Common Sanddragon dragonflies (mating pairs)

I spotted two mating pairs of Common Sanddragon dragonflies (Progomphus obscurus) during a photowalk at Huntley Meadows Park on 20 June 2014; both pairs are shown in the “mating wheel.”

Pairs copulate for up to 15 minutes on ground or in shrubs near water. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 4856-4857). Princeton University Press. Kindle Edition.

Both pairs began mating on the banks of the stream and moved to vegetation near the water a few minutes later.

Photo 1. Mating pair one.

Photo 2. Mating pair one, a few minutes later.

Common Sanddragons are a species of dragonfly formerly unknown to occur at Huntley Meadows before their discovery by Mike Powell on 17 June 2014. It’s good to know there’s a reproducing population of sanddragons at the park, as evidenced by the photos in this gallery.

Photo 3. Mating pair two.

Photo 4. Mating pair two, a few minutes later.

It’s fairly simple and straightforward to identify the male- and female members of a mating pair of dragonflies. All dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back: male dragonfly secondary genitalia, called hamules, are located in segments two and three (2 and 3); female genitalia in segment eight (8). Dragonflies form the mating wheel in order for their genitalia to connect during copulation.

All 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”). In every photo, shown above, the male dragonfly is the one using his claspers to hold the female by her head.

It is more challenging to identify single male and female dragonflies, especially when their appearance is similar. Ed Lam, author and illustrator of Damselflies of the Northeast, created the following composite image that shows how to differentiate male and female Common Sanddragons. Notice the difference in the shape of male and female hind wings: male hind wings are “indented” near the body; female hind wings are rounded. This easy-to-recognize field marker is shown most clearly in the full-size version of Photo 3, shown above.

Copyright © 2014 Walter Sanford. All rights reserved.

Tags: adult female, adult male, cerci, claspers, Clubtail Family, Common Sanddragon dragonfly, epiproct, hamules, Huntley Meadows Park, in wheel, mating pair, Progomphus obscurus, terminal appendages, wildlife photography