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 https://scan-bugs.org/. 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.

In his genus-level revision of the Phalacridae of the world Gimmel (2013) chose to not assign genera to the two previously recognized subfamilies, even though his analyses supported the traditional separation. We follow his generic classification here. By the previous classification (as in Bouchard, 2011) all known Michigan species would be placed in the subfamily Phalacrinae.

PHALACRIDAE

1 subfamily, 5 genera, 12 species

Subfamily Phalacrinae

Acylomus ergoti Casey, 1890: Gimmel (2011b), Gimmel (2013), Hubbard and Schwarz (1878), Downie and Arnett (1996), MSU-ARC

??Acylomus piceus Casey, 1890: Hatch (1924); a poorly known sp. but reported from IN. MI record needs confirmation

Acylomus pugetanus Casey, 1916: Gimmel (2011b), Majka et al. (2008)

Olibrus semistriatus LeConte, 1856: Haack and Ruesink (2020), Hatch (1924), Downie and Arnett (1996), MSU-ARC

Olibrus vittatus LeConte, 1868: Ruesink and Parsons (2023), MSU-ARC

Phalacrus americanus Guillebeau, 1894: Gimmel (2011b)

Phalacrus politus Melsheimer, 1844: Gimmel (2011b), Hubbard and Schwarz (1878), Downie and Arnett (1996), MSU-ARC

Phalacrus vicinus Guillebeau, 1894: Gimmel (2011b)

Stilbus apicalis (Melsheimer, 1844): Andrews (1923), Hatch (1924), Hubbard and Schwarz (1878), IPSB (1925), MSU-ARC

Stilbus nitidus (Melsheimer, 1844): Hubbard and Schwarz (1878), Ruesink and Parsons (2023), MSU-ARC

Stilbus quadrisetosus Casey, 1916: Gimmel (2011b), Leng (1920), Downie and Arnett (1996)

Xanthocomus attenuatus (Casey, 1890): Gimmel (2011a), Gimmel (2011b), Gimmel (2013)

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

Subfamily Phalacrinae

Neolitochrus immaculatus (Casey, 1890): Hubbard and Schwarz (1878) as Litochrus immaculatus Zimm.; an east coast sp. that should not occur in MI

This family list was last updated: February 10, 2023