Posts Tagged ‘oviposition’

Left on the cutting room floor

April 15, 2019

Close readers of my blog may have noticed I’ve posted a lot of photos recently that were taken years ago. Why were the photos passed over for publication closer to the time the shots were taken?

Sometimes there are better shots from the same photowalk that I’m eager to share, and sometimes they just don’t make the grade. The former requires no explanation; the following photos help to illustrate the latter.

The following female Slender Spreadwing damselfly (Lestes rectangularis) was spotted during a photowalk around a vernal pool in the forest at Huntley Meadows Park. The damselfly was perched in a hidey-hole in the vegetation at angle that made it impossible to get the entire subject in focus from head-to-tail.

The first photo shows the head and thorax in focus, but the tip of the abdomen and terminal appendages are out of focus.

15 SEP 2016 | HMP | Slender Spreadwing (female)

The last photo shows the tip of the abdomen and terminal appendages in focus, but the head and thorax are in soft focus. Look closely at a full-size version of the photo and you can see both styli (sing. stylus), structures that serve as sensors (like “curb feelers“) in egg positioning during oviposition.

15 SEP 2016 | HMP | Slender Spreadwing (female)

The odd thing is the focus point is nearly the same in both photos, and the aperture is identical. Go figure! Anyway, less than ideal focus is something that will cause me to reject photos every time. And then there’s that “too hot” blade of grass in the lower-right corner — talk about distracting!

Copyright © 2019 Walter Sanford. All rights reserved.

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Mosquito Hawks

July 26, 2018

I’m honored to announce several of my dragonfly photographs are featured on new signage at Melvin L. Newman Wetlands Center, Clayton County, Georgia. The info-graphic, entitled “Mosquito Hawks,” was created by Danielle Bunch, Senior Conservationist for Clayton County Water Authority.

Image used with permission from Danielle Bunch.

As a retired K-12 science educator, I know from first-hand experience that informal learning opportunities can be as valuable as formal education in school classrooms. I was glad to contribute several of my photographs of Common Green Darner dragonflies (Anax junius) to the new info-graphic for the wetland area. It’s flattering to share the stage with Giff Beaton, author of Dragonflies and Damselflies of Georgia and the Southeast.

Full-size versions of my photographs (featured on the signage) appear in several previous posts on my photoblog.

Related Resources

Copyright © 2018 Walter Sanford. All rights reserved.

Seamless transition

May 27, 2018

A seamless transition from the spring species of odonates to the summer species is slowly but surely underway.

Spangled Skimmer (Libellula cyanea) is a summer species that starts to appear in Northern Virginia in late spring. The following individual — spotted at Hidden Pond during a photowalk at Meadowood Recreation Area (MRA), Fairfax County, Virginia USA — is a teneral female, as indicated by her tenuous wings and terminal appendages.

21 MAY 2018 | MRA | Spangled Skimmer (teneral female)

Female Spangled Skimmers have a pair of flanges beneath their eighth abdominal segment that are used to scoop and hold a few drops of water when laying eggs (oviposition), hence the family name “Skimmer.” Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.

Copyright © 2018 Walter Sanford. All rights reserved.

Great Spreadwing (practice oviposition)

October 15, 2017

This gallery — named “practice oviposition” (egg-laying) — features a six-photo time series of a female Great Spreadwing damselfly (Archilestes grandis).

Female Great Spreadwing damselflies, like all female odonates, have two cerci (sing. cercus), superior appendages that have little or no function. Also notice two styli (sing. stylus), structures that serve as sensors (like “curb feelers“) in egg positioning during oviposition.

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

The female uses her styli to guide the ovipositor into position, as shown in the next two photos.

In this case, I saw no evidence that the ovipositor actually penetrated the tree twig. I think this was a practice run in preparation for the real thing, as the title of this blog post says.

Copyright © 2017 Walter Sanford. All rights reserved.

Great Spreadwing damselfly (female)

October 13, 2017

A Great Spreadwing damselfly (Archilestes grandis) was spotted near a vernal pool at a remote location in Huntley Meadows Park, Fairfax County, Virginia USA.

This individual is a female, as indicated by her terminal appendages and external reproductive anatomy, including two styli and an ovipositor.

Sometimes I struggle to choose between two similar images, so I decided to post both photos.

The following photo captured the “feel” of the morning light especially well.

The next two photos are among my favorites in this set.

This female was a more cooperative model after she moved to a perch on a man-made brush pile that provides habitat and shelter for many types of animals.

Female Great Spreadwing damselflies, like all female odonates, have two cerci (sing. cercus), superior appendages that have little or no function. Also notice two styli (sing. stylus), structures that serve as sensors (like “curb feelers“) in egg positioning during oviposition.

My next blog post will feature a six-photo time series that I named “practice oviposition” (egg-laying).

Copyright © 2017 Walter Sanford. All rights reserved.

Mocha Emerald terminal appendages (female)

September 29, 2017

Mocha Emerald dragonfly (Somatochlora linearis) was spotted by Andrew Rapp in Henrico County, Virginia USA. This individual is a female.

Terminal appendages

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

21 JUL 2017 | Henrico County, VA | Mocha Emerald (female)

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

21 JUL 2017 | Henrico County, VA | Mocha Emerald (female)

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

Notice the subgenital plate shown in the preceding photo.

subgenital plate: plate below S8 that holds bunches of eggs when enlarged; variable enough in shape to be of value in identification. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 11723-11724). Princeton University Press. Kindle Edition.

“S8” refers to abdominal segment eight. Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.

Oviposition (egg-laying)

The following Apple iPhone 3GS “raw” video clip shows a female Mocha Emerald dragonfly laying eggs by the process of oviposition. The process typically lasts a few seconds to a few minutes. This individual was spotted on 16 July 2011 during a photowalk through the “Wildlife Sanctuary,” one of seven small parks in the community of Hollin Hills, Fairfax County, Virginia USA.

Mocha Emerald dragonfly (female, ovipositing) [Ver. 2] (0:23)

Related Resource: Mocha Emerald terminal appendages (male).

Editor’s Note: Sincere thanks to Andrew Rapp for permission to use his still photographs.

Copyright © 2017 Walter Sanford. All rights reserved.

Great Blue Skimmer (mature females)

September 27, 2017

Two Great Blue Skimmer dragonflies (Libellula vibrans) were photographed during photowalks at Occoquan Bay National Wildlife Refuge (OBNWR), Prince William County, Virginia USA.

Both individuals are mature female, as indicated by their terminal appendages, muted coloration, and tattered wings. They were perching in shady hidey-holes relatively far from water.

Female Great Blue Skimmers have a pair of flanges beneath their eighth abdominal segment that are used to scoop and hold a few drops of water when laying eggs (oviposition), hence the family name “Skimmer.” Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.

Copyright © 2017 Walter Sanford. All rights reserved.

Aging gracefully, revisited

August 28, 2017

Great Blue Skimmer dragonfly (Libellula vibrans) was spotted near a vernal pool in the forest at Huntley Meadows Park (HMP), Fairfax County, Virginia USA. This individual is a mature female, as indicated by her terminal appendages, discolored abdomen, and tattered wings.

Female Great Blue Skimmers have a pair of flanges beneath their eighth abdominal segment that are used to scoop and hold a few drops of water when laying eggs (oviposition), hence the family name “Skimmer.” Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.

Related Resources

Copyright © 2017 Walter Sanford. All rights reserved.

Powdered Dancer (males, female)

August 20, 2017

A Powdered Dancer damselfly (Argia moesta) was spotted during a photowalk along a mid-size rocky stream in Fairfax County, Virginia USA. This individual is a male, as indicated by his terminal appendages. There is a whitish-blue morph female Powdered Dancer, therefore the male’s whitish-blue coloration is insufficient to identify its gender.

21 JUN 2017 | Fairfax County, VA | Powdered Dancer (male)

A week later, a mating pair of Powdered Dancers was spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This pair is “in tandem“: the male is on the upper-left; the female on the lower-right.

28 JUN 2017 | Riverbend Park | Powdered Dancers (mating pair, in tandem)

The male is “contact guarding” the female as the pair flies “in tandem” to egg-laying sites where the female uses her ovipositor to insert eggs into vegetation (endophytic oviposition).

It’s helpful to take photos of mating pairs of damselflies, especially “in tandem,” since males and females of the same species can look quite different.

Female Powdered Dancers are polymorphic, including a whitish-blue andromorph and a brown heteromorph. The brown morph, shown in this pair, is more common than whitish-blue.

28 JUN 2017 | Riverbend Park | Powdered Dancers (mating pair, in tandem)

Did you notice the male Stream Bluet damselfly (Enallagma exsulans) perching near the Powdered Dancers? Thanks to Karen Kearney and Michael Boatwright, members of the Virginia Odonata Facebook group, for confirming my tentative identification of the Stream Bluet.

Copyright © 2017 Walter Sanford. All rights reserved.

Banded Pennants (mating pair, in wheel)

August 8, 2017

“In wheel”

A mating pair of Banded Pennant dragonflies (Celithemis fasciata) was spotted at Mulligan Pond, Jackson Miles Abbott Wetland Refuge (JMAWR), Fairfax County, Virginia USA. This pair is “in wheel.”

02 AUG 2017 | JMAWR | Banded Pennants (mating pair, “in wheel“)

02 AUG 2017 | JMAWR | Banded Pennants (mating pair, “in wheel“)

“Insex”

In a recent blog post, I mentioned that I used to photowalk the boardwalk at Huntley Meadows Park frequently. In deference to the many women and children who visit the park, I coined the term “insex” (sounds like “insects” to the uninitiated) as a family-friendly way to alert my fellow odonate hunters/photowalkers that I heard/saw a mating pair of dragonflies.

More often than not, I hear the clatter of wings before I see a mating pair. When I hear that unique sound, “insex” is the code word I use to give people a heads-up to search for the noisy couple.

In this case, the male Banded Pennant made a silky-smooth, soundless hook-up with the female. I had been watching the female oviposit along the shoreline of the pond while a male was hover guarding her. The fact is, I’m not sure whether he was actually hover guarding or an interloper waiting for an opportunity to grab the female. Either way, I was able to shoot just two photos of the mating pair before they flew in wheel to the top of a nearby tree.

Copyright © 2017 Walter Sanford. All rights reserved.


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