Archive for May, 2016

Miraculous metamorphosis

May 11, 2016

I was sitting on my Coleman camp stool on the earthen dam at Hidden Pond, Meadowood Recreation Area, hoping the sky would clear so I could see some odonates. The sky was almost completely overcast; as a result, I hadn’t seen any dragonflies or damselflies all morning.

My cell phone rang. Matt Ryan, a good friend and part-time naturalist at Huntley Meadows Park, called to tell me about a dragonfly larva he spotted that had just started to transform into an adult. I was conflicted for a few minutes: Meadowood Recreation Area is much farther from my home than Huntley Meadows Park so I was reluctant to leave empty-handed, so to speak, especially since several species of odonates can be seen at Meadowood that aren’t known to occur at Huntley. Fortunately I came to my senses and drove to Huntley as quickly as possible.

The following photo is the first image from a three-hour time-series documenting an emergent female Common Whitetail dragonfly (Plathemis lydia), located within a few feet from the boardwalk in the central wetland area at Huntley Meadows Park. The miraculous metamorphosis was well underway by the time I arrived at the spot. Elapsed time is expressed in hh:mm:ss format.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 11:21 am EDT | Elapsed time: 00:00:00

The wings, folded like accordions, then begin to fill from the base with fluid transferred from the body and fairly soon reach full length. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 466-467). Princeton University Press. Kindle Edition.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 11:32 am EDT | Elapsed time: ~00:11:00

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 12:20 pm EDT | Elapsed time: ~00:59:00

The fluid is then pumped back into the abdomen, and it expands. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 467-468). Princeton University Press. Kindle Edition.

Notice the wings are nearly clear in following photo, indicating the greenish-colored fluid that formerly filled the wings is almost gone. The abdomen is noticeably longer in this photo than in the first image in the time-series, taken at 11:21 EDT.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 12:43 pm EDT | Elapsed time: ~01:22:00

At this point, a pair of terminal appendages (cerci) was clearly visible at the end of the abdomen, indicating this individual is a female.

Notice the wing spots are beginning to darken. A pattern of dark spots on all four wings, characteristic of female Common Whitetail dragonflies, will develop within a few days to a week-or-so after emergence.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 01:23 pm EDT | Elapsed time: ~02:02:00

Finally, the wings open up, and very soon the teneral adult flies away. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 468). Princeton University Press. Kindle Edition.

The pair of wings on her right side snapped into the resting position approximately two hours and 18 minutes (~02:18:00) after I started this time-series of photos.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 01:38:42 pm EDT | Elapsed time: 02:17:42

The pair of wings on her left side snapped into the resting position one minute and four seconds (00:01:04) later.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 01:39:46 pm EDT | Elapsed time: 02:18:46

Her wings quivered slightly at ~02:24:00 pm and then she flew away.

A Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is an emerging female.

07 MAY 2016 | 02:24 pm EDT | Elapsed time: ~03:03:00

The last photo shows the cast skin from the emergent dragonfly, technically known as an exuvia (singular).

A cast skin from a Common Whitetail dragonfly spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This is the exuvia of an emerging female.

07 MAY 2016 | 02:28 pm EDT | Elapsed time: ~03:07:00

Although I have seen two emerging dragonflies from a different family, albeit briefly, and seen several exuviae (plural) in situ, this was my first opportunity to observe the process carefully for several hours. Sincere thanks to Matt Ryan for kindly thinking of me!

Copyright © 2016 Walter Sanford. All rights reserved.

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Another female Stream Cruiser?

May 9, 2016

It’s possible the female Stream Cruiser dragonfly (Didymops transversa) in this gallery — spotted on 20 April 2016 at Accotink Bay Wildlife Refuge — is the same individual featured in a photoblog post published on 23 April 2016.

A Stream Cruiser dragonfly (Didymops transversa) spotted at Accotink Bay Wildlife Refuge, Fairfax County, Virginia USA. This individual is a female.

This is the second photo set that I shot of female Stream Cruisers spotted along the same segment of Beaver Pond Loop Trail. Although the two female dragonflies were perching on opposite sides of the trail, this female could be the same one that I spooked a few minutes earlier when I moved too close for her comfort.

A Stream Cruiser dragonfly (Didymops transversa) spotted at Accotink Bay Wildlife Refuge, Fairfax County, Virginia USA. This individual is a female.

This individual is a female as indicated by the pair of white terminal appendages (cerci) at the end of her abdomen, clearly visible in the following photo.

A Stream Cruiser dragonfly (Didymops transversa) spotted at Accotink Bay Wildlife Refuge, Fairfax County, Virginia USA. This individual is a female.

Stream Cruiser dragonflies have extremely long legs, especially noticeable in the last photo. The abdomen of female Stream Cruisers is thicker than males of the same species, similar to many species of odonates.

A Stream Cruiser dragonfly (Didymops transversa) spotted at Accotink Bay Wildlife Refuge, Fairfax County, Virginia USA. This individual is a female.

Copyright © 2016 Walter Sanford. All rights reserved.

Forest Tent Caterpillar Moth

May 7, 2016

A Forest Tent Caterpillar Moth (Malacosoma disstria) spotted at Huntley Meadows Park, Fairfax County, Virginia USA.

Behold the subtle beauty of a Forest Tent Caterpillar Moth (Malacosoma disstria) caterpillar, spotted on 24 April 2016 in the forest at Huntley Meadows Park. As an adult moth, this species looks relatively plain.

Forest Tent Caterpillar Moth caterpillars look similar to Eastern Tent Caterpillar Moth (Malacosoma americana) caterpillars. As I’m fond of saying, similar is not the same: the “dorsum of each abdominal segment has distinct whitish keyhole or shoeprint-shaped marking” on Forest Tent Caterpillars; Eastern Tent Caterpillars are “distinguished by a solid cream/white line along the dorsum (middle of the back).”

Copyright © 2016 Walter Sanford. All rights reserved.

Spicebush Swallowtail butterfly

May 5, 2016

In my experience, Spicebush Swallowtail butterflies (Papilio troilus) tend to be hyperactive: they flit around randomly, almost non-stop; when they land it is usually only briefly.

A Spicebush Swallowtail butterfly (Papilio troilus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA.

A Spicebush Swallowtail was spotted on 24 April 2016 in the forest at Huntley Meadows Park.

A Spicebush Swallowtail butterfly (Papilio troilus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA.

This one seemed to be a little more sluggish than usual on a cool spring morning, giving me an opportunity to shoot some of the better photos I’ve taken of a Spicebush Swallowtail butterfly.

A Spicebush Swallowtail butterfly (Papilio troilus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA.

Copyright © 2016 Walter Sanford. All rights reserved.

Gomphidae exuvia

May 3, 2016

A dragonfly exuvia was spotted by a friend at an unknown location in Northern Virginia. This specimen is a member of the Family Gomphidae (Clubtails). Here’s the decision tree I used to tentatively identify the exuvia as a member of the Clubtail Family.

  • The specimen has a flat labium (not mask-like).
  • Antennae are club-like (not thin and thread-like, as in Aeshnidae).
  • Eyes not exceptionally large compared to the size of the head (not large, as in Aeshnidae).

Gomphidae is the second largest family of dragonflies, so it could be challenging to identify this specimen to the genus and species level.

Photo Set 1

A dragonfly exuvia spotted at an unknown location in Northern Virginia. This specimen may be a member of the Family Gomphidae (Clubtails).

Head-on view, ventral side up.

Notice the labium isn’t mask-like, that is, doesn’t cover the face of the larva/exuvia.

A dragonfly exuvia spotted at an unknown location in Northern Virginia. This specimen may be a member of the Family Gomphidae (Clubtails).

Head-on view, rotated 180°.

A dragonfly exuvia spotted at an unknown location in Northern Virginia. This specimen may be a member of the Family Gomphidae (Clubtails).

Anal pyramid view, ventral side up.

A dragonfly exuvia spotted at an unknown location in Northern Virginia. This specimen may be a member of the Family Gomphidae (Clubtails).

Head-on view, dorsal side up.

A dragonfly exuvia spotted at an unknown location in Northern Virginia. This specimen may be a member of the Family Gomphidae (Clubtails).

Lateral view, right side (facing forward).

A dragonfly exuvia spotted at an unknown location in Northern Virginia. This specimen may be a member of the Family Gomphidae (Clubtails).

Lateral view, left side (facing forward).

Photo Set 2

A dragonfly exuvia spotted at an unknown location in Northern Virginia. This specimen may be a member of the Family Gomphidae (Clubtails).

Dorsal view.

A dragonfly exuvia spotted at an unknown location in Northern Virginia. This specimen may be a member of the Family Gomphidae (Clubtails).

Ventral view.

Photo Set 3

Gomphidae-exuvia_focus-stack_Ver3

Composite image.

The preceding composite image is a stack of 11 focus layers, moving from front-to-back across the face and head of the exuvia. Notice the labium isn’t mask-like, that is, doesn’t cover the face of the larva/exuvia. Also notice both antennae are club-like and most of the right antenna (facing forward) is missing.

Photo Set 4

The following macro photo shows a close-up of the face and head of the exuvia. The photo clearly shows the flat labium doesn’t cover any part of the face. Look closely at the full-size version of this image and you will notice two movable hooks at the front of the labium (see annotated illustration); they are reddish in color and the one on the left (relative to the photo) is more clearly in focus than the one on the right.

A dragonfly exuvia spotted at an unknown location in Northern Virginia. This specimen may be a member of the Family Gomphidae (Clubtails).

24x magnification.

Most, but not all, species of Gomphidae larvae are burrowers. The specimen is noticeably dirty — perhaps that indicates this individual is a burrowing species of clubtail dragonfly.

Related Resources

Tech Tips

The following equipment was used to shoot the preceding photographs:

Adobe Photoshop CC 2015 was used for minor touch-up work on the background of all photos.

Copyright © 2016 Walter Sanford. All rights reserved.

Spring Peeper

May 1, 2016

Michael Powell and I were searching for the elusive Springtime Darner dragonfly (Basiaeschna janata) during a photowalk at Huntley Meadows Park on 15 April 2016. (By the way, we found one later the same day!)

As we were walking along a thorny thicket of greenbrier (Smilax sp.), I noticed a frog-let/toad-let — my term for small frogs and toads that are seen commonly in the wetlands at the park, especially during spring. The individual shown in the following photos is an inch or less in length!

My first thought is usually, “Oh, it’s just a frog-/toad-let. Nothing to see here. Move along.” Good thing I decided to take a closer look. Turns out the frog-/toad-let is a Spring Peeper (Pseudacris crucifer), as indicated by the dark “X” on the frog’s dorsal side.

A Spring Peeper (Pseudacris crucifer) spotted at Huntley Meadows Park, Fairfax County, Virginia USA.

These photos were years in the making. Huh? I have been a frequent visitor at Huntley Meadows Park for over 30 years. Every spring, the sound of male Spring Peepers calling for mates is deafening. You hear them, but you never see them, that is, until this year when I spotted my first ever Spring Peeper!

A Spring Peeper (Pseudacris crucifer) spotted at Huntley Meadows Park, Fairfax County, Virginia USA.

I spotted the first peeper; Mike spotted a second peeper while we were photographing the first one. The peeper shown in this photo set is actually the second one we saw; photos of the first peeper will be published in a follow-up post.

Related Resource: Spring Peeper, by Mike Powell.

Copyright © 2016 Walter Sanford. All rights reserved.


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