Posts Tagged ‘oviposition’

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.

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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.

More Big Bluet damselflies

December 24, 2016

More Big Bluet damselflies (Enallagma durum) were spotted in July 2016 during two photowalks along the Potomac River at Dyke Marsh Wildlife Preserve (DMWP).

More males

These individuals are males, as indicated by their blue and black coloration and by their terminal appendages.

Mating pair

The mating pair of Big Bluet damselflies shown in the following photograph is “in wheel,” in which the male uses “claspers” (terminal appendages) at the end of his abdomen to hold the female by her neck/thorax while they are joined at their abdomens. The male, blue and black in color, is on top; the female, green and black in color, is on the bottom.

The copulatory, or wheel, position is unique to the Odonata, as is the distant separation of the male’s genital opening and copulatory organs. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 377-378). Princeton University Press. Kindle Edition.

The wheel position is sometimes referred to as “in heart” when damselflies mate. In this case, the heart shape is deformed slightly.

A mating pair of Big Bluet damselflies (Enallagma durum) spotted at Dyke Marsh Wildlife Preserve, Fairfax County, Virginia USA. This pair is "in heart."

19 JUL 2016 | DMWP | Big Bluet (mating pair, “in tandem”)

The same pair is “in tandem” a while later: the male is on the right; the female is on the left. The male is engaged in “contact guarding,” in which the male and female fly “in tandem” to egg-laying sites. Contact guarding is used by some species of odonates to prevent aggressive males from hijacking the female.

A mating pair of Big Bluet damselflies (Enallagma durum) spotted at Dyke Marsh Wildlife Preserve, Fairfax County, Virginia USA. This pair is "in tandem."

19 JUL 2016 | DMWP | Big Bluet (mating pair, “in tandem”)

Look closely at the underside of the female’s abdomen, near the tip. Notice the ovipositor that she uses 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.

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

Family Calopterygidae is comprised of two genera.

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

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 Resources: Excellent digital scans created by Gayle and Jeanelle Strickland. Click on the button labeled “Download file” in order to view full-size version of the graphics.

  • Enallagma durum male #4 | male | JPG
  • Enallagma durum female #2 | female | JPG

Copyright © 2016 Walter Sanford. All rights reserved.

Dusky Dancer damselflies (mating pair)

September 12, 2016

A mating pair of Dusky Dancer damselflies (Argia translata) was spotted along Pope’s Head Creek at Chapel Road Park. Dusky Dancer is a new species on my life list of odonates.

This pair is “in tandem“: the male is on the upper-right; the female is on the lower-left.

A mating pair of Dusky Dancer damselflies (Argia translata) spotted along Pope's Head Creek at Chapel Road Park, Fairfax County, Virginia USA. This pair is "in tandem."

29 AUG 2016 | Chapel Road Park | Dusky Dancer (mating pair)

The male is on the upper-left in the following photo; the female is on the lower-right. The male is engaged in “contact guarding,” in which the male and female fly “in tandem” to egg-laying sites. The female is ovipositing in a partially submerged leaf.

A mating pair of Dusky Dancer damselflies (Argia translata) spotted along Pope's Head Creek at Chapel Road Park, Fairfax County, Virginia USA. This pair is "in tandem."

29 AUG 2016 | Chapel Road Park | Dusky Dancer (mating pair)

Related Resource: A. translata male (Dusky Dancer) [JPG] [digital scan].

Copyright © 2016 Walter Sanford. All rights reserved.

Swamp Darner dragonfly (female, oviposition)

April 27, 2016

The cavalcade of spring species of odonates continues: a first-of-season Swamp Darner dragonfly (Epiaeschna heros) was spotted on 25 April 2016 near a vernal pool at a remote location in Huntley Meadows Park.

A Swamp Darner dragonfly (Epiaeschna heros) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female, laying eggs (oviposition) in soft wood.

This individual is a female, laying eggs (oviposition) in soft wood. All female damselflies and many female dragonflies, especially Aeschnidae, have an ovipositor that is used to puncture aquatic plants, logs, wet mud, etc.; eggs are placed singly in the puncture. The ovipositor is clearly visible in the following annotated image.

A Swamp Darner dragonfly (Epiaeschna heros) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female, laying eggs (oviposition) in soft wood.

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

Related Resource: Swamp Darner Ovipositing in Rotting Log (NJ, USA), an excellent YouTube video (2:03) published on June 5, 2014, shot from the edge of a vernal pool located in New Jersey.

Copyright © 2016 Walter Sanford. All rights reserved.


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