Posts Tagged ‘contact guarding’

Autumn Meadowhawk dragonflies (mating pairs)

November 4, 2017

This blog post features more photos taken using my Fujifilm X-T1 digital camera, Fujinon XF55-200mm zoom lens, and a Fujifilm MCEX-11 extension tube. The camera was set for manual focus in order to use focus peaking; back-button focusing was used to focus automatically.

In wheel

ISO 640 | 200mm (~300mm, 35mm equivalent) | f/11 | 1/500s | 0.33 ev

Two of many mating pairs of Autumn Meadowhawk dragonflies (Sympetrum vicinum) were photographed on 27 October 2017 at Hidden Pond, Meadowood Recreation Area, Fairfax County, Virginia USA. Both pairs are “in wheel“: the male is on top; the female is on the bottom.

ISO 800 | 200mm (~300mm, 35mm equivalent) | f/18 | 1/500s | 0 ev

In tandem

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

ISO 800 | 200mm (~300mm, 35mm equivalent) | f/16 | 1/500s | 0 ev

After copulation, Autumn Meadowhawks 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.

Related Resource: Adding an 11mm extension tube, a blog post by Walter Sanford.

Copyright © 2017 Walter Sanford. All rights reserved.

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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.

Tiny Dancer

August 13, 2015

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

Several species of Argia are relatively common in Northern Virginia parks: Blue-tipped Dancer and Variable Dancer are featured in this post; Blue-fronted Dancer was featured in a recent blog post.

Blue-tipped Dancer

The first photo shows a Blue-tipped Dancer damselfly (Argia tibialis) perching on a sandy beach in the stream bed of Dogue Creek, Wickford Park. This individual is a male, as indicated by its coloration.

A Blue-tipped Dancer damselfly (Argia tibialis) spotted at Dogue Creek, Wickford Park, Fairfax County, Virginia USA. This individual is a male.

05 AUG 2015 | Wickford Park | Blue-tipped Dancer (male)

Variable Dancer

The next photo shows a Variable Dancer damselfly (Argia fumipennis) perching on vegetation along Dogue Creek, near Huntley Meadows Park. This individual is a male, as indicated by its coloration.

A Variable Dancer damselfly (Argia fumipennis) spotted at Dogue Creek near Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male.

05 AUG 2015 | Dogue Creek | Variable Dancer (male)

The last photo shows a mating pair of Variable Dancer damselflies (Argia fumipennis) spotted at Huntley Meadows Park (HMP). The pair is in tandem (a form of guarding behavior): the male (upper-left) guides the female (lower-right) to places where she can lay eggs in vegetation (endophytic oviposition).

A mating pair of Variable Dancer damselflies (Argia fumipennis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. The pair is in tandem.

05 AUG 2015 | HMP | Variable Dancer (mating pair, in tandem)

It’s helpful to get shots of mating pairs 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 Argia (Dancers) fit 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!

Editor’s Note: Please comment to let me know whether the preceding information is helpful.

Related Resources:

Copyright © 2015 Walter Sanford. All rights reserved.


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