Posts Tagged ‘ovipositor’

MYN – Tramea carolina exuvia (ventral)

January 20, 2020

Carolina Saddlebags dragonfly (Tramea carolinaexuvia was collected by Andy Davidson near Richmond, Virginia USA. Carolina Saddlebags is a member of Family Libellulidae (Skimmers).

This individual might be a female, as indicated by what appears to be a small rudimentary ovipositor located along the margin between abdominal segments eight and nine (S8-9).

Related Resources

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Hagenius brevistylus exuvia (ventral)

January 6, 2020

An odonate exuvia was photographed against a pure white background using the “Meet Your Neighbours” (MYN) technique.

This specimen is a Dragonhunter dragonfly (Hagenius brevistylus) exuvia. Dragonhunter is a member of Family Gomphidae (Clubtails).

Dorsal view update

I’ve made the same mistake twice recently: When in doubt, the “model” should face the camera! In my opinion, the following updated photo looks better than the version that shows the model facing away from the camera (published in my last blog post).

Ventral view

This individual is a female, as indicated by the rudimentary ovipositor located along the boundary between abdominal segments eight and nine (S8-9).

Related Resources

Tech Tips

The first two photos were taken using the same MYN Field Studio setup described in detail in my last blog post.

The last photo was taken by swapping the Godox TT685F fill flash for my Canon MT-26EX-RT Macro Twin Lite. The Canon flash was set for a power ratio of 1/32.

Copyright © 2020 Walter Sanford. All rights reserved.

Another Arrowhead Spiketail (female)

June 21, 2019

An Arrowhead Spiketail dragonfly (Cordulegaster obliqua) was spotted in a sunny clearing along a small-to-medium size forest stream at an undisclosed location in Prince William County, Virginia USA.

14 JUN 2019 | PNC. William County, VA | Arrowhead Spiketail (female)

This individual is a female, as indicated by her rounded hind wings, terminal appendages, and prominent ovipositor at the tip of her abdomen.

14 JUN 2019 | PNC. William County, VA | Arrowhead Spiketail (female)

Did you recognize the interrupted fern (Osmunda claytoniana) in the background of every photo in this gallery?

14 JUN 2019 | PNC. William County, VA | Arrowhead Spiketail (female)

The Backstory

Mike Powell and I stopped to use GPS to get a fix on our position at the end of a long photowalk that included lots of bushwhacking. We stopped because the small stream we were exploring was getting wider and deeper the farther we walked downstream, and we decided the stream habitat had changed to be less suitable for Sable Clubtail (S. rogersi), our target species.

The place where we stopped is a sunny meadow near the confluence of a tiny side stream with the larger stream we were following. As Mike was testing a few GPS apps for his Android cell phone, I noticed a big dragonfly as it flew down the tiny stream, turned left past us, and landed in the sunny meadow. I found the dragonfly after a few minutes of searching the area where I saw it land. I was hoping for a Tiger Spiketail (Cordulegaster erronea) but nonetheless delighted to see a female Arrowhead Spiketail — our second record of this species for the year at the remote location!

Related Resource: Arrowhead Spiketail dragonfly (female)

Copyright © 2019 Walter Sanford. All rights reserved.

Arrowhead Spiketail dragonfly (female)

May 27, 2019

An Arrowhead Spiketail dragonfly (Cordulegaster obliqua) was spotted in a sunny clearing along a small forest stream at an undisclosed location in Prince William County, Virginia USA.

21 MAY 2019 | PNC. William County, VA | Arrowhead Spiketail (female)

This individual is a female, as indicated by her rounded hind wings, terminal appendages, and prominent ovipositor at the tip of her abdomen.

[Females in the Family Cordulegastridae (Spiketails) feature a] …pointed and spikelike (thus the group name) ovipositor, really a “pseudo-ovipositor” formed from the prolonged subgenital plate. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 7005-7006). Princeton University Press. Kindle Edition.

21 MAY 2019 | PNC. William County, VA | Arrowhead Spiketail (female)

Although the pattern of arrowhead-shaped markings visible on the dorsal side of her abdomen is unmistakeable, notice that the thorax features two stripes. The latter field mark can be used to differentiate spiketails from cruisers that have one stripe on their thorax.

21 MAY 2019 | PNC. William County, VA | Arrowhead Spiketail (female)

Mike Powell and I have photowalked together so many times that we are comfortable working cooperatively to shoot a subject. I wanted to get a shot of the face of the Arrowhead Spiketail but was concerned it would spook the dragonfly if I were to get “up in her grill.” So I waited until Mike had taken all of the photographs he wanted before approaching the dragonlfy for her “beauty shot.” As it turns out, the model was extraordinarily tolerant and didn’t fly away until sometime after Mike and I moved on to the next site.

21 MAY 2019 | PNC. William County, VA | Arrowhead Spiketail (female)

Notice the interrupted fern (Osmunda claytoniana) that appears in the background of every photo of the Arrowhead Spiketail.

Location, location, location.

Some species of odonates are habitat generalists, meaning they can be found almost anywhere there is water.

Habitat-specific odonates can be found only in specific habitats — for these species, finding them is all about location, location, location. Arrowhead Spiketail dragonflies are habitat-specialists.

Habitat: Small swift streams and soft-bottomed muddy seeps in forest, also streams reduced to series of small pools during drier weather. As in some other spiketails, skunk cabbage often present. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 7081-7082). Princeton University Press. Kindle Edition.

Skunk cabbage (Symplocarpus foetidus) and interrupted fern (Osmunda claytoniana) were observed growing in a seep located between a dirt trail and the small stream where the Arrowhead Spiketail was spotted — the perfect place for several species of habitat-specific odonates!

The last photo shows the clearing along a small forest stream where several species of dragonflies were spotted, including the Arrowhead Spiketail featured in this blog post. The stream is no more than a few feet wide and only a few inches deep in most places.

The small stream where several species of dragonflies were spotted.

The backstory

Telephoto lenses can cause a type of distortion called “foreshortening,” as seen in the preceding photo. Mike Powell and I were standing at the edge of the stream bank trying to decide whether we wanted to go down the short, steep slope to explore the clearing when we spotted a large UFO, that is, an “Unidentified Flying Odonate.” Mike and I took “record shots” of the dragonfly; looking at the LCD of our cameras, we identified the UFO as a Gray Petaltail dragonfly (Tachopteryx thoreyi).

Mike and I had seen a Gray Petaltail at another location (near the beginning of our photowalk), but we were unable to photograph it. So down the bank we went! As it turns out, there were at least two Grays in the meadow: a female; and a male. As Mike was photographing one of the Gray Petaltails he noticed another “large dragonfly.” As we slowly moved closer to the new unknown dragonfly, I quickly realized Mike had spotted an Arrowhead Clubtail. Great catch, Mike!

Please see Female Arrowhead Spiketail dragonfly for Mike’s take on our shared experience.

Uncommon

Arrowhead Spiketail is classified as an uncommon species of odonate. The following map shows all official records for Arrowhead Clubtail (C. obliqua) in the United States of America.

DSA Distribution Viewer | Arrowhead Spiketail

Source Credit: Abbott, J.C. 2006-2019. OdonataCentral: An online resource for the distribution and identification of Odonata. Available at http://www.odonatacentral.org. (Accessed: May 27, 2019).

Key: blue dots = Dot Map Project; green dots = Accepted records; yellow dots = Pending records.

Our spotting of Arrowhead Spiketail is a new DSA record for Prince William County, Virginia.

Adult flight period

According to records for the Commonwealth of Virginia maintained by Dr. Steve Roble, Staff Zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage, the adult flight period for C. obliqua is 11 May to 17 July. The species is classified as uncommon. Its habitat is “small streams.”

Bear in mind, Dr. Roble’s records are for the entire state, therefore the adult flight period for C. obliqua seems to be longer than it is in reality. The adult flight period for a single site is probably shorter — more likely around one month. For example, according to records for Northern Virginia maintained by Kevin Munroe, former manager of Huntley Meadows Park, the adult flight period for Arrowhead is 28 May to 27 June (peaks in June).

Copyright © 2019 Walter Sanford. All rights reserved.

 

Cordulegaster sp. larva (ventral view)

February 22, 2019

Bob Perkins collected and reared an odonate larva/nymph from the Family Cordulegastridae (Spiketails). The larva died before it metamorphosed into an adult.

This post features a focus-stacked composite image that shows a ventral view of the preserved larva; a composite image showing the dorsal view will be published in my next blog post.

Cordulegaster sp. larva (female) | ventral view

This individual is a female, as indicated by her rudimentary ovipositor that can be seen on the ventral side of the specimen along the boundary between abdominal segments eight and nine (S8-9). Do you see it?

Related Resources

Tech Tips

Nine (9) photos were used to create the focus stack. A single focus point was positioned over select anatomical features; photos were taken at each point of interest.

The following equipment was used to shoot all of the photographs for the focus-stacked composite image, shown above: Canon EOS 5D Mark II digital camera, in manual mode; Kenko 20mm macro automatic extension tubeCanon EF100mm f/2.8L Macro lens (set for manual focus); and Canon MT-26EX-RT Macro Twin Lite set for “Master” mode, and several external flashes set for “Slave” mode including Canon 580 EX- and Canon 580EX II Speedlites and a Godox TT685C Thinklite TTL Flash fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.

Auto power-off was disabled for the camera and all external flash units.

Adobe Photoshop CC 2017 was used to create the focus-stacked composite image, as well as spot-heal and sharpen the final output.

Copyright © 2019 Walter Sanford. All rights reserved.

Test shots: “Generic Gomphid”

February 11, 2019

A larva/nymph in the Family Gomphidae (Clubtails) was collected by Bob Perkins from the New River in southwestern Virginia. The larva died before it metamorphosed into an adult.

Test shots of this beautifully preserved specimen were taken using a small-ish aperture of f/11 for greater depth of field. The following photos are “one-offs,” that is, not composite images.

Dorsal

80mm (120mm, 35mm equivalent) | ISO 200 | f/11 | 1/180 s | 0 ev

Bob’s best guess of the identity of the specimen is Phanogompus sp. I see several similarities between this larva and a Phanogomphus lividus exuvia (Ashy Clubtail) in my collection, so Bob’s tentative identification might be correct. More later after the specimen is keyed out.

Ventral

80mm (120mm, 35mm equivalent) | ISO 200 | f/11 | 1/180 s | 0 ev

This individual might be female, as indicated by the rudimentary ovipositor that can be seen on the ventral side of the specimen along the boundary between abdominal segments eight and nine (S8-9).

Related Resources

Tech Tips

The following equipment (shown below) was used to shoot the preceding photos: Fujifilm X-T1 digital camera; Fujifilm MCEX-16 extension tube; Fujinon XF80mm macro lensGodox XProF TTL Wireless Flash Trigger for Fujifilm camerasGodox TT685F Thinklite TTL Flash for Fujifilm CamerasGodox TT685C Thinklite TTL Flash for Canon Cameras fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier; and a Canon 580EX II Speedlite mounted on a Godox X1R-C TTL Wireless Flash Trigger Receiver for Canon. A new Godox TT685O Thinklite TTL Flash for Olympus/Panasonic Cameras was added to an array of radio-controlled external flash units used to light the specimen. All flashes were set for Manual Mode at 1/128 power.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen the final output.

Gear used for studio macro photography.

By the way, in case you looked at the preceding photo and wondered “What’s up with the crazy crop?” I used Photoshop to conceal some of the clutter in my kitchen. I set up my macro photo rig in the kitchen because it’s the largest uncarpeted area in my tiny apartment. Padded carpet is a poor surface for macro photography — the field of view from a tripod-mounted camera-lens-flash trigger combo shifts noticeably (and unacceptably) as one moves around the rig.

Copyright © 2019 Walter Sanford. All rights reserved.

Test shots: Unknown odonate exuvia

December 12, 2018

An odonate exuvia from an unknown species of dragonfly (Anisoptera) was collected by a good friend during April 2018 in Vienna, Austria.

Based upon the crenulations along the margins of the labium, I think the specimen is a member of either the Family Corduliidae (Emeralds) or Family Libellulidae (Skimmers). I need to clean the anal pyramid for a clearer look at the terminal appendages in order to identify the family.

One-off

The first photo is a “one-off,” that is, not a composite image. The focus point is on the face mask/head; the rest of the subject is in soft focus.

Anisoptera (unknown species) | exuvia (face/head-dorsal)

Composite images

The next two “photos” are three-layer focus-stacked composite images: For each image, the focus point is on the face mask/head in the first photo; the thorax in the second photo; and the terminal appendages in the third photo. The entire body of the exuvia is acceptably in focus, including most of the legs.

The specimen has dorsal hooks on some abdominal segments (exact number unknown without closer examination), and lateral spines on abdominal segments eight and nine (S8-9).

Anisoptera (unknown species) | exuvia (dorsal)

I think this individual might be a female, as indicated by what appears to be a rudimentary ovipositor that is visible on the ventral side of abdominal segment nine (S9).

Anisoptera (unknown species) | exuvia (ventral)

Post Update

Sincere thanks to Benoit Guillon and Christophe Brochard, members of the “Dragonflies and Damselflies – Worldwide Odonata” Facebook group, for kindly identifying this specimen as an exuvia from a Downy Emerald dragonfly (Cordulia aenea). Downy Emerald is a member of the Family Corduliidae (Emeralds).

The following photo shows a plastic container of 20 Downy Emerald dragonfly (Cordulia aenea) exuviae, collected by a good friend during April 2018 in Vienna, Austria. Thanks to field marks shared by Benoit Guillon, I was able to quickly determine that all of the exuviae are the same species as the specimen featured in this blog post.

Related Resource: Cordulia aenea: exuviae (1/2), by Benoit Guillon.

Tech Tips

The following equipment was used to shoot all of the preceding photographs: Canon EOS 5D Mark II digital camera, in manual mode; Kenko 20mm macro automatic extension tubeCanon EF100mm f/2.8L Macro lens (set for manual focus); and Canon MT-26EX-RT Macro Twin Lite set for “Master” mode, and several external flashes set for “Slave” mode including Canon 580 EX- and Canon 580EX II Speedlites and a Godox TT685C Thinklite TTL Flash fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.

Adobe Photoshop CC 2017 was used to create the two focus-stacked composite images, as well as spot-heal and sharpen the final output.

Copyright © 2018 Walter Sanford. All rights reserved.

Test shots: Brachytron pratense exuvia (female)

December 10, 2018

As if it weren’t challenging enough to identify odonate exuviae from species native to the United States of America (where I live), I just started working with some specimens collected by a good friend during April 2018 in Vienna, Austria.

I decided to start with a specimen that I recognized immediately as a member of the Family Aeshnidae (Darners). Here’s the decision tree used to identify the family.

  • The specimen has a flat labium that doesn’t cover the face (not mask-like).
  • Antennae are thin and thread-like (not club-like, as in Gomphidae larvae/euviae).
  • Eyes are large relative to the size of the head.

One-off

The first photo is a “one-off,” that is, not a composite image. The focus point is on the face mask/head; the rest of the subject is in soft focus. I think this is a good way to draw the viewer’s eyes to a specific part of a photo, while adding a sense of depth.

Hairy Dragonfly (Brachytron pratense) | exuvia (face/head-dorsal)

Composite images

The next “photo” is a three-layer focus-stacked composite image: The focus point is on the face mask/head in the first photo; the thorax in the second photo; and the terminal appendages in the third photo. The entire body of the exuvia is acceptably in focus, including the legs.

Notice the unusual shape of the head. Head shape can be used to identify some species in Family Aeshnidae. Source Credit: Sue Gregoire, personal communication. Kestrel Haven Migration Observatory.

In fact, several members of the “Dragonflies and Damselflies – Worldwide Odonata” Facebook group were able to identify this specimen based upon the shape of its head and eyes. Sincere thanks to Tim Termaat, Hartwig Stobbe, and Rob Strik for kindly identifying this specimen as an exuvia from a Hairy Dragonfly (Brachytron pratense), also known as a Hairy Hawker.

Hairy Dragonfly (Brachytron pratense) | exuvia (dorsal-lateral)

The last “photo” is a four-layer focus-stacked composite image: The focus point is on the head in the first and second photos; the thorax in the third photo; and the terminal appendages in the fourth photo. The entire body of the exuvia is acceptably in focus, including the legs.

This individual is a female, as indicated by the rudimentary ovipositor that can be seen clearly on the ventral side of abdominal segment nine (S9).

Hairy Dragonfly (Brachytron pratense) | exuvia (ventral)

Related Resources

Tech Tips

The following equipment was used to shoot all of the preceding photographs: Canon EOS 5D Mark II digital camera, in manual mode; Kenko 20mm macro automatic extension tubeCanon EF100mm f/2.8L Macro lens (set for manual focus); and Canon MT-26EX-RT Macro Twin Lite set for “Master” mode, and several external flashes set for “Slave” mode including Canon 580 EX- and Canon 580EX II Speedlites and a Godox TT685C Thinklite TTL Flash fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.

Adobe Photoshop CC 2017 was used to create the two focus-stacked composite images, as well as spot-heal and sharpen the final output.

Copyright © 2018 Walter Sanford. All rights reserved.

Handsome Meadow Katydid (female)

September 28, 2018

20 SEP 2018 | HMP | Handsome Meadow Katydid (female)

The preceding photograph shows a female Handsome Meadow Katydid (Orchelimum pulchellum) perched on the boardwalk in the central wetland area at Huntley Meadows Park, Fairfax County, Virginia USA.

Blue eyes are a good field marker for identifying Handsome Meadow Katydids. Notice the long, curved, reddish, scimitar-shaped 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 [endophytic oviposition]. Source Credit: Matt Pelikan, BugGuide group on Facebook.

Copyright © 2018 Walter Sanford. All rights reserved.

Stream Bluet damselflies (mating pair, in tandem)

August 5, 2018

A mating pair of Stream Bluet damselflies (Enallagma exsulans) was spotted during a stream-walk along South Fork Quantico Creek in Prince William Forest Park (PWFP), Prince William County, Virginia USA. This pair is in tandem.

After copulation, Stream Bluet engages in a form of guarding behavior known as “contact guarding,” in which the male and female fly “in tandem” to egg-laying sites. Contact guarding is used by some species of odonates to prevent aggressive males from hijacking the female.

26 JUN 2018 | PWFP | Stream Bluet (mating pair, in tandem)

Female E. exsulans is polymorphic, including two morphs: green or blue thorax; abdomen similar to male for both morphs. The female shown in the preceding photo is a green morph.

Look closely at the posterior end of the female’s abdomen. All female damselflies (and some species of dragonflies) use an ovipositor to insert fertilized eggs into vegetation (endophytic oviposition). Notice the white spheroid at the tip of her ovipositor. That’s either a single egg or egg cluster/mass, probably the former.

Now look at the male. He appears to be “recharging” for mating again: Sperm is transferred from the genital opening under abdominal segment nine (S9) to the secondary genitalia located under abdominal segment two (S2). Remember all dragonflies and damselflies have a 10-segmented abdomen.

Editor’s Notes

Thanks to my good friend Mike Boatwright, administrator of the Virginia Odonata Facebook group, for verifying my tentative identification of the species of damselfly. Also thanks to Sue Gregoire, Kestrel Haven Migration Observatory, for sharing her expert opinion that my photo shows a single egg at the tip of the female’s ovipositor.

Copyright © 2018 Walter Sanford. All rights reserved.


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