Archive for August, 2022

What’s wrong with these pictures?

August 23, 2022

Remember “What’s wrong with this picture?” puzzles? For example, a kangaroo hidden in a tower of giraffes. That’s right, “tower” is the collective noun for a group of giraffes. So what’s wrong with the following pictures?

Nothing is “wrong” with the pictures, other than the fact that they are quick-and-dirty photos taken using my Apple iPad mini 6 camera and built-in flash. But there is something incongruous. Look closely and you should notice that a Canon lens is mounted on a Fujifilm camera body. How is that possible?

A closer view shows a Fringer EF-FX Pro II lens mount adapter located between the Canon lens and Fujifilm camera body. Net result: The Canon lens works with my Fufifilm camera just like Fujifilm/Fujinon lenses.

During limited testing, the lens worked perfectly with the camera. I plan to post some test shots in an upcoming blog post.

The Backstory

The Canon EF 100mm macro lens is one of my favorite lenses — it takes tack-sharp photos that look great! I don’t use the lens as often as I should because my Canon EOS 5D Mark II DSLR isn’t as feature-rich as relatively newer digital cameras such as my Fujifilm X-T3.

I’ve been thinking about upgrading my 5D Mark II to one of the two new Canon APS-C sensor camera models, but for now I decided to save money and buy the Fringer adapter instead. So far so good!

Related Resources

Copyright © 2022 Walter Sanford. All rights reserved.

Pantala versus Tramea exuviae/larvae

August 12, 2022

Sometime during the late 1950s or early 1960s, my father bought a new car. That was a big deal in our family. My family was poor, although I didn’t realize it when I was a young boy. We couldn’t afford a new car very often. I don’t remember many details about the car other than it was a sky blue Plymouth with tail fins. Big tail fins! My best guess is the car was a four-door Plymouth Fury, sold from 1957 – 1960.

Some odonate exuviae/larvae remind me of the tail fins on my father’s Plymouth automobile. Go figure. Anyway, pattern recognition can be used to make it a little easier to identify exuviae. For example, when I see an exuvia with long “tail fins,” my first thought is it’s probably from one of two genera, possibly three: genus Pantala; genus Tramea; or maybe genus Celithemis.

Dichotomous keys

The following couplet from Identification Keys to Northeastern Anisoptera Larvae, compiled by Ken Soltesz, can be used to differentiate exuvia from Genus Pantala and Genus Tramea.

p. 37, Key to the Genera of the Family Libellulidae
12a – Superior abdominal appendage (epiproct) as long as, or longer than inferiors [paraprocts]. Pantala
12b – Superior abdominal appendage (epiproct) shorter than inferiors [paraprocts]. Tramea

Soltesz, p. 39.

Soltesz, p. 40.

Soltesz, p. 41.

Genus Pantala (Rainpool Gliders)

The genus Pantala includes two (2) species in North America: Spot-winged Glider (Pantala hymenaea); and Wandering Glider (Pantala flavescens).

Spot-winged Glider and Wandering Glider larvae/exuviae look similar. The lateral spines on abdominal segment nine (S9) are noticeably shorter for P. hymenaea (shown left) than P. flavescens (shown right) — a key field mark that can be used to differentiate the two species.

Genus Tramea (Saddlebags)

The genus Tramea includes seven (7) species in North America. Two of those species are found commonly in the Commonwealth of Virginia: Black Saddlebags (Tramea lacerata); and Carolina Saddlebags (Tramea carolina).

Carolina Saddlebags

A Carolina Saddlebags dragonfly (Tramea carolina) larva was collected by Andy Davidson near Richmond, Virginia USA, and reared to maturity. Andy saved the exuvia after emergence.

A vertical white line marks the mid-dorsal length of abdominal segment nine (S9), as shown in the following annotated image; the vertical black line labeled “mid-dorsal length” is the same length as the white line. Notice the lateral spines of abdominal segment nine (S9) are much longer than its mid-dorsal length.

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

One of the keys to identifying skimmer dragonflies to the species level is to carefully examine the anal pyramid (S10), including the cerci (sing. cercus), epiproct, and paraprocts. Notice the epiproct is shorter than the paraprocts.

There is a lot of “seaweed” (aquatic vegetation) clinging to the exuvia, especially noticeable at the posterior end. Some collectors like to clean their specimens; I prefer to photograph them “as is.”

Black Saddlebags

Athough adult Black Saddlebags dragonflies (Tramea lacerata) are relatively common in Virginia, the author has never seen an exuvia from this species.

Genus Celithemis (Pennants)

The genus Celithemis includes eight (8) species in North America. The author has a specimen from only one of these species in his collection.

Calico Pennant dragonfly (Celithemis elisa) evuvia was collected by Sue and John Gregoire at Kestrel Haven Migration Observatory. For more than a decade, Sue and John have closely monitored the annual emergence of a large population of C. elisa at their farm pond.

Notice the long lateral spines that look similar to larvae/exuviae in genus Pantala and genus Tramea.

Related Resources

Identification Keys to Northeastern Anisoptera Larvae, compiled by Ken Soltesz.

  • p. 36 = Key to the Genera of Family Libellulidae
  • p. 37 = Pantala, Tramea
  • p. 39 = Key to the species of genus Pantala: hymenaea; flavescens
  • p. 41 = Key to the species of genus Tramea: carolina; lacerta

A Checklist of North American Odonata – Including English Name, Etymology, Type Locality, and Distribution, by Dennis R. Paulson and Sidney W. Dunkle.

Copyright © 2022 Walter Sanford. All rights reserved.


August 2, 2022

In Japanese, the word “kaizen” literally means improvement.

The Japanese word kaizen means ‘change for better,’ with the inherent meaning of either ‘continuous’ or ‘philosophy’ in Japanese dictionaries and in everyday use. The word refers to any improvement, one-time or continuous, large or small, in the same sense as the English word improvement. Source Credit: Kaizen, Wikipedia.

I wonder whether regular readers of my blog have noticed that many posts are updated and/or improved after they are posted. And so it is with the Identification Guide for Family Macromiidae (Cruisers) in Virginia that was published recently.

We corrected a typo (changed “boarder” to “border”) that spell-check missed, added a pointer to a range map for the two subspecies of Swift River Cruiser (see Related Resources), and updated the interactive version of the PDF (already published).

Finally we created a new, non-interactive version of the PDF. The following screenshot shows what the new document looks like.

(See the complete, non-interactive PDF version of the ID guide.)

Related Resources

Copyright © 2022 Walter Sanford. All rights reserved.

%d bloggers like this: