Family Trogossitidae - Bark-gnawing Beetles

Ostomatidae

Author of family is Latreille, 1802. Family name is from that of genus Trogosita, which is New Latin (Olivier, 1790), from Greek, combination of τρωγειν, gnaw, plus σιτοζ, grain (1).

Insects of Cedar Creek lists 64 North American species.

2-22 mm, most 5-15 mm

Antennae usually distinctive, ending in 3-segmented club, with those three segments enlarged on one side (2), here shown juxtaposed with the antennae of a carabid:

Most Bark-gnawing Beetles are cylindrical or slightly flattened, and with pronotum and elytra separated by a narrow "waist". The body is typically shiny (2). These tend to live under bark. See, for example, Temnoscheila and Tenebroides:

Some genera are elliptical and flattened with sculptured body, often dull (2). These tend to be associated with bracket fungi. See, for example, Thymalus:

"Although some species of Tenebroides are distinctive (e.g., T. collaris, T. obtusus) many are very similar and difficult to identify, especially from photographs. To maximize the likelihood of a species-level identification photographs of Tenebroides species should include 1) a clear dorsal shot showing the body outline and especially that of the pronotum; 2) a detail shot of the pronotum clearly showing the anterior and basal angles and the basal marginal bead; and 3) a detail shot of the antennal club showing the sensory areas." [M.C. Thomas, 2009]

Forests. Some groups found under bark, others found associated with bracket fungi.

Many are predatory on other beetles and their larvae.

Barron, J. R., 1971, A revision of the Trogositidae of America north of Mexico (Coleoptera: Cleroidea): Memoirs of the Entomological Society of Canada, v. 75, 1-143.

The Century Dictionary--entry for Trogosita (1)

White, pp. 208-209, fig. 86, plate 3 (2)

American Beetles, Vol. 2, Chapter 72 (3)