Posts Tagged ‘female’

Swift River Cruiser exuvia (face-head)

November 20, 2020

The following image is a focus-stacked composite of three photos, focused on the left eye, right eye, and both eyes respectively.

27 May 2017 | Riverbend Park | Swift River Cruiser (exuvia, face-head)

Tech Tips

The dragonfly exuvia was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique.

Several photos were taken using my Canon EOS 5D Mark II digital camera, a Kenko 12mm extension tube, and Laowa 25mm Ultra Macro Lens, set for f/4.0 (the sweet spot for this lens) at ~3.0x magnification.

Godox TT685C external flash was used to backlight the background (a piece of translucent white plastic) and a Godox TT685F external flash was used as a key light on the right side of the subject. The flash was triggered wirelessly by a Godox X2TC.

Check the EXIF/IPTC info for the photograph for complete details regarding photo gear and camera settings.

Adobe Photoshop CC 2017 was used to create a focus-stacked composite image that was edited using Apple Aperture.

The Backstory

Swift River Cruiser dragonfly (Macromia illinoiensisexuvia was collected on 27 May 2017 along the Potomac River at Riverbend Park in Fairfax County, Virginia USA. This individual is a female.

Copyright © 2020 Walter Sanford. All rights reserved.

“It ain’t over till it’s over.”

November 2, 2020

“It ain’t over till it’s over” is a phrase commonly associated with baseball player/coach/manager Yogi Berra. In this case, “it” refers to odonate season and it’s not over in Northern Virginia till Autumn Meadowhawk dragonflies (Sympetrum vicinum) disappear. Clearly, it ain’t over although “the end is near.”

This individual is a female, as indicated by her red/tan coloration and terminal appendages.

It ain’t over till the fat lady sings” is a similar saying that is often attributed to Yogi Berra mistakenly. “The fat lady” refers to the fact that many female dragonflies, such as Autumn Meadowhawk, have a wider body than males of the same species.

Look closely at the full-size version of the preceding photo. Notice what appears to be an egg mass located on the underside of her body, near the tip of the abdomen.

Copyright © 2020 Walter Sanford. All rights reserved.

Damselfly (species unknown)

October 28, 2020

A damselfly was spotted near a small pool of water in the forest at Huntley Meadows Park.

14 OCT 2020 | Huntley Meadows Park | damselfly (species unknown)

This individual is definitely a member of Family Coenagrionidae (Narrow-winged Damselflies), possibly a female Familiar Bluet (Enallagma civile).

Sidebar: Scientific Classification of Damselflies

The following concise explanation of the scientific classification of damselflies is provided to help the reader understand where the genus Enallagma (American Bluets) fits into the bigger picture of the Order OdonataSuborder Zygoptera (Damselflies).

There are four families of damselflies in the United States of America (USA), although only three families occur in the mid-Atlantic USA: Broad-winged damselflies; Narrow-winged damselflies (a.k.a., Pond Damselflies); and Spreadwing damselflies.

  1. Family Calopterygidae – Broad-winged Damselflies
  2. Family Coenagrionidae – Narrow-winged Damselflies
  3. Family Lestidae – Spreadwings

Note: Family Platystictidae (Shadowdamsels) is the fourth family of damselflies in the USA. Desert Shadowdamsel (Palaemnema domina) is the only member of this family. P. domina is rare, known to occur only in Arizona in the southwestern United States.

1. Family Calopterygidae is comprised of two genera.

2. Family Coenagrionidae is comprised of 14 genera. Three genera are common in Northern Virginia: Argia (Dancers); Enallagma (American Bluets); and Ischnura (Forktails).

3. Family Lestidae is comprised of two genera.

  • Archilestes (e.g., Great Spreadwing)
  • Lestes (e.g., Slender Spreadwing, Southern Spreadwing, Swamp Spreadwing)

There are relatively few genera of Broad-winged Damselflies and Spreadwing Damselflies. In contrast, there are many more genera and species of Narrow-winged Damselflies — more species, including many that look similar, makes this family the most challenging to learn!

Related Resource: “The Odonata of North America” is a complete list of both scientific names and common names for damselflies and dragonflies, maintained by the Dragonfly Society of the Americas.

An interactive version of the same species list is available from the Odonata Central Web site. The master list can be filtered in many ways. Location is perhaps the most useful filter.

For example, my good friend Mike Boatwright lives in Amherst County, Virginia USA. Click on the blue button labeled “Filter Results.” Then click the down arrow in the Location field, enter “Amherst” and select the complete location name that appears in a list of available options; click the “Apply Filtering” button. You should see a list of 97 species of odonates reported to occur in Amherst County, including 10 species in the genus Enallagma. Notice that Familiar Bluet is on the list, as well as several species of Enallagma that aren’t found where I live in Fairfax County, Virginia USA.

Copyright © 2020 Walter Sanford. All rights reserved.

HMK at HMP

October 26, 2020

14 OCT 2020 | HMP | Handsome Meadow Katydid (female)

The preceding photograph shows a female Handsome Meadow Katydid (Orchelimum pulchellum) perched on the boardwalk that goes through the central wetland area at Huntley Meadows Park (HMP), Fairfax County, Virginia USA.

Blue eyes are a good field mark for identifying Handsome Meadow Katydids. Notice the long, curved, reddish, scimitar-shaped structure extending from the posterior end of the abdomen. It’s an ovipositor that female katydids …

… use to insert eggs into hiding places … which can be in crevices on plants or even inside plant tissues [endophytic oviposition]. Source Credit: Matt Pelikan, BugGuide group on Facebook.

I like the way the reddish-pink American tearthumb (Persicaria sagittata) flowers in the background complement the color palette of the katydid.

Copyright © 2020 Walter Sanford. All rights reserved.

Slender Spreadwing damselfly (female)

October 16, 2020

Michael Powell spotted a Slender Spreadwing damselfly (Lestes rectangularis) perched on greenbriar vine in a wetland area alongside the gravel trail we were following out of Huntley Meadows Park, located in Fairfax County, Virginia USA.

This individual is a female, as indicated by her coloration and terminal appendages. Notice the tip of her abdomen is enlarged because of her reproductive anatomy, including an ovipositor.

Female Slender Spreadwing can be confused with female Southern Spreadwing damselflies. Several key field marks are used to differentiate the two species.

Blue shoulder stripes, slender abdomen, the ratio of abdominal segments seven and nine (S7 and S9), and whitish wing tips all point to Slender Spreadwing. S7 is more than twice the length of S9 in Slender, covered in Ed Lam’s book. Source Credit: Dr. Michael Moore, a professor (retired) 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.

Related Resource: Damselflies of the Northeast, by Ed Lam (author and illustrator).

Copyright © 2020 Walter Sanford. All rights reserved.

When is close too close?

October 14, 2020

Swift River Cruiser dragonfly (Macromia illinoiensisexuvia was collected on 27 May 2017 along the Potomac River at Riverbend Park in Fairfax County, Virginia USA. This individual is a female. The prominent horn on the head — a key field mark for exuviae from Family Macromiidae (Cruisers) — is noticeable in the following photo, although maybe not recognizable.

This photo is one of several test shots using “The Macroscope,” my nickname for the Laowa 25mm Ultra Macro Lens. The Laowa lens was mounted on my Canon 5D Mark II digital camera with a 12mm Kenko extension tube between the lens and camera body.

My new Laowa LED Ring Light was mounted on the front of the lens, powered by an Anker PowerCore+ 26800 PD 45W battery. The Laowa LED Ring Light was used to light the subject. A Sunpak LED-160 Video Light was used as a focusing aid. A Godox TT685C external flash was used to backlight a translucent white plastic background, using the “Meet Your Neighbours” technique. The flash was triggered wirelessly by a Godox X2TC.

The image is full-frame (5616 by 3744 pixels), that is, uncropped. The lens was set for f/4 (the “sweet spot” for the lens) at 4x magification. The camera was set for single point focus and spot metering, centered on the right eye of the exuvia.

Look closely at a full-size version of the image. At this magnification, the depth of field is very shallow: remnant ommatidia are clearly in focus; most of the image is out of focus.

In order to provide some context for what is shown in the first photo, the last photo shows the entire specimen. The photo gear used to take the shot is specified in a previous blog post.

When is close too close?

Close is too close when most of the subject is unrecognizable. At 4x magnification, it’s essential to use focus stacking to create a composite image.

The bigger take-away from this test shot is the Laowa LED Ring Light seems to work fairly well, albeit a sample size of one.

Related Resources

Copyright © 2020 Walter Sanford. All rights reserved.

When flat isn’t.

October 5, 2020

An Eastern Pondhawk dragonfly (Erythemis simplicicollis) was spotted along Delta Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is a female, as indicated by her green coloration and white terminal appendages.

15 SEP 2020 | OBNWR | Eastern Pondhawk (female)

The preceding photo was shot at an aperture of f/6.3 — notice the depth of field is a little too shallow at that f/stop to show the entire length of the dragonfly’s body in focus because she is perched on a small rock with her head/thorax a little higher above the ground than the tip of her abdomen.

Copyright © 2020 Walter Sanford. All rights reserved.

Veiled ventral view

October 2, 2020

Several Black and Yellow Argiope (Argiope aurantia) spiders were spotted during a photowalk with Michael Powell at Occoquan Bay National Wildlife Refuge (OBNWR), Prince William County, Virginia USA.

15 SEP 2020 | OBNWR | Black and Yellow Argiope (female)

This individual is a female, as indicated by her size. The preceding photo shows a ventral view of the spider, slightly obscured by the thin veil of her web. Contrast this ventral view with a recent blog post featuring a photo of the dorsal view of another A. aurantia.

Related Resource: Arachtober, a Flickr group that’s sure to make your spider senses tingle!

Copyright © 2020 Walter Sanford. All rights reserved.

Eastern Pondhawk dragonfly (female)

September 18, 2020

An Eastern Pondhawk dragonfly (Erythemis simplicicollis) was spotted during a photowalk with Michael Powell along Deephole Point Road at Occoquan Bay National Wildlife Refuge (OBNWR).

This individual is a female, as indicated by her green coloration and white terminal appendages.

15 SEP 2020 | OBNWR | Eastern Pondhawk (female)

Look closely at the full-size version of the preceding photo. Notice the subgenital plate, a black upside-down “shark fin” located beneath abdominal segment eight.

Underneath Segment 8 there is either an ovipositor or a subgenital plate, depending upon the species [of dragonfly]. Both structures are for laying eggs and extend over Segment 9 and possibly beyond. Source Credit: Dragonflies of the North Woods, by Kurt Mead.

Remember that “Segment 8 and 9” refers to abdominal segments eight and nine (of 10), numbered from front-to-back.

Related Resource: Eastern Pondhawk dragonflies, a photo-illustrated guide to the identification of male- and female terminal appendages.

Copyright © 2020 Walter Sanford. All rights reserved.

Black and Yellow Argiope (female)

September 7, 2020

While we’re doing that spider thing, here’s one that is seen commonly during late-summer/early-fall.

18 AUG 2020 | JMAWR | Black and Yellow Argiope (female)

A Black and Yellow Argiope (Argiope aurantia) spider was spotted during a photowalk with Michael Powell around Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR) in Fairfax County, Virginia USA. This individual is a female, as indicated by her size.

Females can be almost two inches long, while the males tend to be much smaller, rarely reaching even 1/4 of an inch in size. … The females live less than a year, dying by the first frosts. The males usually die right after breeding. Source Credit: Golden Garden Spider, by Alonso Abugattas, a.k.a, the Capital Naturalist.

Copyright © 2020 Walter Sanford. All rights reserved.


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