Unicorn Clubtail dragonfly (male)

A Unicorn Clubtail dragonfly (Arigomphus villosipes) was photographed near the shoreline of a small pond at an undisclosed location in Fairfax County, Virginia USA.

This individual is a male, as indicated by his terminal appendages. 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”).

For those of you keeping score at home, notice male Unicorn terminal appendages have four points/prongs. Does that mean A. villosipes is an exception to the rule of three terminal appendages for male dragonflies? In a word, no.

05 JUN 2021 | Fairfax County, VA | Unicorn Clubtail (male)

The preceding photo shows a clear view of the male’s terminal appendages. Zoom-in on the full-size version of the photo and you should notice that the epiproct for Unicorn Clubtail is essentially a wide plate with two points/prongs.

Related Resource: Odonate Terminal Appendages – a permanent reference page in my blog featuring identification guides for most of the common species of odonates found in Virginia, and even some of the uncommon to rare species.

Copyright © 2021 Walter Sanford. All rights reserved.


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One Response to “Unicorn Clubtail dragonfly (male)”

  1. Wally Jones Says:

    Very nice description of appendages and I have bookmarked your link for future reference.

    Another splendid photograph.
    Another species not found around here.

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