Introduction. The name of each listed species is followed by up to five sources that report the species as occurring in Michigan. Sources in all upper-case letters refer to specific insect collections: MSU-ARC refers to material held by the Michigan State University Arthropod Research Collection (data provided by G. Parsons). All others refer to collection data extracted from the Symbiota Collections of Arthropods Network (SCAN) database online at See the Methods page for a list of abbreviations and associated collections.

Species names preceded by a single '?' are considered probable (for occurring in Michigan) but uncertain records. Those preceded by '??' are considered possible but unlikely to occur in Michigan. Species that are fully accepted as having valid Michigan records are unmarked. Species reported in the literature that we consider to be erroneous Michigan records are in a separate list following the others.

The genus long known as Trox has been divided into several genera by Nikolajev (2016). GBIF follows the new classification whereas BugGuide does not. In this case we are following the newer classification.


2 subfamilies, 3 genera, 17 species

Subfamily Omorginae

Omorgus asper (LeConte, 1854): Ruesink and Parsons (2024), MSU-ARC

Omorgus scabrosus (Palisot de Beauvois, 1805): Ruesink and Parsons (2024), MSU-ARC

Omorgus suberosus (Fabricius, 1775): Townsend (1889), MSU-ARC; Vaurie (1955) says it occurs in "all of the United States except the Pacific northwest and northern New England", but does not list specific localities

Subfamily Troginae

Glyptotrox foveicollis (Harold, 1872): Vaurie (1955), Andrews (1923); BugGuide still uses Trox for this and the next two species

Glyptotrox hamatus (Robinson, 1940): Vaurie (1955), MSU-ARC; Vaurie (1955) implies she examined MI specimens but did not so state explicitly

Glyptotrox spinulosus spinulosus (Robinson, 1940): Zidek (2013), Vaurie (1955), MSU-ARC

Trox aequalis Say, 1831: Hubbard and Schwarz (1878), Vaurie (1955), MSU-ARC; Vaurie (1955) implies she examined MI specimens but did not so state explicitly

Trox atrox LeConte, 1854: Zidek (2013), Vaurie (1955), Downie and Arnett (1996), MSU-ARC

Trox capillaris Say, 1824: Vaurie (1955), MSU-ARC

Trox laticollis LeConte, 1854: Ruesink and Parsons (2024), MSU-ARC; very rarely collected, known from scattered locations from New England to Arkansas

Trox robinsoni Vaurie, 1955: Vaurie (1955), Zidek (2013)

Trox scaber (Linnaeus, 1767): Bezanson and Floate (2019), Hubbard and Schwarz (1878), Downie and Arnett (1996), MSU-ARC

Trox sordidus LeConte, 1854: Hubbard and Schwarz (1878), Ruesink and Parsons (2024), MSU-ARC; known from ON and nearby states of IN & OH in Vaurie (1955)

Trox striatus Melsheimer, 1845: Ruesink and Parsons (2024), MSU-ARC; rarely collected, associated with owl droppings

Trox tuberculatus (DeGeer, 1774): Ruesink and Parsons (2024), MSU-ARC; known also from N. Indiana

Trox unistriatus Palisot de Beauvois, 1805: Vaurie (1955), Andrews (1923), Hatch (1924), Hubbard and Schwarz (1878), MSU-ARC; Vaurie (1955) implies she examined MI specimens but did not so state explicitly

Trox variolatus Melsheimer, 1845: Vaurie (1955), Bezanson and Floate (2019), Townsend (1889), Downie and Arnett (1996), MSU-ARC

The following species was also reported from Michigan, but we consider it to be adventive, a misidentification or other error:

Subfamily Troginae

Glyptotrox terrestris (Say, 1825): Townsend (1889) as Trox terrestris Say; an east coast & SE sp.; should not be in MI

This family list was last updated: March 10, 2023