He posed for two shots, patrolled back-and-forth a few times, and then disappeared.

10 SEP 2017 | Occoquan Bay NWR | Fine-lined Emerald (male)

No. 3

The last male was the most cooperative model. The first photo was taken at a distance of approximately six feet.

10 SEP 2017 | Occoquan Bay NWR | Fine-lined Emerald (male)

The next photo was taken a step-or-so closer…

10 SEP 2017 | Occoquan Bay NWR | Fine-lined Emerald (male)

And after a few side steps, I was able to take a good lateral shot.

10 SEP 2017 | Occoquan Bay NWR | Fine-lined Emerald (male)

The Backstory

This might be one of those stories in which the take-away is “persistence pays dividends.”

I made two trips to Occoquan Bay NWR during Fall 2016 when Fine-lined Emerald was my target species. On 21 September 2016, I spotted one or more dragonflies (species unknown) patrolling the treetops along one of the trails at OBNWR. I didn’t see any signs of Fine-lined Emerald on 25 October 2016, consistent with records for late-date maintained by Kevin Munroe (04 October for Northern Virginia) and Dr. Steven Roble (15 October for the Commonwealth of Virginia).

In retrospect, I realized I started searching too late in the year during 2016 so I started earlier in 2017. My first trip to OBNWR was on 30 August 2017; it turned out to be fruitless. I hit the jackpot on 10 September 2017! Fine-lined Emerald is a new species for my life list of dragonflies.

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. 2006-2017. OdonataCentral: An online resource for the distribution and identification of Odonata. Available at http://www.odonatacentral.org. (Accessed: September 14, 2017).

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

Related Resources

Copyright © 2017 Walter Sanford. All rights reserved.

Springtime Darner (terminal appendages)

September 11, 2017

Male and female Springtime Darner dragonflies (Basiaeschna janata) are colored similarly sometimes. Terminal appendages can be used to identify gender.

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 male Springtime Darner was spotted along a mid-size rocky stream located at Hemlock Overlook Regional Park (HORP), Fairfax County, Virginia USA.

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

Female

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

Female Springtime Darners are polymorphic: the spots on their abdomen are either blue (andromorphic) or green (heteromorphic); this female — spotted at a remote location in Huntley Meadows Park (HMP) — is a blue andromorph.

15 APR 2016 | HMP | Springtime Darner (female, blue andromorph)

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

Copyright © 2017 Walter Sanford. All rights reserved.

Russet-tipped Clubtail (terminal appendages)

August 14, 2017

Male Russet-tipped Clubtail dragonflies (Stylurus plagiatus) have a larger, more colorful club than females of the same species, their hind wings are “indented,” and their terminal appendages are shaped differently. Compare and contrast the appearance of males and females by looking at the following annotated images.

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”).

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

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

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

Female

All female dragonflies have a pair of cerci (superior appendages) that have little or no function. The hind wings of female clubtails are rounded.

21 AUG 2015 | Powhatan County, VA | Russet-tipped Clubtail (female)

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

The female Russet-tipped Clubtail dragonfly shown in the preceding image was spotted along the James River by my good friend Michael Boatwright, founder of the Virginia Odonata Facebook group. Sincere thanks to Mike for permission to use his photographs (background and inset).

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 © 2017 Walter Sanford. All rights reserved.

“Big Boy”

July 19, 2017

Several Eastern Ringtail dragonflies (Erpetogomphus designatus) were spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. These individuals are male, as indicated by their terminal appendages and “indented” hind wings.

All of the photos in this set were taken using my Fujifilm X-T1 digital camera, Fujinon 100-400mm telephoto zoom lens, and Fujifilm EF-X500 shoe mount flash.

I nicknamed the Fujinon 100-400mm lens “Big Boy” because it’s so big and heavy. I use a Sunpak 6700M monopod and Vanguard SBH 100 ball head to support the lens.

Zoom in on the full-size version of the preceding photo. Notice the terminal appendages are spread apart, revealing a clear look at both the cerci and hook-shaped epiproct.

Related Resource: You complete me – a blog post published on 19 February 2016 in which I shared my first impressions of the Fujinon 100-400mm telephoto zoom lens.

Copyright © 2017 Walter Sanford. All rights reserved.

Mocha Emerald dragonfly claspers

July 13, 2017

Mocha Emerald dragonfly (Somatochlora linearis) was spotted along a small creek at a remote location in the forest at Huntley Meadows Park. This individual is a male, as indicated by his terminal appendages and hamules.

All 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”).

09 JUL 2017 | Huntley Meadows Park | Mocha Emerald (male)

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

09 JUL 2017 | Huntley Meadows Park | Mocha Emerald (male)

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

Male dragonfly secondary genitalia, called hamules, are located below abdominal segments two and three (S2 and S3), as shown in the following annotated image. Hamules come in a variety of sizes and shapes, but their function is identical for all species of odonates.

hamules: paired structures that project from genital pocket under second segment and hold female abdomen in place during copulation Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 11618-116198). Princeton University Press. Kindle Edition.

09 JUL 2017 | Huntley Meadows Park | Mocha Emerald (male)

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

Related Resource: Mocha Emerald terminal appendages (female).

Technique Hint: Did you notice that the “focus” of each photo (not to be confused with the focus point) is shown against a lighter background? That’s no accident — I composed each shot that way. As a result, the terminal appendages (cerci and epiproct) are much easier to see in the first two photos than the last shot, in which the composition highlights the hamules.

Copyright © 2017 Walter Sanford. All rights reserved.


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