Posts Tagged ‘pruinescence’

Widow Skimmer dragonfly (mature male)

August 23, 2019

A Widow Skimmer dragonfly (Libellula luctuosa) was spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

16 AUG 2019 | Occoquan Bay NWR | Widow Skimmer (mature male)

This individual is a mature male, as indicated by the white pruinescence on his thorax and abdomen, pattern of wing spots (contrast with female pattern of wing spots), and terminal appendages.

This male has mated many times, as indicated by the scratch marks on his abdomen.

Males that have mated often have marks on their abdomen where the female legs have scratched them. This is especially obvious in species in which males develop pruinosity, as the pruinosity on the mid-abdomen is scratched off, and the signs are visible at some distance. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 390-392). Princeton University Press. Kindle Edition.

Copyright © 2019 Walter Sanford. All rights reserved.

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Common Whitetail (mature male)

August 21, 2019

Common Whitetail dragonfly (Plathemis lydia) was spotted near the Painted Turtle Pond Environmental Study AreaOccoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

This individual is a mature male, as indicated by the white coloration of his abdomen, pattern of wing spots, and terminal appendages. He is perched vertically on the corner of a storage shed.

16 AUG 2019 | Occoquan Bay NWR | Common Whitetail (mature male)

This male has mated many times, as indicated by the scratch marks on his abdomen.

Males that have mated often have marks on their abdomen where the female legs have scratched them. This is especially obvious in species in which males develop pruinosity, as the pruinosity on the mid-abdomen is scratched off, and the signs are visible at some distance. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 390-392). Princeton University Press. Kindle Edition.

Gear Talk

“Expose for the highlights” is a well-known rule of thumb in photography, that is, adjust the camera settings so the highlights are exposed perfectly.

Mature male Common Whitetail dragonflies are challenging to photograph because they prefer perching in direct sunlight, so it’s easy to blow out the highlights on their bright white abdomen. After a few test shots, I was able to adjust the flash power ratio so that the subject is exposed properly.

Copyright © 2019 Walter Sanford. All rights reserved.

Golden Boy

July 5, 2019

A Needham’s Skimmer dragonfly (Libellula needhami) was spotted at Occoquan Regional Park (ORP), Fairfax County, Virginia USA.

This individual is an immature male, as indicated by his coloration and terminal appendages. The yellowish-red coloration of this specimen could mislead you into thinking it’s a female. Be aware that the same species of dragonfly may appear differently depending upon gender, age, and natural variation.

At this stage in the male’s maturation, his coloration is similar to females of the same species. As a mature male, the front of his thorax and abdomen will be covered by red pruinescence.

Related Resource: Posts Tagged ‘Needham’s Skimmer dragonfly’

Copyright © 2019 Walter Sanford. All rights reserved.

Great Blue Skimmer dragonfly (mature male)

April 12, 2019

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 male, as indicated by his terminal appendages, discolored abdomen, and tattered wings.

This male has mated many times, as indicated by the scratches on his abdomen.

Males that have mated often have marks on their abdomen where the female legs have scratched them. This is especially obvious in species in which males develop pruinosity, as the pruinosity on the mid-abdomen is scratched off, and the signs are visible at some distance. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 390-392). Princeton University Press. Kindle Edition.

Copyright © 2019 Walter Sanford. All rights reserved.

Widow Skimmer dragonfly (immature male)

July 4, 2018

A Widow Skimmer dragonfly (Libellula luctuosa) was spotted during a photowalk at Occoquan Regional Park, Fairfax County, Virginia USA.

This individual is an immature male, as indicated by its coloration and terminal appendages. As a mature male, the front of his thorax and abdomen will be covered by white pruinescence.

Copyright © 2018 Walter Sanford. All rights reserved.

Survivors

May 25, 2018

The adult flight period for Blue Corporal dragonfly (Ladona deplanata) is from March 09 to July 09, according to records for the Commonwealth of Virginia maintained by Dr. Steve Roble; records for Northern Virginia maintained by Kevin Munroe show the flight period is from the second week in April to the first week in June. In my experience, the third week in May is late for Blue Corporal.

Meadowood Recreation Area

A single Blue Corporal dragonfly was spotted perched on the dock at Hidden Pond, Meadowood Recreation Area (MRA), Fairfax County, Virginia USA. This individual is a mature male, as indicated by his terminal appendages and dark blue pruinescence covering the body.

21 MAY 2018 | MRA | Blue Corporal (mature male)

Contrast the appearance of a mature male Blue Corporal with teneral males of the same species spotted on 26 April 2018 at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

21 MAY 2018 | MRA | Blue Corporal (mature male)

Prince William Forest Park

Two days later, another mature male Blue Corporal was spotted perched on the railing of an observation platform at a small pond located in Prince William Forest Park, Prince William County, Virginia USA.

23 MAY 2018 | MRA | Blue Corporal (mature male)

Editor’s Notes: Dr. Steve Roble is a zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage. Kevin Munroe is the former manager of Huntley Meadows Park, Fairfax County, Virginia.

Copyright © 2018 Walter Sanford. All rights reserved.

Blue Corporal (teneral males)

May 3, 2018

Several teneral male Blue Corporal dragonflies (Ladona deplanata) were spotted near Painted Turtle Pond during a photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

Teneral/immature/young male Blue Corporals look similar to females of the same species. Terminal appendages can be used to differentiate gender: males have three (3) appendages; females have two (2).

Some of the ground cover is charred from a recent controlled burn at Occoquan Bay NWR.

The common name for Blue Corporal is derived from two cream-colored stripes that appear on the front of the thorax, similar to the two stripes that signify the rank of corporal in the military. As a mature male, those stripes will be partially obscured by dark blue pruinescence.

Related Resource: Blue Corporal (teneral females).

Copyright © 2018 Walter Sanford. All rights reserved.

Widow Skimmers at Riverbend Park

February 25, 2017

A couple of Widow Skimmer dragonflies (Libellula luctuosa) were spotted while hunting for clubtail dragonflies along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. Riverbend Park is a “big river” habitat, so I was surprised to see Widow Skimmers.

Habitat Lakes, ponds, and pools in slow streams of all kinds with mud bottoms and usually much vegetation, in open and wooded habitats. Common at farm ponds and other created habitats. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 9061-9063). Princeton University Press. Kindle Edition.

Male

The first photo features a mature male, as indicated by his coloration, pattern of wing spots, and terminal appendages. This individual has mated many times, as shown by scratches on the white pruinescence covering his abdomen.

Female

A female is shown in the last two photos, as indicated by her coloration, pattern of wing spots, and terminal appendages.

Copyright © 2017 Walter Sanford. All rights reserved.

Sexing Common Green Darner dragonflies

October 30, 2016

Several field markers can be used to identify the gender of female and male Common Green Darner dragonflies (Anax junius).

Female

The following individual, spotted at Huntley Meadows Park, is a female. Female dragonflies have a pair of cerci (superior appendages) that have little or no function. The cerci (sing. cercus) of female Common Green Darners look like almonds, both in color and shape.

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

Two more field markers verify this specimen is female.

Note the brown stripe extending onto abdominal segment 2. Segment 2 [S2] is typically all pale on males. Also viewing at full resolution, the rear margin of the occiput is not straight. Females have blunt dark colored “teeth” back there which makes the margin look wavy. Source Credit: Ed Lam, author and illustrator of Damselflies of the Northeast, Northeast Odonata Facebook group.

Male

Male dragonflies have three terminal appendages, collectively called “claspers,” that are used to grab and hold female dragonflies during mating: an upper pair of cerci (“superior appendages”); and a lower unpaired epiproct (“inferior appendage”).

The cerci of male Common Green Darners are slightly darker in color and somewhat thicker and more rounded than the cerci of females of the same species. There are points at the tips of the two male cerci, as shown clearly in the full-size version of the following photo; female cerci are pointless, both literally and figuratively.

Male Common Green Darners have a very short epiproct that is used to grip the “teeth” on the back of head of females of the same species.

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

The individual in the preceding image is an immature male, as indicated by the purple coloration on his abdomen. As a mature male, his abdomen will be partially covered by blue pruinescence like the one shown below.

Related Resources: Digital Dragonflies, presenting high-resolution digital scans of living dragonflies.

  • Genus Anax | Anax junius | Common Green Darner | female | top view
  • Genus Anax | Anax junius | Common Green Darner | female | side view
  • Genus Anax | Anax junius | Common Green Darner | male | top view
  • Genus Anax | Anax junius | Common Green Darner | male | side view

Compare and contrast the cerci of female and male Common Green Darners by viewing the full-size versions of the preceding top views for both sexes and Ed Lam’s excellent composite image, shown below.

ed-lam_cgd_male-vs-female

Composite image used with permission from Ed Lam.

Copyright © 2016 Walter Sanford. All rights reserved.

Headfirst

October 22, 2016

Common Green Darner dragonfly (Anax junius) landed a few feet to my left as I was looking for Russet-tipped Clubtail dragonflies during a photowalk around Mulligan Pond at Jackson Miles Abbott Wetland Refuge (JMAWR).

Almost immediately, I realized the Common Green Darner was eating a smaller female Autumn Meadowhawk dragonfly (Sympetrum vicinum).

A Common Green Darner dragonfly (Anax junius) spotted at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This individual is a male, eating a female Autumn Meadowhawk dragonfly (Sympetrum vicinum).

16 OCT 2016 | JMAWR | Common Green Darner (male, eating prey)

Notice the Common Green Darner is eating the Autumn Meadowhawk headfirst, the fastest way for the predator to immobilize its prey.

A Common Green Darner dragonfly (Anax junius) spotted at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This individual is a male, eating a female Autumn Meadowhawk dragonfly (Sympetrum vicinum).

16 OCT 2016 | JMAWR | Common Green Darner (male, eating prey)

The Common Green Darner is an immature- to young male, as indicated by his coloration and terminal appendages. As a mature male, his abdomen will be partially covered by blue pruinescence.

A Common Green Darner dragonfly (Anax junius) spotted at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This individual is a male, eating a female Autumn Meadowhawk dragonfly (Sympetrum vicinum).

16 OCT 2016 | JMAWR | Common Green Darner (male, eating prey)

Copyright © 2016 Walter Sanford. All rights reserved.


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