A Dragonhunter dragonfly (Hagenius brevistylus) exuvia was collected along the Little Patuxent River by Richard Orr, renowned expert on odonates of the mid-Atlantic region of the United States, during an Audubon Naturalist Society adult class and field trip to the Patuxent Research Refuge on 15 June 2014.
Dragonhunter [nymphs] crawl out of the river and often cling on wet wood or roots/vegetation. I have seen them on mud but they seem to like vegetation or wood to cling to during emergence. I took a photo…of a cast skin at the same area [where this specimen was collected]. Source Credit: Personal communication from Richard Orr.
The decision tree used to identify the exuvia as a member of the Gomphidae Family (Clubtails) is fairly simple and straightforward.
- The specimen has a flat labium (not mask-like).
- Antennae are either club-shaped or paddle-like (not thin and threadlike as in Aeshnidae).
Dragonhunter is the largest of North American clubtails; accordingly the large size and shape of a Dragonhunter exuvia is so distinctive that it is relatively easy to identify to the species level.
Lateral view showing left side, facing forward (annotated).
(See a full-size version of the original photo, without annotation.)
Notice the large, paddle-like antennae. They remind me of ping pong paddles.
Head-on view (annotated).
(See a full-size version of the original photo, without annotation.)
The large size and shape of Dragonhunter exuviae are key field markers.
Dorsal view.
All clubtail nymphs/evuviae have a flat labium that doesn’t cover the face.
Ventral view (annotated).
(See a full-size version of the original photo, without annotation.)
Tech Tips:
The following equipment was used to shoot the preceding photographs: Fujifilm X-T1 digital camera; Fujinon XF18-55mm (27mm-82.5mm, 35mm equivalent) zoom lens plus “Fotasy” brand 10mm extension tube; Fujifilm Shoe Mount Flash EF-42 (on-camera, in TTL mode); Nissin i40 external flash unit (off-camera, in SD mode). A snap-on plastic diffuser was used for each external flash.
Adobe Photoshop CC 2015 was used to annotate selected images.
Related Resources:
- Photo showing dorsal view of a Dragonhunter exuvia (in situ), taken by Richard Orr on 01 June 2016 along the Little Patuxent River, Patuxent Research Refuge.
- Photo showing dorsal view of a Dragonhunter nymph [ruler shown for scale], embedded on the following Web page: “Dragons and Damsels”: Odonata, Pt. I.
- Photo of a Dragonhunter naiad [nymph] (Hagenius brevistylus), showing a good head-on view of the paddle-like antennae.
- Odonate Exuviae, by Walter Sanford
Copyright © 2016 Walter Sanford. All rights reserved.
Tags: Clubtail Family, Dragonhunter dragonfly, exuvia, gear talk, Gomphidae, Hagenius brevistylus, Patuxent Research Refuge, wildlife photography
June 24, 2016 at 4:06 am |
[…] Resource: Dragonhunter dragonfly exuvia, a blog post by Walter […]