Archive for September, 2014

Another first!

September 29, 2014

I was delighted to find my first male Slender Spreadwing damselfly (Lestes rectangularis) during a photowalk at Huntley Meadows Park on Sunday, 28 September 2014.

Slender Spreadwing damselfly (male)

Slender Spreadwing damselfly (male)

The Backstory: I added the following post to the Northeast Odonata Facebook group on Saturday, 27 September 2014.

There are two species of spreadwing damselflies on the Friends of Huntley Meadows Park Dragonflies and Damselflies species list: Slender Spreadwing; and Swamp Spreadwing. I have seen and/or photographed lots of Slender Spreadwing damselflies at the park; oddly, EVERY ONE was female! Really, what are the odds I would NEVER see a Slender Spreadwing male? Should I look for males in a particular place? And I have NEVER seen a Swamp Spreadwing, neither male nor female! Again, what are the odds? HMP features a HUGE wetland area including a long boardwalk that makes much of the marshland easy to access. Same question regarding Swamp Spreadwings — is there a particular place where I should look for them?

My post received one reply. One reply provided all the information I needed.

In my experience, Swamp Spreadwings are easier to find early in the day, like around two- or three hours after sunrise. Slender Spreadwing males should be around, but skulking kind of low, maybe away from the water like in brush. Source Credit: SueandJohnKestrelHaven.

Many odonates are habitat-specific; they are easier to find when you know where to look. Turns out I’ve been looking in the wrong place for male Slender Spreadwing damselflies. On the strength of good advice from Sue, I found one more quickly than expected. Thanks, Sue!

Now, if I can just get up and out the door early enough to test Sue’s advice regarding where and when to find Swamp Spreadwing damselflies (Lestes vigilax), then I might get lucky again!

Copyright © 2014 Walter Sanford. All rights reserved.

May I have the next dance?

September 27, 2014

Clip-wing Grasshoppers (mating pair)

Here’s something you don’t see everyday: a mating pair of Clip-wing Grasshoppers (Metaleptea brevicornis), also known as Silent Slant-faced Grasshoppers. The male is on top; the female on the bottom.

The individual shown on the right is probably a male Short-winged Green Grasshopper (Dichromorpha viridis).

Thanks to the following members of the BugGuide Facebook group for their kind assistance in identifying the grasshoppers shown in the preceding photo: Michael Jared Thomas; Dan Johnson; and Eric Eaton.

Copyright © 2014 Walter Sanford. All rights reserved.

Wandering Glider dragonfly (male)

September 25, 2014

The following photographs show a Wandering Glider dragonfly (Pantala flavescens) spotted near the end of the boardwalk at Huntley Meadows Park on 23 September 2014. This individual is a male, based upon the following description.

Male: Eyes reddish; face orange. Thorax and abdomen yellow, upper part of abdomen orange. Darker orange median line on abdomen, expanded on each segment and forming black spots toward rear, on S8–10. Cerci black, obviously pale at base. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 11282-11283). Princeton University Press. Kindle Edition.

Remember that “S8-10″ refers to abdominal segments eight through 10 (of 10), numbered from front to back.

It is uncommon to see the broad-winged skimmers from the genus Pantala perching. Dragonflies are classified as either “fliers” or “perchers,” based upon their feeding habits. Wandering Gliders are fliers. I was fortunate to be able to “work the shot” when this guy landed for a long rest during the afternoon!

Wandering Glider dragonfly (male)

Wandering Glider dragonfly (male)

Wandering Glider dragonfly (male)

Wandering Glider dragonfly (male)

Wandering Glider dragonfly (male)

Wandering Glider dragonfly (male)

Wandering Glider is one of at least five major species of dragonflies known to be migratory in North America. One field marker most migratory dragonflies have in common: broad hindwings.

The very broad hindwings represent an important adaptation for gliding, … Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 11276-11277). Princeton University Press. Kindle Edition.

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

  • Genus Pantala | Pantala flavescens | Wandering Glider | male | top view
  • Genus Pantala | Pantala flavescens | Wandering Glider | male | side view
  • Genus Pantala | Pantala flavescens | Wandering Glider | female | top view
  • Genus Pantala | Pantala flavescens | Wandering Glider | female | side view

See interactive three-dimensional (3-D) virtual imagery of the five migratory dragonflies, including Wandering Glider, provided by the Migratory Dragonfly Partnership.

Copyright © 2014 Walter Sanford. All rights reserved.

New species of dragonfly spotted at Huntley Meadows Park!

September 23, 2014

I discovered a new species of dragonfly during a photowalk along the boardwalk in the central wetland area at Huntley Meadows Park on 17 September 2014. I named it “Black Dasher.” (“Slaty Dasher” is under consideration as an alternate common name.)

But seriously, I have never seen a male Blue Dasher dragonfly (Pachydiplax longipennis) colored like this one!

Blue Dasher dragonfly (male, unusual coloration)

From the wear on the wings, he looks quite mature so either the usual pruinosity never developed or it has come off somehow. I’ve seen wear from matings and age but never this much and not so uniform. Very unusual. Source Credit: Ed Lam, author and illustrator of Damselflies of the Northeast.

Blue Dasher dragonfly (male, unusual coloration)

Contrast the coloration of the “Black/Slaty Dasher” (shown above) with another male Blue Dasher (shown below), photographed using the same equipment on the same day at the same place. Notice the abdomen of the following individual is covered by blue pruinescence, typical of adult male Blue Dashers.

Blue Dasher dragonfly (male)

No wonder the first step in “Five steps to the next level of dragonfly spotting” says …

Step 1. Be aware the same species of dragonfly may appear differently depending upon gender, age, and natural variation. Some species display sexual dimorphism; in contrast, both genders look virtually identical for some species. Source Credit: Walter Sanford. Educator, Naturalist, and Photographer.

Copyright © 2014 Walter Sanford. All rights reserved.

Northern Rough Greensnake

September 21, 2014

The Northern Rough Greensnake (Opheodrys aestivus), shown below, was one of my “great white whales.” That is, until my luck changed recently. Eureka!

It is usually found in areas of thick, green vegetation. Small trees, bushes, briar patches, and tangles of vines are favorite areas. … This is the only arboreal snake in Virginia. … This species eats mainly grasshoppers, crickets, caterpillars, spiders, small frogs, and snails or slugs. Source Credit: Northern Rough Greensnake (Opheodrys aestivus aestivus), Virginia Department of Game and Inland Fisheries.

Northern Rough Greensnake (Opheodrys aestivus)

The greensnake was spotted during a photowalk along the boardwalk in the central wetland area at Huntley Meadows Park on 19 September 2014. I estimate this individual is approximately three feet (3′) in length.

Northern Rough Greensnake (Opheodrys aestivus)

Some snakes tend to freeze and remain motionless when confronted by danger. As soon as the snake saw me, it froze in place just long enough for me to take a few photos. The greensnake slithered into dense vegetation alongside the boardwalk and disappeared quickly after a couple of hikers walked around the snake.

Copyright © 2014 Walter Sanford. All rights reserved.

The real monsters of Huntley Meadows

September 19, 2014

Longtime residents of eastern Fairfax County, Virginia USA may recall reading about the “Mount Vernon Monster” that reportedly roamed the region during the late 1970s. Although I have neither seen nor heard the monster, I jokingly reply “Bigfoot” whenever people pass me at Huntley Meadows Park and ask whether I shot any good photographs. But seriously, folks — there are real monsters at the park, including horse flies and robber flies.

The following photos show two horse flies, possibly Tabanus calens, spotted during recent photowalks along the boardwalk in the central wetland area. Both individuals are females. Male horse flies don’t bite; females bite, painfully!

Adult horse flies feed on nectar and sometimes pollen. Females of most species are anautogenous, meaning they require a blood meal before they are able to reproduce effectively, if at all. Much like male mosquitoes, male Tabanidae are not ectoparasitic and lack the mouth parts (mandibles) that the females use in drawing the blood on which they feed. Most female horse flies feed on mammalian blood, but some species are known to feed on birds or reptiles. Some are said to attack amphibians as well. Source Credit: Horse-fly, from Wikipedia.

Horse fly (female)

17 September 2014. Photo 1. Horse fly (female).

Males have eyes that meet along a seam down the middle of the head (holoptic eyes); females have eyes that are well-separated. Source Credit: Benjamin A. Coulter, member of the BugGuide group on Facebook.

Horse fly (female)

17 September 2014. Photo 2. Horse fly (female).

The next gallery shows another female horse fly spotted along the boardwalk on 15 September 2014.

The last photo shows a Red-footed Cannibalfly (Promachus rufipes), a species of robber fly spotted near the beginning of the boardwalk.

Red-footed Cannibalfly (Promachus rufipes)

10 September 2014. Red-footed Cannibalfly (female).

Robber flies feed mainly on other insects. (Whew, that’s a relief!)

The fly attacks its prey by stabbing it with its short, strong proboscis injecting the victim with saliva containing neurotoxic and proteolytic enzymes which very rapidly paralyze the victim and soon digest the insides; the fly then sucks the liquefied material through the proboscis. Source Credit: Asilidae, from Wikipedia.

There are “approximately 1,040 species of robber flies in approximately 100 genera in our area.” Source Credit: Family Asilidae – Robber Flies, from BugGuide. Thanks to Mike Powell, fellow wildlife photographer and blogger, for identifying the species of robber fly shown above!

Copyright © 2014 Walter Sanford. All rights reserved.

Slaty Skimmer dragonfly (mature male)

September 17, 2014

Another photograph from my “Simply Slaty” series …

Slaty Skimmer dragonfly (mature male)

The preceding photo shows a Slaty Skimmer dragonfly (Libellula incesta) spotted in the hemi-marsh at Huntley Meadows Park on 10 September 2014. This individual is a mature male, as indicated by its coloration, terminal appendages, and tattered wings.

Copyright © 2014 Walter Sanford. All rights reserved.

The Bronze Age

September 15, 2014

The following photograph shows a Great Blue Skimmer dragonfly (Libellula vibrans) spotted during a photowalk along the boardwalk in the central wetland area at Huntley Meadows Park on 12 September 2014. This individual is an old female, as indicated by its coloration, terminal appendages, and tattered wings.

Female Great Blue Skimmers have a pair of flanges beneath their eighth abdominal segment that are used to scoop and hold a few drops of water when laying eggs (oviposition), hence the family name “Skimmer.” Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.

Great Blue Skimmer dragonfly (mature adult female)

Contrast the coloration of the old female (above) with a young female (below), shown in flight as she is laying eggs (oviposition) in a vernal pool in the forest. The photo was taken on 17 July 2014.

Great Blue Skimmer dragonfly (female, oviposition)

No wonder the first step in “Five steps to the next level of dragonfly spotting” says …

Step 1. Be aware the same species of dragonfly may appear differently depending upon gender, age, and natural variation. Some species display sexual dimorphism; in contrast, both genders look virtually identical for some species. Source Credit: Walter Sanford. Educator, Naturalist, and Photographer.

Copyright © 2014 Walter Sanford. All rights reserved.

Handsome Meadow Katydids (mating pair)

September 13, 2014

Handsome Meadow Katydids (mating pair)

The preceding photograph shows a mating pair of Handsome Meadow Katydids (Orchelimum pulchellum) spotted during a a photowalk along the boardwalk in the central wetland area at Huntley Meadows Park on 10 September 2014.

Can you tell which member of the mating pair is the male and which one is the female? Hint: There is at least one obvious difference between the two individuals.

Handsome Meadow Katydid (female)

Look closely at the preceding photo, taken at Huntley Meadows on 12 September 2014. Did you notice the long, curved, reddish-colored structure extending from the posterior end of the abdomen? It’s an ovipositor that female katydids …

… use to insert eggs into hiding places (which can be in crevices on plants or even inside plant tissues). Source Credit: Matt Pelikan, BugGuide group on Facebook.

The following photo was shot at Huntley Meadows on 10 September 2014. This individual is a male, as indicated by the absence of an ovipositor.

The wings pretty much obscure the most visible male parts, but these also have distinctive shapes in katydids and are useful for ID. Source Credit: Matt Pelikan, BugGuide group on Facebook.

Handsome Meadow Katydid (male)

Coming full circle to the mating pair of Handsome Meadow Katydids shown in the first photo, the female is on top and the male is on the bottom.

Copyright © 2014 Walter Sanford. All rights reserved.

Blue Dasher dragonfly (adult female, oviposition, in flight)

September 11, 2014

Blue Dasher dragonfly (female, oviposition, in flight)

The photographs in this post show a Blue Dasher dragonfly (Pachydiplax longipennis) spotted during a photowalk along the boardwalk in the central wetland area at Huntley Meadows Park on 24 August 2014. This individual is an adult female, as indicated by its coloration and terminal appendages, shown in flight as she is laying eggs (oviposition) in the hemi-marsh.

Blue Dasher dragonfly (female, oviposition, in flight)

Editor’s Note: I used a Canon 580EX II Speedlite mounted on my Panasonic Lumix DMC-FZ150 superzoom digital camera — it works much better than the built-in pop-up flash! The external flash unit works in manual mode only. For more information, see Lessons Learned: How to use a superzoom camera to shoot insect photos.

Copyright © 2014 Walter Sanford. All rights reserved.