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Coleoptera of Great Smoky Mountains National Park Species Pages

Family Leiodidae

            Tribe Colonini

 Colon (Striatocolon) thoracicum Horn

Description and Taxonomy

The genus is the only N. American member of the subfamily (and tribe) Coloninae and  may be diagnosed from other Leiodidae by a combination of the following characters: head without occipital carina or crest, 5-5-5 tarsal formula in both sexes, 11-segmented antenna with 3-5-segmeneted (4-segemented in species from  the Appalachian region) club, 8th antennomere not smaller than 7th and 9th and females with four and males with five visible abdominal sternites (Peck & Stephan 1996). The latter character is especially important for practical identification purposes, since inspection of male genitalia is essential for identification or confirmation and males in Colon occur as majors and minors, the latter being female-like in appearance (except the number of visible abdominal sternites). Five subgenera and 40 species are known in N. America (Peck & Stephan 1996), with discovery of about a dozen species in four subgenera possible in the southern Appalachians. Seven species have been found so far in GSMNP (Tishechkin 2007). This subgenus includes a single species diagnosed by protarsi dilated only in males, double pronotal puncturation and the presence of more or less distinct elytral striae (Peck & Stephan 1996).  

Life History

Life history and larvae of the genus are still unknown (Peck & Stephan 1996). Associations with with subterranean fungi or molds is suspected, but so far no evidence confirming this biology is forthcoming. Beetles are occasionally collected by forest litter sifting and pitfall trapping and more regularly by consistent passive collecting methods such as flight intercept and Malaise trapping and car netting (Peck & Stephan 1996). They are known to perform dispersal flights two to three hours before sunset during favorable weather conditions and may be found on low vegetation or on the wing during such flight periods. The GSMNP specimens were collected by Malaise trapping and forest litter sifting at 625-1505 m of elevation.


Widely distributed in eastern and central N America, from Michigan and Quebec to Oklahoma and Louisiana (Peck & Stephan 1996, Tishechkin, unpublished).

Conservation Concerns

Not under threat.


Locality records in GSMNP.


Development of these pages was supported by grants from Discover Life in America and the National Science Foundation (DEB-0516311).


Peck, S. B. and K. Stephan. 1996. Revision of the genus Colon Herbst (Coleoptera: leiodidae: Coloninae) of North America. Canadian Entomologist 128: 667-741.


Posted 15 August 2007, A. K. Tishechkin, Louisiana State Arthropod Museum.

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