This blog post features more photos of an exuvia from an unknown species of odonate that was collected by Joe Johnston on 07 August 2019 along Aquia Creek at Channel Marker No. 34, Stafford County, Virginia USA.
The specimen is probably from either Family Corduliidae (Emeralds) or Family Libellulidae (Skimmers).
07 AUG 2019 | Aquia Creek | dragonfly exuvia (dorsal view)
The rule of thumb for differentiating Corduliidae exuviae from Libellulidae is as follows: It’s probably Corduliidae if the cerci are at least half as long as the paraprocts; it’s probably Libellulidae if the cerci are less than half the length of the paraprocts.
07 AUG 2019 | Aquia Creek | dragonfly exuvia (ventral view)
I’m having a hard time seeing the cerci clearly. If I’m seeing what I think I’m seeing, then the cerci are at least half as long as the paraprocts and the exuvia is from Family Corduliidae (Emeralds).
In order to verify my tentative identification, I need to use a higher magnification macro lens (such as my Canon MP-E 65mm Macro lens) in order to shoot a close-up view of the anal pyramid/terminal appendages (see inset diagram, lower-left corner).
Related Resource: MYN – Dragonfly exuvia (unknown species)
Tech Tips
This specimen was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique. I used the new variation on my old MYN studio rig and I’m still satisfied with the results.
Copyright © 2020 Walter Sanford. All rights reserved.
Tags: Aquia Creek, BoG Photo Studio, exuvia, Family Corduliidae (Emeralds), Family Libellulidae (Skimmers), Meet Your Neighbours, Stafford County, studio photography, Virginia
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