Archive for the ‘damselflies’ Category

A Beginners’ Guide to Identifying the Exuviae of Wisconsin Odonata to Family

May 25, 2021

A Beginners’ Guide to Identifying the Exuviae of Wisconsin Odonata to Family, by Freda Van den Broek and Walter Sanford was published in the Spring 2021 issue of the Wisconsin Dragonfly Society newsletter.

The article is richly illustrated with lots of photographs, many annotated, and includes a decision tree flow chart for identifying dragonfly and damselfly exuviae to the family level, plus a photo-illustrated glossary.

Wisconsin Odonata News | Vol. 9 Issue 1 | Spring 2021

Although the guide is focused primarily on odonate exuviae found in Wisconsin, it should be useful for any location in the United States of America.

Giving credit where credit is due

Freda Van den Broek did most of the heavy lifting; my contribution was modest. Congratulations for a job well done, Freda — it was a pleasure working with you!

Copyright © 2021 Walter Sanford. All rights reserved.

Odonate calendars updated for 2021

March 16, 2021

Google Calendar was used to synthesize Dr. Steve Roble’s excellent datasets for the Commonwealth of Virginia into two calendars: Dragonflies (VA Flight Dates); and Damselflies (VA Flight Dates). An online, interactive version of both calendars is provided on this page.

Dragonflies (VA Flight Dates) – Updated for 2021

The dragonflies calendar is shown below. Every event features the following information: common name; scientific name; early-date/late-date; abundance; and habitat.

Damselflies (VA Flight Dates) – Updated for 2021

An interactive version of the damselflies calendar is also available online, as shown below. Every event features the following information: common name; scientific name; early-date/late-date; abundance; and habitat.

Color-coded versions

Both calendars are color-coded by family. Regrettably, the color-coding is lost in the online, interactive version of both calendars. That is, unless you print the .ics version of the calendars (samples shown below). Please contact me if you would to have copies of the .ics versions of the calendars.

The colors of the rainbow (ROYGBIV) were used to color-code the seven families of dragonflies; the equivalent colors in the Google Calendar default color palette are shown in brackets. The colors for Emeralds and Clubtails were flip-flopped because it just makes sense the Emeralds should be color-coded green!

  • R = Family Aeshnidae (Darners) [Tomato]
  • O = Family Cordulegastridae (Spiketails) [Tangerine]
  • G = Family Corduliidae (Emeralds) [Basil]
  • Y = Family Gomphidae (Clubtails) [Banana]
  • B = Family Libellulidae (Skimmers) [Peacock]
  • I = Family Macromiidae (Cruisers) [Blueberry]
  • V = Family Petaluridae (Petaltails) [Grape]

Dragonflies (VA Flight Dates) – March 2021

“FSL” was used to color-code the three families of damselflies common to the mid-Atlantic states (USA); the equivalent colors in the Google Calendar default color palette are shown in brackets.

  • F – Family Calopterygidae (Broad-winged Damselflies) [Flamingo]
  • S – Family Coenagrionidae (Narrow-winged Damselflies) [Sage]
  • L – Family Lestidae (Spreadwings) [Lavendar]

For what it’s worth, all of the colors for the damselflies calendar are pastel shades.

Damselflies (VA Flight Dates) – March 2021

Related Resources

CHECKLIST OF THE DRAGONFLIES AND DAMSELFLIES OF VIRGINIA, April 2017 and April 2020 updates” by Dr. Steve Roble, Staff Zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage.

Kevin Munroe, former manager of Huntley Meadows Park, created an excellent calendar called Dragonflies of Northern Virginia – Flight Periods. This calendar is a valuable resource for hunting dragonflies in Northern Virginia. I think the value of Kevin Munroe’s calendar is enhanced by using it in combination with my visualization of Dr. Steve Roble’s dataset.

Dragonflies & Damselflies of Loudoun County features a flight calendar for both dragonflies and damselflies.

Copyright © 2021 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.

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.

Big Bluet damselfly (male)

September 25, 2020

A Big Bluet damselfly (Enallagma durum) was spotted during a photowalk with Michael Powell along Deephole Point Road at Occoquan Bay National Wildlife Refuge (OBNWR), Prince William County, Virginia USA.

This individual — one of hundreds, if not thousands we saw while hunting for a rare to uncommon species of dragonfly — is a male, as indicated by his blue and black coloration and terminal appendages.

15 SEP 2020 | OBNWR | Big Bluet (male)

Ideal habitat for Big Bluet is as follows.

Habitat Large sandy lakes and lower reaches of rivers, even extending into brackish estuaries. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 2156-2157). Princeton University Press. Kindle Edition.

Think large, tidal rivers and bays. I have observed E. durum at Dyke Marsh Wildlife Preserve, Accotink Bay Wildlife Refuge, and Occoquan Bay National Wildlife Refuge.

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

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 Big Bluet isn’t on the list, although there are several species of Enallagma that aren’t found where I live in Fairfax County, Virginia USA.

Copyright © 2020 Walter Sanford. All rights reserved.

Blue-fronted Dancer damselfly

August 31, 2020

A Blue-fronted Dancer damselfly (Argia apicalis) was spotted during a photowalk with Michael Powell near Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR), Fairfax County, Virginia USA.

A. apicalis has “a blue form female and a brown form female.” Since neither the hamules nor terminal appendages can be seen clearly in the preceding photo, I’m unsure whether this individual is male or female.

Post Update

Michael Ready, good friend and fellow member of the Dragonfly Society of the Americas, shared the following comment via e-mail.

That’s an outstanding picture of a Blue-fronted Dancer. You state you are unsure of the individual’s gender. I am confident that it is a male. According to my field guides (Lam and Paulson), the blue-form female lacks the blue eyes and blue S8-10 that are apparent in your picture. Source Credit: Michael Ready.

Thanks for the kind words and helpful information, Michael! As it turns out, the field marks that you described are shown clearly in one of my blog posts: Blue-fronted Dancers (male, female), especially this photo.

Copyright © 2020 Walter Sanford. All rights reserved.

We have a history

August 21, 2020

An Eastern Pondhawk dragonfly (Erythemis simplicicollis) was spotted during a photowalk with Michael Powell near Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR) in Fairfax County, Virginia USA.

This individual is a female, as indicated by her coloration and terminal appendages. Eastern Pondhawk, especially female E. simplicicollis, are voracious predators.

18 AUG 2020 | JMAWR | Eastern Pondhawk (female)

Regular readers of my blog know I love me some head-tilts, as shown in the preceding photo.

18 AUG 2020 | JMAWR | Eastern Pondhawk (female)

The Backstory

As the title of this blog post suggests, Eastern Pondhawk and I have a history — a negative history. A cohort of Southern Spreadwing damselflies (Lestes australis) was observed for a two-week period during early May 2015 at a vernal pool in the forest at Huntley Meadows Park.

The sudden disappearance of the damselfly cohort seemed to coincide with a population explosion of Eastern Pondhawk in mid-May. After years of heavy predation by Eastern Pondhawk, Southern Spreadwing disappeared completely from the vernal pool.

Related Resource: A Southern Fortnight – Part 1-7.

Copyright © 2020 Walter Sanford. All rights reserved.

Acceptable uncertainty

July 27, 2020

A teneral damselfly was spotted by Michael Powell during a photowalk with me along a mid-size stream in Fairfax County, Virginia USA.

teneral: adult after it has just emerged, soft and not definitively colored. Source Credit: Glossary [of] Some Dragonfly Terms, by Dennis Paulson.

Teneral odonates, especially females, can be challenging at best to identify with certainty. And so it is with this one.

The first photo is the record shot. (Get a shot, any shot.) I think I might have just missed focus on the face.

No. 1 | 15 JUL 2020 | Fairfax County, VA | teneral damselfly

Refine the shot.

No. 2 | 15 JUL 2020 | Fairfax County, VA | teneral damselfly

Although this individual is definitely a member of Family Coenagrionidae (Narrow-winged Damselflies), both the genus/species and gender are somewhat uncertain.

It appears to be an Argia sp. based on long tibial spines. I think it is a male. Source Credit: Mike Boatwright, founder and administrator of the Virginia Odonata Facebook group.

For what it’s worth, Mike Powell and I saw three species of damselflies during our outing: Blue-tipped Dancer (Argia tibialis); Dusky Dancer (Argia translata); and Powdered Dancer (Argia moesta).

I’m not sure of the gender. I see what might be hamules, indicating this individual is male, but also see what looks like a female stylus (plural: styli) near the tip of the abdomen, indicating this might be a female.

Bonus Bugs and More

Look closely at Photo No. 1, the “record shot.” Notice the small orange colored insect perched along the bottom of the same rock on which the damselfly is perched. Can anyone identify Bonus Bug No. 1?

Post Update: “The fly at the [bottom] of this photo may be a black fly (Simuliidae).” Source Credit: John Smith, member “BugGuide” Facebook group.

Now look at Photo No. 2. Notice there is some type of dark insect that’s perched along the same edge of the rock as the damselfly. Can anyone identify Bonus Bug No. 2?

Post Update: “The bug at the bottom of your photo appears to be a caddisfly.” Source Credit: John Smith, member “BugGuide” Facebook group.

Also notice the dark insect is perched near what might be the exuvia from which the damselfly emerged, as shown in Photo No. 2. It’s tannish in coloration.

I didn’t see either the bonus bugs or possible exuvia when we were in the field. Of course!

Related Resource: Newly emerged damselflies, a companion blog post by Michael Powell.

Copyright © 2020 Walter Sanford. All rights reserved.

Blue-tipped Dancer damselfly (male)

July 17, 2020

A Blue-tipped Dancer damselfly (Argia tibialis) was spotted during a photowalk with Michael Powell along a mid-size stream in Fairfax County, Virginia USA. Blue-tipped Dancer is a member of Family Coenagrionidae (Narrow-winged Damselflies).

This individual is a male. I love the gun metal gray color of his upper thorax stripes.

15 JUL 2020 | Fairfax County, VA | Blue-tipped Dancer (male)

Related Resource: A. tibialis male #4 (Blue-tipped Dancer)

Credit

Thanks to Michael Boatwright, founder and administrator of the Virginia Odonata Facebook group, for help in identifying this specimen.

Copyright © 2020 Walter Sanford. All rights reserved.

Odonate Calendars (updated for 2020)

July 15, 2020

Phenology (noun) is defined as “the study of cyclic and seasonal natural phenomena, especially in relation to climate and plant and animal life.”

There is an annual cycle of odonate activity that can be subdivided into three broad categories: Early Season (spring); Mid-season (summer); and Late Season (fall).

A calendar is a good way to visualize odonate phenology. I created a new blog page called “Odonate Calendars” (see right sidebar) that features several calendars showing the adult flight period for all species of dragonflies and damselflies that can be found in the Commonwealth of Virginia.

The page includes two interactive calendars for Dr. Steve Roble’s excellent datasets for the Commonwealth of Virginia: one for dragonflies; another for damselflies. Other calendars are provided under “Related Resources.”

Copyright © 2020 Walter Sanford. All rights reserved.


%d bloggers like this: