Archive for the ‘damselflies’ Category

Familiar Bluet damselfly (female)

February 2, 2018

A Familiar Bluet damselfly (Enallagma civile) was spotted near a drainage ditch at a remote location in Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a female.

The damselfly appears to be eating a smaller black insect, possibly a spider.

Editor’s Note: Sincere thanks to Mike Boatwright for verifying my tentative identification of the damselfly.

Copyright © 2018 Walter Sanford. All rights reserved.

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Dragonflies and Damselflies (poster, slideshow)

January 3, 2018

 

D R A G O N F L I E S  A N D  D A M S E L F L I E S
HUNTLEY MEADOWS PARK

W A L T E R  S A N F O R D
Educator | Naturalist | Photographer

 

Copyright © 2018 Walter Sanford. All rights reserved.

Top 10 Photos of 2017

January 1, 2018

The following gallery shows 32 finalists for my “Top 10 Photos of 2017.” The photos are presented in reverse-chronological order beginning in November 2017 and ending in April 2017.

The Top 10 photos will be selected using reader feedback. Please enter a comment at the end of this post listing the number for each of your 10 favorite photos. If listing 10 photos is asking too much, then please list at least five photos, e.g., No. 5, 8, 14, 17, 21, etc. Thanks for sharing your selections, and thanks for following my photoblog!

No. 1

No. 2

No. 3

27 OCT 2017 | MRA | Autumn Meadowhawk (mating pair, “in tandem“)

No. 4

No. 5

No. 6

No. 7

No. 8

No. 9

No. 10

No. 11

No. 12

No. 13

No. 14

No. 15

No. 16

No. 17

No. 18

No. 19

No. 20

No. 21

20 JUN 2017 | OBNWR | Calico Pennant (immature male)

No. 22

No. 23

10 MAY 2017 | HORP | crayfish (underwater)

No. 24

No. 25

No. 26

No. 27

No. 28

No. 29

No. 30

No. 31

No. 32

Editor’s Note: The following location codes are used in some photo captions, shown above.

Copyright © 2018 Walter Sanford. All rights reserved.

Visualizing data temporally: Damselflies

December 16, 2017

Google Calendar and Dr. Steve Roble’s excellent datasets for the Commonwealth of Virginia were used to synthesize “CHECKLIST OF THE DRAGONFLIES AND DAMSELFLIES OF VIRGINIA, April 2017 update” into two calendars: Dragonflies (VA Flight Dates); and Damselflies (VA Flight Dates). Dragonflies was presented in my last blog post; Damselflies is presented in this post.

The Damselflies calendar is color-coded Birch, using the Google Calendar default color palette. Individual events on the calendar are also color-coded by family. Here’s the way Damselflies looks using the Chrome Web browser on my Apple iMac desktop computer.

And here’s the way the calendar looks using the free Google Calendar app on my Apple iPad mini 2.

Every event features the following information: common name; scientific name; early-date/late-date; abundance; and habitat.

Regrettably, the color-coding is lost when the calendar is exported as an “.ics” file. That’s the bad news. The good news is the calendar can be edited after it is imported into Google Calendar and it’s easy to edit the entries to color-code them any way you like.

“RGB” 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.

  • R – Family Calopterygidae (Broad-winged Damselflies) [Tomato]
  • B – Family Coenagrionidae (Narrow-winged Damselflies) [Peacock]
  • G – Family Lestidae (Spreadwings) [Basil]

The colors for Narrow-winged Damselflies and Spreadwings were flip-flopped because it just makes sense the Bluets should be color-coded blue!

Tech Tips

Download the “.ics” file from the Virginia Odonata Facebook group. Launch Google Calendar on a desktop computer. Create a new calendar by clicking on the “+” symbol to the left of “Add a friend’s calendar.” (Yeah, yeah — I realize that’s counterintuitive!) Give the calendar a name such as “Test Calendar” and click on the “Create Calendar” button. (You can change the name later.) “Test Calendar” should appear in the list of calendars under “My calendars.”

Mouse-over the name “Test Calendar” and click on the vertical column of three dots, labeled “Options for Test Calendar” then select “Settings and sharing.” In the upper-left sidebar, click on “Import and export”; select the “.ics” file to import and select “Test Calendar” from the drop-down menu labeled “Add to calendar.”

If you decide to color-code individual events like I did, click on an event then click on the pencil icon labeled “Edit event.” Select a color and click the “Save” button, then click the radio button for “All events.” Beware: You can right-click on an individual event and change its color but DON’T GO THERE! That results in an event that doesn’t occur annually using the new color you chose.

Related Resource

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

Copyright © 2017 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.

Lentic and lotic

October 3, 2017

Doesn’t this idyllic place look like ideal habitat for lotic species of odonates? It is!

Lotic refers to flowing water, from the Latin lotus, washed. … Lotic ecosystems can be contrasted with lentic ecosystems, which involve relatively still terrestrial waters such as lakes and ponds. Source Credit: River ecosystem, Wikipedia.

The preceding photo shows the stream crossing at Popes Head Creek, Hemlock Overlook Regional Park, Fairfax County, Virginia USA (facing downstream toward Bull Run). Both streams provide ideal habitat for many species of dragonflies and damselflies that prefer flowing water rather than still water.

Tech Tip: I used my Panasonic Lumix DMC-FZ150 superzoom camera to shoot the landscape photo featured in this blog post. The camera was set for manual focus at the hyperfocal distance for an aperture of f/4, based upon the instructions provided in the excellent video tutorial by Graham Houghton, “Panasonic Lumix FZ camera easier manual focus method — super point-and-shoot tip.”

Copyright © 2017 Walter Sanford. All rights reserved.

The ugly side of Mother Nature

October 1, 2017

A Big Bluet damselfly (Enallagma durum) was spotted during a photowalk along Deephole Point Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is a male, eating a teneral damselfly.

10 SEP 2017 | Occoquan Bay NWR | Big Bluet (male, eating prey)

I think they may both be Big Bluets. Source Credit: Michael Moore, Virginia Odonata Facebook group.

Some species of odonates are cannibals, that is, they feed on their own species. And there it is — the ugly side of Mother Nature!

Copyright © 2017 Walter Sanford. All rights reserved.

Big Bluet damselfly (mating pairs)

September 3, 2017

Hundreds, if not thousands, of Big Bluet damselflies (Enallagma durum) were spotted on 30 August 2017 during a photowalk along Deephole Point Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

A mating pair of Big Bluet was spotted “in heart.” The male is on the upper-right; the female on the lower-left.

30 AUG 2017 | OBNWR | Big Bluet (mating pair, “in heart“)

Big Bluet females are polymorphic, including a blue morph and brown morph. The female in this mating pair is a blue andromorph.

30 AUG 2017 | OBNWR | Big Bluet (mating pair, “in heart“)

I photographed the following male because he was perching at the right height for me to take the shot while standing. I took one photo before he flew to another perch, closer to the ground.

30 AUG 2017 | OBNWR | Big Bluet (male)

As it turns out, the single male led me to another mating pair of Big Bluet that I hadn’t noticed!

30 AUG 2017 | OBNWR | Big Bluet (mating pair, “in heart“)

The female in the preceding mating pair is a brown heteromorph. Color is a highly variable field marker, and describing color is subjective. In my experience, the heteromorph female Big Bluets native to Northern Virginia are light tan to light olive drab in color.

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.


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