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Coleoptera of Great Smoky Mountains National Park Species Pages

Family Histeridae

            Tribe Acritini

 Acritus acaroides Marseul

Description and Taxonomy

Length 0.9-1.1 mm. The genus belongs to the tribe Acritini, which is characterized by tiny compact oval bodies, lack of a prosternal lobe, four-segmented hind tarsi and sclerotized basal areas of antennal clubs (Kovarik & Caterino 2000). Together with the tribe Bacaniini, they form an informal group called "Microhisteridae," distinguished by their tiny body sizes (extremely rarely approaching 2 mm maximum length) and compact short elliptic body shapes. Two genera of acritines, Acritus and Aeletes, are known from GSMNP. Acritus may be distinguished by the lack of lateral striae on the clypeus and presence of a small, but distinct scutellum. Acritus acaroides differs from the other congener in the park, A. exiguus, by its convex body shape, the presence of longitudinal rugose microsculpture in apical halves of elytra and a distinct row of punctures along the basal margin of the pronotum.

Life History

The park record represents rather atypical natural history information for the species, i.e. collection under a grass clump in a high montane grassland. The limited natural history information available indicates connections with lowland hardwood forests, often in floodplains and known from flood debris and litter atop beaver lodges (Tishechkin, unpublished).

Distribution

Known from Eastern North America, but the exact distribution is poorly documented and the species is rare in collections. It is not reported from Canada (Bousquet & Laplante 2006), and is more regularly collected in the southeast, from east Texas to South Carolina (Peck & Thomas 1998, Tishechkin, unpublished). This species is known from GSMNP from a single highland (1750 m) locality, Andrews Bald.

Conservation Concerns

Not under threat.

Locality records in GSMNP.

Acknowledgements

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

References

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.

Peck, S. B and M. C. Thomas. 1998. A distributional checklist of the beetles (Coleoptera) of Florida. Arthropods of Florida. Volume 16. Florida Dept. of Agriculture and Consumer Services, Gainesville. 180 pp.

 Posted 13 August 2007, A. K. Tishechkin, Louisiana State Arthropod Museum.

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