Jumping spider

The following photo shows a tiny spider carcass (~3/16″ long) that was inside an exuvia (~1 3/4” long) from a Common Green Darner dragonfly (Anax junius). The exuvia was collected on 17 June 2021 from a small pond in Prince William County, Virginia USA. I discovered the spider long afterward — too late to save its life.

17 JUN 2021 | PNC. Wm. County, VA | Jumping spider

Thanks to Eva Weiderman and Joseph Girgente — members of the “Odonate Larvae and Exuviae” Facebook group — for their help in identifying the specimen as a jumping spider, Family Saticidae.

Salticidae is one of several families of spiders with eight (8) eyes. My take-away from reading the reference on BugGuide entitled “Spider Eye Arrangements” is identification of this specimen to the genus and species level is challenging at best and impossible at worst.

In contrast, it’s well known that spiders use odonate exuviae for shelter. I wish the jumping spider had come out of its most excellent hidey-hole sooner!

17 JUN 2021 | PNC. Wm. County, VA | Anax junius exuvia

Related Resources

• Spider Eye Arrangements, by BugGuide. See Family Salticidae.
• Nature Abhors a Vacuum, by Douglas Mills.
• Post update: What is it? [Anax junius exuvia, shown above.]

Tech Tips

The tiny jumping spider was photographed using a Panasonic Lumix FZ-300, Raynox DCR-250 close-up filter, Godox X2To/p flash trigger, and Godox TT685F plus Altura flash modifier. Camera settings: ISO 100 | f/7.1 | 1/60 s | 56.9mm (316mm, 35mm equivalent).

“Raynox DCR-250 close-up filter” is a blog post in which I provide more information about how I use the Raynox with my Panasonic Lumix superzoom bridge cameras.

Copyright © 2022 Walter Sanford. All rights reserved.

Post update: What is it?

The mystery item featured in my last blog post is a Christmas tree ornament hanging above a battery-powered flashlight with a low-power incandescent bulb.

Perhaps the bigger mystery is what makes the gold propeller inside the ornament spin around when the flashlight is powered-on.

Christmas tree ornament hanging above a flashlight.

Energy Transformations

When I taught 8th grade Physical Science classes, “energy transformations” was an overarching theme in one of the lab manuals for the course.

The Rayovac No. H22 Industrial Flashlight (shown above) uses two 1.5 V D-cell batteries to power a 2.4 V incandescent bulb. When the flashlight was powered-on and placed below the Christmas tree ornament, the following energy transformations occured.

potential energy → chemical energy → electrical energy →
radiant energy → thermal energy → kinetic energy

Knowing that kinetic energy can be thought of as energy of motion, the question remains: What gives the spinning propeller its kinetic energy?

Heat Rises

How many times have you heard this common misconception? “Heat,” more correctly referred to as “thermal energy,” flows from higher to lower concentration of thermal energy, regardless of directions such as up or down. So what causes the propeller to spin?

Thermal energy from the incandescent flashlight bulb causes the temperature of the air around the flashlight bulb to increase. The warm air around the bulb is less dense than the surrounding air so it rises; the rising air current causes the gold propeller inside the Christmas tree ornament to spin. It’s worth noting I removed the plastic “lens” from the face of the flashlight head so it wouldn’t block airflow from the light bulb to Christmas tree ornament.

The Backstory

The Christmas tree ornament shown above is a treasured memento from my early childhood. My parents bought two similar ornaments: one is blue with a gold propeller; the other is green with a red propeller (not shown).

One of the ornaments was a gift for my sister; the other was for me. I can’t remember which one was given to me. In my defense, that was a long time ago — I might have been as young as three or four years old when we got the ornaments. That said, I remember clearly how fascinated I was with the spinning propeller inside the ornament!

At that time, Christmas tree lights were relatively large colored incandescent bulbs that got uncomfortably warm-to-hot when powered-on. When my Christmas tree ornament was hung above one of those lights, the propeller spun much faster than it did when hanging above the smaller flashlight bulb used for my demonstration.

Related Resource: Candle Powered Carousel (1:01). My family had one of these too.

Copyright © 2022 Walter Sanford. All rights reserved.

Comet Darner exuvia: photo sketch pad

Sometimes I shoot test shots of an odonate exuvia that are used to plan the final shots I have in mind for an identification guide featuring annotated photos.

All of the shots in this post are unedited JPGs straight from my camera, with the exception of the first ventral view (cropped to remove a distracting element from the composition).

Lateral view

I started with a lateral view of an exuvia from a Comet Darner dragonfly (Anax longipes) exuvia collected by Stanley Caveney on 19 July 2021 from a pond at MeadowWoods in West Elgin, Ontario, Canada.

Comet Darner (Anax longipes) | exuvia (lateral)

Ventral view

The next two photos show my frustratingly poor attempts to pose the specimen for shots of the ventral side of the exuvia. Every time I positioned the subject the way I wanted, it rolled over before I could take a shot!

Comet Darner (Anax longipes) | exuvia (ventral)

The two shots combined show the vestigial primary- and secondary genitalia that indicate this specimen is from a male Comet Darner. Yeah, I know it would help to annotate those parts of its anatomy, but that’s the next step. In the meantime, please follow the embedded hyperlink shown above and you might be able to figure out what I’m saying.

Comet Darner (Anax longipes) | exuvia (ventral)

Prementum

The last photo shows a closer view of the prementum. My goal was to get a better look at the labial palps. Again, annotations would help, but if you know what I’m talking about then you can see the palpal lobes are squared off.

Comet Darner (Anax longipes) | exuvia (prementum)

Copyright © 2021 Walter Sanford. All rights reserved.

Post update: What is it?

Since I started exploring ways to provide continuous power for my digital cameras, I have been guided by two questions. 1. Will it work? 2. Is it safe? I watched a YouTube video recently that reminded me of the latter question.

External Power for Cameras, the Safest Options by Graham Houghton (14:53) inspired me to search online for an inline voltage meter with USB connectors.

Drok USB Tester

After watching several more YouTube videos, I decided to buy a Digital Meter USB Tester Multifunction Digital Voltmeter/Ammeter/Power Meter/Capacity Tester/Charger 5in1 USB Panel Meter, available from a company in the United States called “Drok.” The MSRP for the Drok USB Tester is $15.99. The one I ordered from the Drok Store on Amazon cost $9.99.

Product image courtesy Droking.com.

The device features one male USB connector for input, and two female USB connectors for output.

Product image courtesy Droking.com.

GyroVu continuous power adapter

The next photo shows a GyroVu USB TO PANASONIC DMC-GH2 (DMW-BLC12) BATTERY 40″ CABLE w/ 3.1A USB POWER SUPPLY. The device can be used to provide continuous power for my Panasonic Lumix DMC-FZ300 superzoom bridge camera.

Product image courtesy GyroVu.com.

The “USB Charger” — a small white power brick — was plugged into a 120V AC electrical outlet. Look closely at the full-size version of the following image. Notice the USB Charger output is 5V=3.1A. (3.1A = 3100mA.)

Product image courtesy GyroVu.com.

Testing the GyroVu continuous power adapter

The Drok USB Tester was connected to the 3100mA USB connector on the GyroVu USB Charger, shown above.

The USB cable for the GyroVu dummy battery was connected to “Output 1” of the Drok USB Tester; the dummy battery was inserted into the battery compartment of my Panasonic Lumix DMC-FZ300.

The last photo — the same one featured in my last blog post — shows the LED display on the front of the Drok USB Tester after my camera was powered on, indicating the output voltage of the USB Charger was 5V and the camera was drawing a current of 0.45A.

Panasonic Lumix DMC-FZ300 (121mm) plus Raynox DCR-250.

The output voltage of the GyroVu dummy battery is 8.0V so the “dummy” battery must contain a DC-to-DC step-up converter.

I plan to use a multimeter to test the actual voltage output of the GyroVu dummy battery, that is, as soon as I can find my RadioShack mulitimeter. (Someday I’ll get organized so I know where everything is!)

Sidebar: Deep Dive into Tech Specs

The Web page for the GyroVu continuous power adapter shown above says the product is for the Panasonic DMC-GH2 camera. How could I be sure the device would work with my Panasonic Lumix DMC-FZ300 digital camera?

The Panasonic Lumix DMC-FZ300 uses a Panasonic DMW-BLC12 Rechargeable Lithium-Ion Battery (7.2V, 1200mAh). Turns out that’s the same battery used by the Panasonic DMC-GH2. I know this thanks to Wasabi Power for providing a list of Panasonic cameras that use the DMW-BLC12 battery. (See the Web page for the PANASONIC DMW-BLC12 AC POWER ADAPTER KIT WITH DC COUPLER FOR PANASONIC DMW-DCC8, DMW-AC8 BY WASABI POWER, a product similar to the GyroVu continuous power adapter.)

Editor’s Note: The MSRP for the Wasabi Power continuous power adapter is $23.99 — nearly $10 less than the MSRP of $33.95 for the GyroVu USB Power Supply. You might be wondering why I didn’t buy the Wasabi Power device.

Notice the Wasabi Power device uses round connectors rather than USB connectors. I prefer the GyroVu devices because the USB connectors on their dummy batteries give me the flexibility to use them with my Anker PowerCore+ 26800 PD 45W battery as a power source for select Canon, Fujifilm, and Panasonic digital cameras that I own.

Related Resources

This blog post is one in a series of posts related to continuous AC power and long-lasting battery power for select Canon, Fujifilm, and Panasonic digital cameras.

• Anker PowerCore+ 26800 PD 45W
• Will it work? Is it safe?
• Continuous power: Canon EOS 5D Mark II
• Continuous power: Fujifilm X-T3
• Continuous power: Panasonic Lumix DMC-FZ300
• The best of both worlds at bargain prices

Copyright © 2021 Walter Sanford. All rights reserved.

What is it?

Ladies and gentlemen, children of all ages. It’s time for another exciting episode of “What is it?”

If you think you know what is shown in the preceding photo, then please leave a comment. The answer will be revealed in a post update.

Editor’s Note: OK, OK — I realize this one is beyond challenging and might turn out to be impossible to identify correctly. But hey, take a guess anyway — you might be right!

Copyright © 2021 Walter Sanford. All rights reserved.

Yellow-sided Skimmer (terminal appendages)

Female and male Yellow-sided Skimmer dragonflies (Libellula flavida) were spotted at a small pond at an undisclosed location in Prince William County, Virginia USA.

Female

The first individual is a female, as indicated by her mostly yellow coloration and terminal appendages.

17 JUN 2021 | PNC. Wm. County | Yellow-sided Skimmer (female)

Female dragonflies have a pair of cerci (superior appendages) that have little or no function.

Mature male

The last individual is a mature male, as indicated by his light-blue pruinescence and terminal appendages.

17 JUN 2021 | PNC. Wm. County | Yellow-sided Skimmer (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”).

Immature male Yellow-sided Skimmers look similar to females of the same species. Terminal appendages can be used to differentiate the sex of immature males and mature females.

Related Resource: Yellow-sided Skimmer (male and female) – a blog post by Walter Sanford.

Copyright © 2021 Walter Sanford. All rights reserved.

Black-shouldered Spinyleg (female)

A Black-shouldered Spinyleg dragonfly (Dromogomphus spinosus) was spotted by Michael Powell during a photowalk with me along a mid-size stream at an undisclosed location in Prince William County, Virginia USA.

This individual is a female, as indicated by her rounded hind wings and terminal appendages.

05 AUG 2021 | PNC. Wm. County | Black-shouldered Spinyleg (female)

We followed the female from one location…

05 AUG 2021 | PNC. Wm. County | Black-shouldered Spinyleg (female)

to another.

05 AUG 2021 | PNC. Wm. County | Black-shouldered Spinyleg (female)

I was able to take no more than three shots at each perch before she moved on to the next stop.

05 AUG 2021 | PNC. Wm. County | Black-shouldered Spinyleg (female)

Habitat

I’m not sure I’d call Black-shouldered Spinyleg a habitat specialist. I’ve seen and photographed D. spinosus along small streams in the forest, mid-size streams (like the one in this post), and large rivers.

Habitat: Rocky and muddy streams and rivers from small to large, more often in woodland. Also in rocky lakes in northern part of range. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 6416-6417). Princeton University Press. Kindle Edition.

Range map

The following map shows all official records for Dromogomphus spinosus in the United States of America. Given the wide range of lotic habitats where Black-shouldered Spinyleg is found, I’m puzzled by the fact that the species isn’t more widespread than it appears to be.

Related Resource: All posts in my blog tagged with the words “Black-shouldered Spinyleg dragonfly.”

Copyright © 2021 Walter Sanford. All rights reserved.

Tiger Spiketail dragonfly (male)

A Tiger Spiketail dragonfly (Cordulegaster erronea) was captured along a small stream at an undisclosed location in Prince William County, Virginia USA. The specimen was photographed and released unharmed.

The first few images show Michael Powell, my former friend and photowalking buddy, holding the dragonfly while I shot some photographs.

05 AUG 2021 | Prince William County, VA | Tiger Spiketail (male)

This individual is a male, as indicated by his hamules, “indented” hind wings, and terminal appendages.

05 AUG 2021 | Prince William County, VA | Tiger Spiketail (male)

What a handsome face! Cue “Eye Of The Tiger” by Survivor.

05 AUG 2021 | Prince William County, VA | Tiger Spiketail (male)

The next image shows me holding the dragonfly so that Mike could take some photographs. Hold That Tiger. (Strike up the band!)

Photo used with written permission from Michael Powell.

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

Up, up, and away!

The last photograph shows the Tiger Spiketail “posed” au naturel on the trunk of a fallen tree. Mike and I chose that spot because it was one of only a few sunny places along the small forest stream. The Tiger flew away almost immediately after I released him, headed toward the tree canopy. Mike had time for one clear shot. Good thing, ‘cuz I had no opportunity to get a shot.

Photo used with written permission from Michael Powell.

The backstory

I went on my first Tiger safari during July 2018 when I visited a location in Fairfax County, Virginia that a friend shared with me in strictest confidence. Although I saw several Tiger Spiketail dragonflies, every individual was in flight and I was unable to shoot still photos and/or video — they were gone by the time I reached for my camera!

Every year for the next few years, the story was similar — I saw Tigers but had no photos/videos to verify my sightings. Eventually I came to the conclusion that I would need to capture a specimen with an insect net in order to take photographs.

Let me be perfectly clear — all things being equal I would prefer to photograph dragonflies perching naturally rather than netting them. Sometimes, as in this case, netting is the better way to go.

Rest assured I have great respect for the rare- to uncommon species of odonates. The Tiger Spiketail featured in this post was held in captivity no longer than absolutely necessary, and was handled gently at all times.

Our strategy

Mike and I arrived at the stream site sometime after 10 a.m. While I setup my 18” diameter collapsible insect net, Mike took the point a little farther downstream to look for a Tiger approaching our location. No more than 10 minutes after I was in position alongside the stream, Mike spotted a Tiger flying upstream in our direction.

I waited until the Tiger had almost reached the place where I was standing before I swung my net forward smoothly and was psyched to see the dragonfly go all the way into the net. I said to Mike, “I got it!”

From that point, I worked quickly to gently remove the dragonfly from the net so that Mike and I could take some photographs of this rare species.

Range map

The following map shows all official records for Cordulegaster erronea in the United States of America. Tiger Spiketail is a habitat specialist that is challenging to find.

Related Resources

• Anatomy of a male Tiger Spiketail – a photo-illustrated identification guide by Walter Sanford.
• Habitat for Tiger Spiketail dragonfly – a blog post by Walter Sanford, published on 09 August 2018.
• Habitat for Tiger Spiketail dragonfly – a follow-up blog post by Walter Sanford, published on 09 August 2019. The location shown in the 2019 post is the same one where we photographed the C. erronea shown above.
• Tiger Spiketail Dragonfly at White Clay Creek State Park, by Delaware State Parks (10:56). Featuring former University of Delaware Professor Hal White.
• BioQuip Collapsible Insect Nets
• How To Unfold and Fold A Collapsible Insect Net, by BioQuip (1:23)
• Cordulegaster erronea Tiger Spiketail on NatureServe Explorer. The conservation status for C. erronea in Virginia is “Vulnerable (S3).”

Copyright © 2021 Walter Sanford. All rights reserved.

Bridge across Quantico Creek

The following photos show a small wooden bridge across Quantico Creek, near Burma Road in Prince William Forest Park, Prince William County, Virginia USA.

13 MAY 2021 | PNC. Wm. Forest Park | bridge across Quantico Creek

If you like bridges that bounce when you walk across them, then this is the bridge for you! I prefer bridges that are rock-solid.

13 MAY 2021 | PNC. Wm. Forest Park | bridge across Quantico Creek

Related Resource: All posts in my blog tagged with the word “bridge.”

Copyright © 2021 Walter Sanford. All rights reserved.

Ebony Jewelwing damselfly (male)

An Ebony Jewelwing damselfly (Calopteryx maculata) was spotted along a small stream located in Occoquan Regional Park, Fairfax County, Virginia USA.

05 JUN 2021 | Fairfax County, VA | Ebony Jewelwing (male)

This individual is a male, as indicated by his all black wings and terminal appendages.

05 JUN 2021 | Fairfax County, VA | Ebony Jewelwing (male)

Habitat

It’s easy to find Ebony Jewelwing. Look for a small stream in the forest.

Slow-flowing woodland streams, usually associated with herbaceous vegetation. Tend to be more at rapids when that habitat is present. Occur on open banks when trees nearby (trees essential for roosting at night). May be abundant at small streams in woods where very few other species are present. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 1249-1251). Princeton University Press. Kindle Edition.

Copyright © 2021 Walter Sanford. All rights reserved.