This week, we have the species Gomphus exilis Selys 1854 (Odonata: Gomphidae). Gomphidae are commonly referred to as clubtails due to the posterior most abdominal segments being expanded to form a “club”. Gomphus exilis is called the lancet clubtail because of the lancet shaped claspers at the posterior end of the abdomen that are used to clasp the female just behind the head during mating.
Gomphidae is a diverse family with 46 species found in North Carolina. Unfortunately we don’t have many specimens of this family in our research or teaching collections.

This species was described in 1854 by Michel-Edmond de Sélys-Longchamps, a Belgian politician and biologist.

The original description by Selys is in French, however the description given by Needham, Westfall and May (2000) defines the same characters used by Selys. Here is their description:

A small greenish yellow species, diffusely striped with pale brown. Vertex brown, paler on rearward slope of postocellar ridge, Middorsal thoracic stripe widens downward into a broad triangle. Antehumeral brown stripe free at upper end and well separated from humeral by a more or less complete line of greenish yellow. Sides of thorax yellowish with complete brownish interpleural and metapleural stripes. Area between these stripes more or less brownish. Femora brownish, paler beneath; wide stripes of yellow on outer side of tibia run down on top of tarsal segments.

Abdomen predominantly brownish. Its middorsal pale line nearly continuous, narrowed on middle segments, narrowed most on 8, broadened and diffused on 9 and 10. Slightly dilated lateral margins of 7-9 dull yellow; caudal appendages brown. Posterior hamule of male yellow.

Needham et al. 2000 also provides keys to identify dragonflies of found in North America to species.

All dragonflies are areal predators as adults and predators of aquatic invertebrates as nymphs. This is the time of year that adults of this and many other species can be seen hunting near water features such as Lake Johnson, where some of our museum specimens have been caught.

Gomphus exilis has an extremely broad distribution. In Canada, its range extends from Manitoba to Nova Scotia. In the US, its range covers almost half of the country extending from Maine to Florida in the east, and Minnesota to Louisiana in the west.

• Sélys-Longchamps, Michel-Edmond. 1854. Synopsis des Gomphines. Bulletin de l’Académie royale des Sciences de Belgique 21:23-114.
• Gomphus exilis page at GBIF (158 records as of 9 June 2011)
• Needham, James G., Westfall, Minter J. Jr, May, Micheal L. 2000. Dragonflies of North America, Revised Edition. Scientific Publishers. Gainesville, Florida. p207-454.