Archive for January, 2015

Blue-faced Meadowhawk dragonflies (mating pair)

January 31, 2015

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) was spotted during a photowalk at Huntley Meadows Park on 12 October 2014. The pair was perched on the man-made berm that retains water in the 50-acre central wetland area.

The mating pair is “in wheel”: the male is on top; the female is on the bottom.

Blue-faced Meadowhawk dragonflies (mating pair, in wheel)

Female Blue-faced Meadowhawk dragonflies are polymorphic: heteromorphs are duller in color than males; andromorphs are male-like in color. The female in this mating pair is an andromorph, as indicated by her red coloration.

Blue-faced Meadowhawk dragonflies (mating pair, in wheel)

Polymorphs, heteromorphs, and andromorphs, oh my! You may be asking yourself, “How can I remember the difference between the words heteromorph and andromorph?” It’s easy.

The prefix “hetero-” means different; the prefix “andro-” means man. In biology, the base- or root word “morph” means variant forms of an animal or plant. Putting it all together, “heteromorph” means different form; “andromorph” means man-like form. So an andromorph female dragonfly, like the one featured in this post, is a form that looks like a male of the same species.

Remember this one-word mnemonic: heterosexual. Everyone knows heterosexuals prefer mating with members of the opposite sex. Logically it follows that female heteromorphs will look different from males. And if you know that obvious fact, then you can always remember what female andromorphs look like. Like I said, easy!

Copyright © 2015 Walter Sanford. All rights reserved.

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More Painted Skimmer dragonflies (males)

January 29, 2015

Several Painted Skimmer dragonflies (Libellula semifasciata) were spotted on 31 May 2014 near a vernal pool in a relatively remote location in the forest at Huntley Meadows Park.

Habitat: Boggy ponds and ditches with much emergent vegetation, usually associated with woodland. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 8999-9000). Princeton University Press. Kindle Edition.

These individuals are males, as indicated by their terminal appendages.

Painted Skimmer dragonfly (male)

Painted Skimmer dragonfly (male)

Painted Skimmer dragonfly (male)

Painted Skimmer dragonfly (male)

Painted Skimmer dragonfly (male)

Painted Skimmer dragonfly (male)

Painted Skimmer dragonflies are somewhat similar in appearance to Calico Pennant dragonflies (Celithemis elisa) and Halloween Pennant dragonflies (Celithemis eponina).

Notice the first two-thirds of the Painted Skimmer’s abdomen is translucent, revealing air spaces inside its body — a feature that clearly distinguishes Painted Skimmers from similar-looking dragonflies. Some experts think this adaptation provides thermal insulation that enables Painted Skimmer dragonflies to survive in colder climates.

Copyright © 2015 Walter Sanford. All rights reserved.

Another Great Spreadwing damselfly (male)

January 27, 2015

The following Great Spreadwing damselfly (Archilestes grandis) was spotted on 27 October 2014 near a vernal pool in the forest at Huntley Meadows Park. This individual is a male, as indicated by its coloration and terminal appendages.

Great Spreadwing damselfly (male)

Great Spreadwing damselfly (male)

Great Spreadwing damselfly (male)

Copyright © 2015 Walter Sanford. All rights reserved.

More color therapy

January 25, 2015

Several Great Spangled Fritillary butterflies (Speyeria cybele) were spotted at Huntley Meadows Park during photowalks in late-summer and early-fall 2014. The following photographs are shown in reverse chronological order.

Feeding on (a.k.a., nectaring) ironweed (Vernonia sp.) …

Great Spangled Fritillary butterfly (feeding on Ironweed)

12 September 2014

Feeding on climbing hempvine (Mikania scandens) …

Great Spangled Fritillary butterfly (feeding on climbing hempvine)

04 September 2014

Great Spangled Fritillary butterfly (feeding on climbing hempvine)

04 September 2014

Perching on a man-made brush shelter located near the berm that retains water in the 50-acre central wetland area

Great Spangled Fritillary butterfly (Speyeria cybele)

08 August 2014

Editor’s Note: Thanks to Matt Ryan, naturalist at Huntley Meadows Park, for help in identifying the climbing hempvine plant shown in the photos from 04 September 2014.

Copyright © 2015 Walter Sanford. All rights reserved.

Swamp Darner dragonfly (female, oviposition)

January 23, 2015

The following photos show a Swamp Darner dragonfly (Epiaeschna heros) spotted on 23 May 2014 near a vernal pool in a relatively remote location in the forest at Huntley Meadows Park. This individual is a female, shown laying eggs (oviposition) in a muddy drainage ditch.

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 all of the following photos.

Swamp Darner dragonfly (female, oviposition)

Swamp Darner dragonfly (female, oviposition)

Swamp Darner dragonfly (female, oviposition)

Swamp Darner dragonfly (female, oviposition)

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

  • Genus Epiaeschna | Epiaeschna heros | Swamp Darner | female | top view
  • Genus Epiaeschna | Epiaeschna heros | Swamp Darner | female | side view

See also Swamp Darner Ovipositing in Rotting Log (NJ, USA), an excellent YouTube video published on June 5, 2014, shot from the edge of a vernal pool located in New Jersey.

Copyright © 2015 Walter Sanford. All rights reserved.

Winter blues…

January 21, 2015

A panoply of Painted Skimmer dragonflies (Libellula semifasciata) provides a palette of oranges, reds, and yellows that brightens the dreary days of mid-winter.

Males

Painted Skimmer dragonfly (male)

Painted Skimmer dragonfly (male)

Painted Skimmer dragonfly (male)

Painted Skimmer dragonfly (male)

Painted Skimmer dragonfly (male)

Females

Painted Skimmer dragonfly (female)

Painted Skimmer dragonfly (female)

All of the preceding individuals were spotted on 02 June 2014 near a vernal pool in a relatively remote location in the forest at Huntley Meadows Park.

Painted Skimmer dragonflies do not display sexual dimorphism, that is, males and females are nearly identical in appearance except for their terminal appendages. Also notice the faces of male Painted Skimmers are white and red, like their faces are “sunburned”; female faces are white and tan.

Copyright © 2015 Walter Sanford. All rights reserved.

Parasitic gall wasps

January 19, 2015

Where it all began

Unknown insect gall

06 November 2013

During a photowalk at Huntley Meadows Park on 06 November 2013, I spotted an unusual growth on a branch of a Swamp Rose (Rosa palustris) plant. I spent several weeks during Fall 2013 carefully searching the same spot for Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) but never noticed the potato-like growth until after most of the leaves had fallen from the plant.

Turns out the growth is a gall caused by a parasitic wasp. Charley Eiseman, widely regarded as the go-to gall guy, said “It is likely a Diplolepis sp. gall.” Diplolepis is a genus of gall wasp in the Family Cynipidae.

Charley also said the only way to make a positive identification would be to collect a few galls in the hope of capturing some wasps when they emerged from the galls. In the interest of science, Kevin Munroe, manager at Huntley Meadows Park, kindly granted one-time permission for me to collect a few galls.

Waiting and watching

On 11 March 2014, three (3) insect galls — similar to one I photographed during Fall 2013 — were collected from Swamp Rose (Rosa palustris) plants located alongside the boardwalk in the hemi-marsh at Huntley Meadows Park. The largest gall was ~1.9 cm (~3/4 in) long. There was one small hole in the gall when it was collected; there were no holes in the other two galls.

The galls were stored indoors in a sealed Ziploc plastic bag for several weeks. I checked daily to see whether anything had emerged. At least once, moisture was wiped from inside the bag in order to prevent the galls from getting moldy.

Parasitic insect galls and gall wasps

04 April 2014

The following photograph is shown for scale: the insect galls (and later, tiny gall wasps) were stored in a Johnson Ziploc XL Sandwich bag; its dimensions are 7 in x 8 in (17.7 cm x 20.3 cm). I taped the plastic bag to the window of my apartment at the Beacon of Groveton in order to shoot still photos and video before sending the specimens to Charley Eiseman.

Parasitic insect galls and gall wasps

04 April 2014

Gall wasps began emerging from the galls on 03 April 2014. The preceding photos were shot on 04 April 2014, and the following movie was recorded on the same day. Individual specimens are ~2 mm (1/16 in) long.

Tech Tip: The preceding video looks better viewed in full-screen mode.

A closer look at what emerged from the galls

Charley Eiseman used a Canon EOS Rebel XSi, MP-E 65mm lens, and MT-24EX Twin Lite flash to shoot the following excellent macro photographs on 08 April 2014.

The first photo shows a gall wasp (~2.2 mm long) that was covered with “crumbs” from chewing its way out of the gall.

IMG_6564

Photo used with permission from Charley Eiseman.

Charley shared another photo of a later-emerging, cleaner-looking gall wasp (~2.2 mm long).

IMG_6686

Photo used with permission from Charley Eiseman.

One parasitoid, shown below, emerged among tens of gall wasps: Eupelmus dryohizoxeni (female), 3 mm long. That’s right, this parasitoid feeds on the gall wasps that parasitize Swamp Rose — now there’s an interesting and unusual food chain!

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Photo used with permission from Charley Eiseman.

Where do we go from here?

The gall wasps collected at Huntley Meadows Park don’t seem to match any species in the scientific literature, so Charley Eiseman sent some specimens to an entomologist who specializes in micro-wasps. We are waiting patiently for the specialist to identify the species.

Related Resources:

Editor’s Notes: Sincere thanks to Kevin Munroe for facilitating my amateur scientific investigation, and to Charley Eiseman for his extraordinary kindness in helping a virtual stranger!

Copyright © 2015 Walter Sanford. All rights reserved.

Blue-faced Meadowhawk dragonflies (mating pairs, in wheel)

January 17, 2015

The following photographs show two mating pairs of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted on 17 October 2014 near a vernal pool in the forest at Huntley Meadows Park.

Both pairs are “in wheel”: the males are on top; the females are on the bottom. Both females are heteromorphs, as indicated by their coloration.

Blue-faced Meadowhawk dragonflies (mating pair, in wheel)

Mating Pair No. 1

Copulation between the male (S2-3) and female (S8) abdominal segments is shown clearly in preceding uncropped photo.

Blue-faced Meadowhawk dragonflies (mating pair, in wheel)

Mating Pair No. 2

Copyright © 2015 Walter Sanford. All rights reserved.

Crayfish

January 15, 2015

Crayfish

Two types of crayfish are known to inhabit the waters at Huntley Meadows Park: a native species; and a non-native species.

We believe our native species is Cambarus diogenes [known as “chimney crayfish”], although we’re not positive about the species. Source Credit: Mr. Kevin Munroe, Park Manager at Huntley Meadows.

The non-native species is “red swamp crayfish” (Procambarus clarkii), according to Ms. Kat Dyer, a long-time volunteer at Huntley Meadows Park also known as the “Crayfish Lady.” Ms. Dyer is now a part-time naturalist at the park.

The crayfish, shown above, was spotted alongside the boardwalk in the hemi-marsh at Huntley Meadows on 24 August 2014. I consulted the local experts for help in identifying the species.

Crayfish are just real hard to ID! You have to have a mature male, and you need to look at the tiny appendages under the abdomen to make a positive ID. My guess is that it’s the [non-native] exotic species since you found it in the wetland rather than in the streams/woods. Source Credit: Kevin Munroe, Park Manager at Huntley Meadows.

Crayfish is an important organism in the wetlands ecosystem food web. Many animals prey upon crayfish, including fish, raccoons, otters, Great Blue Herons, and Great Egrets. Brush shelters (that resemble large, man-made beaver lodges) located in the 50-acre central wetland area provide egg-laying habitat for crayfish.

Copyright © 2015 Walter Sanford. All rights reserved.

Wheel of life

January 13, 2015

The wheel of life goes round and round…

Autumn Meadowhawk dragonflies (mating pair, in wheel)

The preceding photograph shows a mating pair of Autumn Meadowhawk dragonflies (Sympetrum vicinum) spotted on 27 October 2014 near a vernal pool in the forest at Huntley Meadows Park. The pair is shown “in wheel.”

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.

All dragonflies and damselflies have a 10-segmented abdomen: male dragonfly secondary genitalia are located in segments two and three (2 and 3); female genitalia in segment eight (8). Therefore, the male dragonfly is on top; the female is on the bottom.

Copyright © 2015 Walter Sanford. All rights reserved.


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