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Coleoptera of Great Smoky Mountains National Park Species Pages

Family Carabidae

            Tribe Platynini

 Agonum  (Stictanchus) extensicolle  (Say)

Description and Taxonomy

Length 7-10mm. This metallic Agonum species is distinctive due to the bright green or bluish iridescence on the dorsal surfaces. The elongate habitus with slender appendages, distinctive color, and the presence of 5-6 dorsal punctures with setae on each elytron make this species unmistakably different from other Appalachian species of the genus (Lindroth 1966). In the Nearctic Region, the genus is represented by 72 species. About 10 of them inhabit GSMNP (Ball and Bousquet 2001).

Life History

The species is hygrophilous and prefers margins of standing or running water with firm gravel and sand substrate and sparse or absent vegetation cover (Liebherr 1994). In the Park adults can be found under stones and among debris along edges of creeks and rivers in shady areas at low altitudes (400-500m).  Specimens from GSMNP were collected during June-September.


The species is widely distributed through eastern and central North America as far south as Florida and Mexico and north to Quebec, thence west to Colorado and Montana (Bousquet and  Larochelle 1993). At present it is known from only a few localities in GSMNP, but probably is more widely distributed and inhabits most low altitude areas  inside the Park. At Little River Gorge and at Little Pigeon River the species was taken in company with Nebria pallipes.

Conservation Concerns

Not under threat.

Habitat of  Agonum extensicolle


Locality records in GSMNP


Development of these pages was supported by grants from Discover Life in America and the National Science Foundation (DEB-0516311). Habitat photograph, Igor M. Sokolov, Louisiana State University.


Ball, G. E., and Y. Bousquet. 2001.  6. Carabidae Latreille, 1810. In: American Beetles. Vol.1. CRC Press. 32-132 pp.

Bousquet, Y., and  A. Larochelle. 1993. Catalogue of the Geadephaga (Col. Trachypachidae, Rhysodidae, Carabidae, incl. Cicindelini) of America north of Mexico. Entomological Society of Canada, Memoir No.167. 395 pp.

Liebherr, J. K. 1994. Identification of New World Agonum, review of the Mexican fauna, and description of Incagonum, new genus, from South America (Coleoptera: Carabidae: Platynini). J. New York Entomol. Soc. Vol.102. No 1:1-55.

Lindroth, C. H. 1966. The ground-beetles (Carabidae, excl.Cicindelinae) of  Canada and Alaska. Part 4. Opuscula Entomologica. Supplementum No.29. 409-648pp.

Posted 25 Sept. 2006, I. M. Sokolov, Louisiana State Arthropod Museum.

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