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Coleoptera of Great Smoky Mountains National Park Species Pages

Family Histeridae

            Tribe Histerini

 Margarinotus (Ptomister) egregius (Casey)

Description and Taxonomy

Length 5..5-7.5 mm. The genus belongs to the tribe Histerini characterized by the presence of expanded prosternal lobe, free labrum, antennal cavities situated under anterior angles of pronotum, dentate protibiae with straight protarsal furrow, antennal club with annuli not V-shaped, mesosternum without median projection and prosternal base without emargination (Kryzhanovskij & Reichardt 1976, Kovarik & Caterino 2000).  Five-six genera of Histerini are known in N America (Kovarik & Caterino 2000, Bousquet & Lapalante 2006), and three present in the GSMNP. Margarinotus is externally diverse genus diagnosed primarily by several characters of male genitalia.  However, most of the species (all in the East and GSMNP) may be recognized by emarginate outline of the anterior margin of mesosternum and complete inner subhumeral striae on elytra. There are 29 described species in the genus in N America, seven of which are found in the GSMNP. This species may be diagnosed by complete marginal stria of pronotum, the presence of  two lateral pronotal striae, absence of the basal fragments 5th dorsal striae, sparse puncturation of propygydium and pygidium and interrupted lateral metasternal stria. Denser puncturation of pygidia and the presence of subapical elytral depression allows to separate this species from its most similar congener, M. immunis.

Life History

 The species is associated, at least facultatively, with groundhog burrows, also it has been collected on carrion and decaying vegetation (Bousquet & Lapalante 2006).  It was collected in the GSMNP by flight intercept traps at 620-1515 m of elevation.


 Widespread in eastern N America  from Manitoba and Nova Scotia to Florida (Bousquet & Lapalante 2006).

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).


Bousquet, Y. and S. Laplante. 2006.  Coleoptera Histeridae. The insects and arachnids of Canada. Part 24. NRC Research press, Ottawa. 485 pp.

Kovarik, P.W. and M. S. Caterino.  2000. Histeridae. Pp. 212-227 in: Arnett, R. H. and M. C. Thomas (eds.) American beetles. Vol. 1. CRC Press, Boca Raton  - London - New York - Washington.

Kryzhanovskij, O. L. and A. N. Reichardt. 1976. Histeroidea. fauna of the USSR. Vol. V (4). Nauka: Moscow - Leneingrad. 433 pp.


 Posted June 2007, A. K. Tishechkin, Louisiana State Arthropod Museum.

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