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Coleoptera of Great Smoky Mountains National Park Species Pages

    Family Carabidae  

        Tribe Harpalini

 Trichotichnus  (s.str.) dichrous  (Dejean)

Description and Taxonomy

Length 9-11mm. This medium-sized Trichotichnus species can be separated  from other harpaline species in the Park by its color pattern, the presence of clypeo-ocular lines (prolongation of frontal foveae towards eyes) on the frons, and glabrous, strongly iridescent elytra with only one setigerous dorsal puncture (sometimes lacking) on each elytron . From the similar Trichotichnus species it may be distinguished by the form of the pronotum; with broad evenly rounded sides and obvious deplanation towards the posterior angles (Lindroth 1968). In the Nearctic Region, the genus is represented by 4 species, all of them inhabiting the Smokies (Ball and Bousquet 2001).

Life History

The species is comparatively xerophilous and in GSMNP occurs in xeric oak and mixed pine-oak forests that have been disturbed during their recent histories. Adults can be found beneath rocks or among leaves in litter at low altitudes (300-500m).  Specimens from GSMNP were collected during July-September. The species may be taken at  mercury vapor lights.


Widely distributed through eastern North America as far south as Florida and Texas and north to Vermont and  south Ontario (Bousquet and Larochelle 1993). The species is known from few localities in GSMNP, but probably is distributed wider in appropriate habitats at low elevations. 

Conservation Concerns

Not under threat.

Habitat of  Trichotichnus dichrous.



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.

Lindroth, C.H. 1968. The ground-beetles (Carabidae, excl.Cicindelinae) of  Canada and Alaska. Part 5. Opuscula Entomologica. Supplementum No.33. 649-944pp.

Posted 8 Dec. 2006, I. M. Sokolov, Louisiana State Arthropod Museum.

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