Posts Tagged ‘oviposition’

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.

Autumn Meadowhawks (males and females)

November 5, 2015

Autumn Meadowhawk (Sympetrum vicinum) is a member of the Skimmer Family of dragonflies that is commonly spotted during the fall months at many water bodies in the mid-Atlantic United States, such as the vernal pools and central wetland area at Huntley Meadows Park.

The first individual is a male, as indicated by its coloration and terminal appendages. By the first week in November, fall foliage is past peak color and the ground is covered almost completely by leaf litter.

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male.

04 NOV 2015 | Huntley Meadows Park | Autumn Meadowhawk (male)

The following photo shows another male, spotted a couple of weeks earlier.

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male.

21 OCT 2015 | Huntley Meadows Park | Autumn Meadowhawk (male)

The next Autumn Meadowhawk is a female, as indicated by its coloration and terminal appendages. Female abdomens are slightly thicker than those of males and noticeably flared toward both the thorax and tip of the abdomen. The “subgenital plate,” located under the ninth abdominal segment (S9), is a large scoop-like structure used for laying eggs (exophytic oviposition).

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

15 OCT 2015 | Huntley Meadows Park | Autumn Meadowhawk (female)

The last individual is another female. Regular readers of my photoblog know I’m especially fond of head-tilts in which the dragonfly seems to display some of its personality.

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

15 OCT 2015 | Huntley Meadows Park | Autumn Meadowhawk (female)

Copyright © 2015 Walter Sanford. All rights reserved.

Great Spreadwing (mating pairs, in tandem)

October 30, 2015

Every year I set goals for odonate hunting. One goal for 2015: spot and photograph a female Great Spreadwing damselfly (Archilestes grandis). Although I never saw a solo female, I was fortunate to photograph several mating pairs at Huntley Meadows Park (HMP).

After copulation, Great Spreadwings engage in a form of guarding behavior known as “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 Great Spreadwing damselflies (Archilestes grandis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is in tandem.

11 OCT 2015 | HMP | Great Spreadwing (mating pair, in tandem)

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

Look closely at the tip of the female’s abdomen. Notice several anatomical structures: two cerci (sing. cercus), superior appendages that have little or no function; two styli (sing. stylus), structures that serve as sensors (like “curb feelers“) in egg positioning during oviposition; and an ovipositor that is used to insert eggs into vegetation (endophytic oviposition).

A mating pair of Great Spreadwing damselflies (Archilestes grandis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is in tandem; the female is shown ovipositing.

21 OCT 2015 | HMP | Great Spreadwing (mating pair, in tandem)

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

The female is ovipositing in two similar-looking photos, shown above and below. Look closely at the full-size version of both photos: the preceding photo shows the ovipositor hasn’t penetrated the vegetation; the following photo shows the ovipositor has been inserted in the plant stem.

A mating pair of Great Spreadwing damselflies (Archilestes grandis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is in tandem; the female is shown ovipositing.

21 OCT 2015 | HMP | Great Spreadwing (mating pair, in tandem)

The male guided the female around-and-around a small vernal pool for at least 30 minutes, with brief stops for egg-laying at selected sites. The last photo shows the same mating pair taking a rest break. Notice the mud on the female’s wings and abdomen.

Ooooh, I need a dirty woman. Ooooh, I need a dirty girl. Source Credit: Young Lust, by Pink Floyd.

A mating pair of Great Spreadwing damselflies (Archilestes grandis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is in tandem.

21 OCT 2015 | HMP | Great Spreadwing (mating pair, in tandem)

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

Copyright © 2015 Walter Sanford. All rights reserved.

Slender Spreadwing damselfly (female)

October 14, 2015

The following gallery of photos features a Slender Spreadwing damselfly (Lestes rectangularis) spotted near a vernal pool at Huntley Meadows Park (HMP). This individual is a female, as indicated by its terminal appendages and the ovipositor located on the underside of the posterior abdomen. The ovipositor is used to insert eggs into vegetation (endophytic oviposition).

A Slender Spreadwing damselfly (Lestes rectangularis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

08 OCT 2015 | HMP | Slender Spreadwing (female)

See a full-size version of the preceding photo, without annotation.

A Slender Spreadwing damselfly (Lestes rectangularis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

08 OCT 2015 | HMP | Slender Spreadwing (female)

Look closely at the tip of the female’s abdomen. Notice a couple of anatomical structures: two cerci (sing. cercus), superior appendages that have little or no function; and two styli (sing. stylus), structures that serve as sensors (like “curb feelers“) in egg positioning during oviposition.

A Slender Spreadwing damselfly (Lestes rectangularis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

08 OCT 2015 | HMP | Slender Spreadwing (female)

See a full-size version of the preceding photo, without annotation. Adobe Photoshop was used to remove a couple of small distracting elements from the photo.

The last two photos provide a good side view of the ovipositor.

A Slender Spreadwing damselfly (Lestes rectangularis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

08 OCT 2015 | HMP | Slender Spreadwing (female)

A Slender Spreadwing damselfly (Lestes rectangularis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

08 OCT 2015 | HMP | Slender Spreadwing (female)

Related Resource: Odonate Terminal Appendages.

Copyright © 2015 Walter Sanford. All rights reserved.

Full Circle

August 21, 2015

A mating pair of Common Green Darners (Anax junius) was spotted at a bioswale near the head-end of the Hike-Bike Trail at Huntley Meadows Park (HMP).

The bioswale was designed to filter the runoff which comes from the parking lot, removing heavy metals, salt, sand, etc. from the runoff before conveyance to Dogue Creek. It is supposed to slowly filter the rain water in 48-72 hours, to clean and purify the water before entering the creek. Source Credit: David M. Lawlor, Natural Resource Manager, HMP.

The pair is in tandem (a form of guarding behavior): the male (upper-right) guides the female (lower-left) to places where she can lay eggs in vegetation (endophytic oviposition).

A mating pair of Common Green Darner dragonflies (Anax junius) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is in tandem as the female lays eggs by the process of oviposition.

05 AUG 2015 | HMP | Common Green Darner (mating pair, in tandem)

Did you notice the odonate exuvia located on the same reed as the Common Green Darners? Although it’s usually impossible to identify an exuvia from a photograph like the one shown above, I consulted the experts of the Northeast Odonata Facebook group.

I can’t identify the exuvia to species, but I’m pretty confident about the family — Libellulidae, a skimmer. Possibly Blue Dasher, but I’m mostly guessing there. Source Credit: Christopher E. Hill, Associate Professor, Department of Biology, Coastal Carolina University.

A mating pair of Common Green Darner dragonflies (Anax junius) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is in tandem as the female lays eggs by the process of oviposition.

05 AUG 2015 | HMP | Common Green Darner (mating pair, in tandem)

Eggs may hatch after a few days, or embryonic development may take a month or more. In some species, the eggs overwinter and hatch the following spring. Each egg hatches into a very tiny prolarva that looks like a primitive insect form, quite different from the larva that will succeed it. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 407-409). Princeton University Press. Kindle Edition.

As odonate larvae grow and outgrow their skin, they molt, on average 12 times. The duration of this stage of life can vary from a month to several years, depending upon both species and climate. The last molt, called “emergence,” is the metamorphosis from larva to adult; the “cast skin” that is left behind is an exuvia (pl. exuviae).

The juxtaposition of the exuvia and mating pair in the first photo is a metaphor for the circle of life, come full circle: eggs; prolarvae; larvae; emergence/adult males and females; mating pairs; males guide females to egg-laying sites.

Related Resources:

Copyright © 2015 Walter Sanford. All rights reserved.

A Southern Fortnight, Part 6 – Damselfly reproductive anatomy

August 19, 2015

The Backstory: A Southern Fortnight

For the first two weeks during May 2015, Southern Spreadwing damselflies (Lestes australis) were observed at a vernal pool and nearby drainage ditch in the forest at Huntley Meadows Park. I spotted approximately six males and several females during the fortnight. Their sudden disappearance seemed to coincide with a population explosion of Eastern Pondhawk dragonflies (Erythemis simplicicollis) in mid-May. Eastern Pondhawks, especially females, are voracious predators with a penchant for preying upon damselflies.


The following annotated image illustrates some of the reproductive anatomy of male and female Southern Spreadwing damselflies.

A mating pair of Southern Spreadwing damselflies (Lestes australis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is in tandem; the female is laying eggs (oviposition).

08 MAY 2015 | HMP | Southern Spreadwing (mating pair, in tandem)

The following annotated image illustrates some of the reproductive anatomy of a female Southern Spreadwing: two cerci (sing. cercus), superior appendages that have little or no function; two styli (sing. stylus), structures that serve as sensors in egg positioning; and an ovipositor  (shown above) that is used to insert eggs into vegetation (endophytic oviposition).

A Southern Spreadwing damselfly (Lestes australis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This is the female member of a mating pair, resting after laying eggs (oviposition).

07 MAY 2015 | HMP | Southern Spreadwing (adult female)

According to Ed Lam, author and illustrator of Damselflies of the Northeast, “male Southern and Sweetflag cannot be separated in the field.” It is possible to reverse-engineer a positive identification based upon a single key field marker for female specimens of the two species: Southern Spreadwing females have a much smaller ovipositor than Sweetflag Spreadwing females, as illustrated in the following references.

Sidebar: Damselfly Hook-up and Copulation

After a male damselfly grabs a female with his claspers, he transfers sperm from the genital opening under the ninth abdominal segment (S9) to his hamules, shown above, located beneath the second abdominal segment (S2). Next the pair forms the mating wheel, then the male transfers sperm from his hamules to the female through her genital pore under the eighth abdominal segment (S8). The beginning-to-end process is shown in the following still photos and two-part series of videos.

Digital Scans:

Copyright © 2015 Walter Sanford. All rights reserved.


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