Posts Tagged ‘hamules’

Blue-fronted Dancer damselfly

August 31, 2020

A Blue-fronted Dancer damselfly (Argia apicalis) was spotted during a photowalk with Michael Powell near Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR), Fairfax County, Virginia USA.

A. apicalis has “a blue form female and a brown form female.” Since neither the hamules nor terminal appendages can be seen clearly in the preceding photo, I’m unsure whether this individual is male or female.

Post Update

Michael Ready, good friend and fellow member of the Dragonfly Society of the Americas, shared the following comment via e-mail.

That’s an outstanding picture of a Blue-fronted Dancer. You state you are unsure of the individual’s gender. I am confident that it is a male. According to my field guides (Lam and Paulson), the blue-form female lacks the blue eyes and blue S8-10 that are apparent in your picture. Source Credit: Michael Ready.

Thanks for the kind words and helpful information, Michael! As it turns out, the field marks that you described are shown clearly in one of my blog posts: Blue-fronted Dancers (male, female), especially this photo.

Copyright © 2020 Walter Sanford. All rights reserved.

Acceptable uncertainty

July 27, 2020

A teneral damselfly was spotted by Michael Powell during a photowalk with me along a mid-size stream in Fairfax County, Virginia USA.

teneral: adult after it has just emerged, soft and not definitively colored. Source Credit: Glossary [of] Some Dragonfly Terms, by Dennis Paulson.

Teneral odonates, especially females, can be challenging at best to identify with certainty. And so it is with this one.

The first photo is the record shot. (Get a shot, any shot.) I think I might have just missed focus on the face.

No. 1 | 15 JUL 2020 | Fairfax County, VA | teneral damselfly

Refine the shot.

No. 2 | 15 JUL 2020 | Fairfax County, VA | teneral damselfly

Although this individual is definitely a member of Family Coenagrionidae (Narrow-winged Damselflies), both the genus/species and gender are somewhat uncertain.

It appears to be an Argia sp. based on long tibial spines. I think it is a male. Source Credit: Mike Boatwright, founder and administrator of the Virginia Odonata Facebook group.

For what it’s worth, Mike Powell and I saw three species of damselflies during our outing: Blue-tipped Dancer (Argia tibialis); Dusky Dancer (Argia translata); and Powdered Dancer (Argia moesta).

I’m not sure of the gender. I see what might be hamules, indicating this individual is male, but also see what looks like a female stylus (plural: styli) near the tip of the abdomen, indicating this might be a female.

Bonus Bugs and More

Look closely at Photo No. 1, the “record shot.” Notice the small orange colored insect perched along the bottom of the same rock on which the damselfly is perched. Can anyone identify Bonus Bug No. 1?

Post Update: “The fly at the [bottom] of this photo may be a black fly (Simuliidae).” Source Credit: John Smith, member “BugGuide” Facebook group.

Now look at Photo No. 2. Notice there is some type of dark insect that’s perched along the same edge of the rock as the damselfly. Can anyone identify Bonus Bug No. 2?

Post Update: “The bug at the bottom of your photo appears to be a caddisfly.” Source Credit: John Smith, member “BugGuide” Facebook group.

Also notice the dark insect is perched near what might be the exuvia from which the damselfly emerged, as shown in Photo No. 2. It’s tannish in coloration.

I didn’t see either the bonus bugs or possible exuvia when we were in the field. Of course!

Related Resource: Newly emerged damselflies, a companion blog post by Michael Powell.

Copyright © 2020 Walter Sanford. All rights reserved.

Spotlight on Slaty Skimmer

July 22, 2020

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.

American Rubyspot damselfly (male)

June 24, 2020

During a photowalk with Michael Powell in Fairfax County, Virginia USA, Mike spotted an American Rubyspot damselfly (Hetaerina americana) perched facing the Potomac River. This individual is a male, as indicated by his red coloration, hamules, and terminal appendages.

All of the photos in the following gallery look similar, although there are subtle differences.

The first photo is the “record shot” for this individual, that is, “get a shot, any shot.” Actually, this one turned out to be a good photo! The camera was set for an aperture of f/5.6 for all shots in the gallery. This viewing angle provided the clearest look at his terminal appendages given the relatively shallow depth-of-field.

08 JUN 2020 | Fairfax County, VA | American Rubyspot (male)

The next photo shows a better look at the damselfly’s metallic ruby red face. Handsome!

08 JUN 2020 | Fairfax County, VA | American Rubyspot (male)

Finally, I just like the look of the “light” in the last photo. Dark and moody.

08 JUN 2020 | Fairfax County, VA | American Rubyspot (male)

Related Resource: American Rubyspot – a blog post by Michael Powell

Copyright © 2020 Walter Sanford. All rights reserved.

Calico Pennant dragonfly (male)

September 6, 2019

There’s a feeling I get
When I look to the west
And my spirit is crying for leaving.

A Calico Pennant dragonfly (Celithemis elisa) was observed during a photowalk with Michael Powell at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

This individual is a mature male, as indicated by his red coloration, the secondary genitalia (hamules) located on the underside of abdominal segments two-three (2-3), and terminal appendages.

Copyright © 2019 Walter Sanford. All rights reserved.

Fawn Darner dragonfly (male)

August 26, 2019

A Fawn Darner dragonfly (Boyeria vinosa) was spotted, netted, and released unharmed along the Little Patuxent River in the North Tract of Patuxent Research Refuge, Anne Arundel County, Maryland USA.

02 SEP 2012 | Patuxent Research Refuge | Fawn Darner (male)

This individual is a male, as indicated by the secondary genitalia (hamules) located on the underside of abdominal segments two-three (2-3).

02 SEP 2012 | Patuxent Research Refuge | Fawn Darner (male)

Thanks to Louisa Craven, my good friend and photowalking buddy, for holding the specimen in the first two photos while I used her Apple iPhone 4S to take photos. This was our first “stream walk” in search of dragonflies and damselflies and both of us were afraid to carry our camera gear as we waded in the river.

02 SEP 2012 | Patuxent Research Refuge | Fawn Darner (male)

The Backstory

I posted these photos in my Project Noah Nature Journal two days after an Audubon Naturalist Society field trip to the North Tract of the Patuxent Research Refuge, led by Richard Orr, renowned expert on odonates of the mid-Atlantic region of the United States.

Some of the photos from the Project Noah “spotting” were added to my photoblog in order to backfill my Life List of Odonates to include a record of an adult Fawn Darner.

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

Brown Spiketail dragonflies

May 6, 2019

Several Brown Spiketail dragonflies (Cordulegaster bilineata) were spotted during a photowalk with my good friend Mike Powell at Occoquan Regional Park, Fairfax County, Virginia USA.

Male

The first individual is a male, as indicated by his “indented” hind wings, and terminal appendages. Notice the epiproct for Brown Spiketail is a wide “plate” that spans both cerci, as shown in the full-size version of the following photo.

The next individual is also male, as indicated by his hamules, located below abdominal segments two and three (S2 and S3).

Female

The last individual is a female, as indicated by her rounded hind wings and terminal appendages.

Credits

Thanks to Michael Boatwright, founder and administrator of the Virginia Odonata Facebook group, for confirming my tentative identification of the gender of the first and last individuals.

Phenology

Phenology (noun) is defined as “the study of cyclic and seasonal natural phenomena, especially in relation to climate and plant and animal life.”

There is an annual cycle of odonate activity that can be subdivided into three broad categories: Early Season (spring); Mid-season (summer); and Late Season (fall).

Brown Spiketail is an “Early Season” species for locations in the Commonwealth of Virginia. I have noticed that the adult flight period for a given species of odonate in Northern Virginia tends to lag behind Amherst County, where my good friend Mike Boatwright (Mike B) lives, by about one-to-two weeks. When Mike B reported his first sighting of Brown Spiketail on 24 April in Amherst County, I knew it wouldn’t be long until Brown Spiketail would be flying in Fairfax County. Eight (8) days later, Mike Powell and I spotted our first-of-season Brown Spiketail dragonflies. Thanks for the heads-up, Mike B!

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

Test shots: Stylogomphus albistylus exuvia

December 19, 2018

Bob Perkins collected and reared an Eastern Least Clubtail dragonfly (Stylogomphus albistylus) nymph. This blog post features two focus-stacked composite images of the exuvia from the odonate nymph.

Nine photos were used to create the first focus stack. This small specimen features several easy-to-recognize field marks including large, dish-shaped antennae, distinctive color bands on the legs, lateral spines on abdominal segments eight and nine (S8-9), and terminal appendages tipped with a lighter color.

12 photos were used to create the last focus stack. This individual might be a male, as indicated by what appear to be vestigial hamules on the ventral side of the specimen.

Tech Tips

The following equipment was used to shoot all of the photographs for the two focus-stacked composite images, shown above: 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 Lite set for “Master” mode, and several external flashes set for “Slave” mode including Canon 580 EX- and Canon 580EX II Speedlites and a Godox TT685C Thinklite TTL Flash fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.

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

Copyright © 2018 Walter Sanford. All rights reserved.

Macromia alleghaniensis exuvia

October 6, 2018

Michael Boatwright, founder and administrator of the Virginia Odonata Facebook group, collected an odonate exuvia on 07 June 2018 along either Little Otter Creek or Otter Creek near the place where both creeks are distributaries of Otter Lake in Amherst County, Virginia USA.

A two-step process was used to identify 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 Macromiidae (Cruisers).

  • The specimen has a mask-like labium (prementum) that covers the face, as shown in Photo No. 1, characteristic of four families of odonates: Cordulegastridae (Spiketails); Corduliidae (Emeralds); Libellulidae (Skimmers); and Macromiidae (Cruisers).
  • The teeth on the margins of the labium have a regular pattern. (The pattern reminds me of a “spork.”)
  • Its eyes are small, wide set, and stick up.
  • Image No. 2 shows there is a horn on the face-head, characteristic of Macromiidae.

Photo No. 1 shows a face-head view of the exuvia, magnified approximately three times life size (~3x).

No. 1 | Macromia alleghaniensis | exuvia (face-head)

Image No. 2 shows the top of the head of the exuvia, magnified approximately three times life size (~3x). Notice the prominent horn on the face.

No. 2 | Macromia alleghaniensis | exuvia (head-horn)

Step 2. Genus and species

Two dichotomous keys found on p. 27 of Identification Keys to Northeastern Anisoptera Larvae, compiled by Ken Soltesz, were used to determine the genus and species of the exuvia. Field marks that match this specimen are highlighted in boldface green text. Three boldface green asterisks (***) are used to highlight the thread for identification of this specimen.

Key to the Genera of the Family Macromiidae

***1b. Lateral spines of abdominal segment 9 do not reach to rearward level of tips of inferior appendages [paraprocts]; Sides of head somewhat convergent behind eyes to pair of low turbercules on hind angles; Lateral setae of labium = 6; Small dorsal hook on segment 10. [Macromia]

A small dorsal hook on abdominal segment 10 is characteristic of Genus Macromia.

No. 3 | Macromia alleghaniensis | exuvia (dorsal-lateral)

Look closely at the full-size version of Image No. 4. Notice the little “nub” on abdominal segment 10 (S10), below the underside of the dorsal hook on abdominal segment nine (S9). The same structure is labeled with a white question mark in Image No. 3.

No. 4 | Macromia alleghaniensis | exuvia (dorsal-lateral)

The lateral spines of abdominal segment 9 (S9) do not reach rearward to the tips of the inferior appendages (paraprocts).

No. 5 | Macromia alleghaniensis | exuvia (dorsal)

Key to the Species of Macromia

1a. Lateral spines of abdominal segments 8 and 9 directed straight to rearward. [illinoiensis]

***1b. Lateral spines of abdominal segments 8 and 9 incurved, especially 8. [alleghaniensis]

The lateral spines of abdominal segments 8 and 9 (S8-9) are incurved, especially segment 8 (S8), indicating this species is alleghaniensis.

No. 6 | Macromia alleghaniensis | exuvia (ventral)

This individual is probably a male, as indicated by what appear to be vestigial hamules located on the ventral side of abdominal segments two and three (S2-3).

Summary

A prominent horn on the face is a key field mark for the Family Macromiidae (Cruisers), a small dorsal hook on abdominal segment 10 is one characteristic of the Genus Macromia, and the lateral spines of abdominal segments 8 and 9 (S8-9) are incurved, indicating the species is alleghaniensis. Therefore this specimen is an Allegheny River Cruiser dragonfly (Macromia alleghaniensis).

Bonus Gallery

No. 7 | Macromia alleghaniensis | exuvia (face-head)

No. 8 | Macromia alleghaniensis | exuvia (dorsal-lateral)

No. 9 | Macromia alleghaniensis | exuvia (dorsal)

Related Resources

Tech Tips

The following equipment was used to shoot Photo/Image No. 3-9: 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/Image No. 1 and 2Canon MP-E 65mm Macro lens (manual focus only, set for ~3x magnification) plus the multiple-flash setup.

Image No. 2-8 are focus-stacked composite images created and annotated using Adobe Photoshop CC 2017: Image No. 2 (eight photos); Image No. 3 (six photos); Image No. 4 (four photos); Image No. 5 (five photos); Image No. 6 (five photos); Image No. 7 (seven photos); Image No. 8 (seven photos).

Copyright © 2018 Walter Sanford. All rights reserved.

“Bender” on grass

June 22, 2018

Gray Petaltail dragonfly (Tachopteryx thoreyi) is well-known for its tendency to perch on gray and tan colored surfaces, including tree trunks. Less well-known is the fact that Gray Petaltail perches wherever it wants, including tall grasses growing in the forest seeps from which the species emerges.

“Bender,” my nickname for a male Gray Petaltail with a malformed abdomen, is shown perched on grass stems in the following photo set.

No. 1 | 06 JUN 2018 | Northern Virginia | Gray Petaltail (male)

The next photo provides a good view of the gentle curve in Bender’s abdomen, as well as his hamules, visible on the ventral side of abdominal segments two and three (S2 and S3).

No. 2 | 06 JUN 2018 | Northern Virginia | Gray Petaltail (male)

Like many male odonates, Bender probably perched on the grass in order to make himself available for hook-ups with females of the same species.

No. 3 | 06 JUN 2018 | Northern Virginia | Gray Petaltail (male)

Bender aggressively defended the prominent perch against other odonates that intruded upon his territory.

No. 4 | 06 JUN 2018 | Northern Virginia | Gray Petaltail (male)

No flash/flash

Compare/contrast Photo No. 3-4. The batteries in my external flash unit were almost drained completely by the time I shot the photos. As a result, the flash worked sometimes and didn’t work other times. I’m fairly certain the flash didn’t fire for the Photo No. 3, and equally certain it fired for Photo No. 4. Some photographers might contend the no-flash photo is “arty”; I contend Photo No. 4 — the fill-flash version — has better color balance, color saturation, and more detail in the shadows.

Copyright © 2018 Walter Sanford. All rights reserved.


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