Archive for December, 2022

How to watch ‘A Charlie Brown Christmas’ for free on Apple TV+

December 20, 2022

“A Charlie Brown Christmas” is my favorite Christmas special, by far. It’s a masterpiece, in my opinion.

The title of the following article from Macworld is somewhat misleading — you don’t need a subscription to Apple TV+ in order to watch the program.

From December 22 to 25, anyone with an Apple ID can watch “A Charlie Brown Christmas.” Anyone who owns an Apple device has an Apple ID, but if you don’t, Apple IDs are free and you don’t need a credit card to sign up. Once you have signed up, you can watch in a number of ways: … Source Credit: How to watch ‘A Charlie Brown Christmas’ for free on Apple TV+

The “True Meaning” of Christmas is my favorite scene in the program.

Copyright © 2022 Walter Sanford. All rights reserved.

Dragonfly Curriculum Guide Supplemental Videos

December 16, 2022

One of my photos is featured in a new video entitled Determining Dragonfly Sex: Dragonfly video 15, by Dr. Ami Thompson. See the inset photo in the following video screen capture.

The video is one of 15 Dragonfly Curriculum Guide Supplemental Videos coproduced by Ami Thompson and Peter Xyooj. The Dragonfly Curriculum Guide (PDF) is available for free.

Notice my last name is misspelled in the credits at the end of the video: Stanford is an institution; I should be institutionalized. <Rim shot!> Oh well, at least my name is spelled correctly in the video screen capture shown above.

The inset photo is from “Mocha Emerald dragonfly claspers,” a blog post that I published on 13 July 2017.

09 JUL 2017 | Huntley Meadows Park | Mocha Emerald (male)

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Copyright © 2022 Walter Sanford. All rights reserved.

Common Green Darner exuviae (male vestigial genitalia)

December 6, 2022

Male odonates in Suborder Anisoptera (Dragonflies) have two sets of sex organs: primary genitalia located on abdominal segment nine (S9); and secondary genitalia located on abdominal segments two-to-three (S2-3).

For some (but not all) species of odonate larvae/exuviae, sex is indicated by either a rudimentary ovipositor (female) or vestigial genitalia (male). These sex organs don’t look exactly the same for all species of dragonflies, but their function is identical.

The following annotated images show the male vestigial genitalia for two Common Green Darner (Anax junius) exuviae collected by Jason Avery during Summer 2022 in Calvert County, Maryland USA. All of the images show the ventral side of the exuviae.

Male No. 1

Summer 2022 | Common Green Darner (Anax junius) | exuvia (male)

Summer 2022 | Common Green Darner (Anax junius) | exuvia (male)

Male No. 2

Summer 2022 | Common Green Darner (Anax junius) | exuvia (male)

Look closely at the following image and you should notice the secondary genitalia appear to extend from S2 to S3. In this case, only the more prominent parts on S3 are labeled.

Summer 2022 | Common Green Darner (Anax junius) | exuvia (male)

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All of the preceding images were photographed by Jason Avery and annotated by Walter Sanford. Thanks to Jason for kindly sharing his photos!

Copyright © 2022 Walter Sanford. All rights reserved.

Post update: Which family is it?

December 2, 2022

The following odonate exuvia is from a damselfly in Suborder Zygoptera.

The overall shape of the prementum (highlighted by a red rectangle) indicates this specimen is from Family Calopterygidae (Broad-winged Damselflies). Notice the embedded raindrop shape (highlighted by a purple rectangle), located toward the upper-center of the prementum — a key field mark for this family.

03 SEP 2022 | Powhatan County, VA USA | (exuviaventral side)

Two genera from Family Calopterygidae are common in the Commonwealth of Virginia: Hetaerina; and Calopteryx. For species in Genus Calopteryx the raindrop shape (Fig. 19) looks more like a diamond shape (Fig. 18), so it’s probably safe to infer this specimen is a species in Genus Hetaerina.

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Post Update: Congratulations to Doug Mills, Wally Jones, and Bob Perkins for correctly identifying the family of this exuvia.

Doug and Wally looked at the shape of the prementum. Bob looked at the antennae.

The long middle segment on the antennae is the key, found only on Calopterygidae nymphs. Nymphs of the other families have antenna segments that are progressively shorter from base to tip. Source Credit: Bob Perkins.

Looking at the prementum should enable you to identify all three families; looking at antennae works for only one family.

Copyright © 2022 Walter Sanford. All rights reserved.

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