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.
HYDROPHILIDAE
3 subfamilies, 8 tribes, 21 genera, 82 species
Subfamily Chaetarthriinae
Chaetarthria atra (LeConte, 1863): Haack and Ruesink (2020), Miller (1974), MSU-ARC
Chaetarthria pallida (LeConte, 1861): Miller (1974), Willson (1970), Bright (2015), Hubbard and Schwarz (1878), MSU-ARC
Subfamily Hydrophilinae
Tribe Anacaenini
Anacaena lutescens (Stephens, 1829): Haack and Ruesink (2020), Bright (2015), LeConte (1878), Hubbard and Schwarz (1878), MSU-ARC; authorities disagree on whether what we have in MI is A. lutescens, A. limbata (Fabricius) or an undescribed species very similar to these two.
Crenitis digesta (LeConte, 1855): Bright (2015), Wolcott (1909), Hubbard and Schwarz (1878), MSU-ARC
Paracymus confluens Wooldridge, 1966: Wooldridge (1966), Smetana (1988), Bright (2015), Downie and Arnett (1996), MSU-ARC
?Paracymus confusus Wooldridge, 1966: Bright (2015), Downie and Arnett (1996); Willson (1970) says this sp. not recorded from MI
Paracymus despectus (LeConte, 1863): Wooldridge (1966), Bright (2015), Hatch (1924), Downie and Arnett (1996), MSU-ARC
Paracymus subcupreus (Say, 1825): Bright (2015), Hatch (1924), Andrews (1923), Hubbard and Schwarz (1878), MSU-ARC; very common throughout MI (Willson, 1970)
Tribe Berosini
Berosus aculeatus LeConte, 1855: Smetana (1988), Bright (2015), Downie and Arnett (1996), MSU-ARC
Berosus fraternus LeConte, 1855: Bright (2015), Downie and Arnett (1996), MSU-ARC
?Berosus infuscatus LeConte, 1855: Bright (2015), Andrews (1916), Andrews (1923), FMNH:FMNHINS; Charity Island specimens in UMMZ:UMMZI & SI:NMNH; however, a southern sp. that should not occur in MI
Berosus peregrinus (Herbst, 1797): Bright (2015), Schwarz (1876), Hatch (1924), Downie and Arnett (1996), MSU-ARC
Berosus sayi Hansen, 1999: Bright (2015), Andrews (1923), Downie and Arnett (1996), Hubbard and Schwarz (1878), MSU-ARC
Berosus stylifer Horn, 1873: Smetana (1988), Bright (2015), MSU-ARC
Tribe Hydrobiusini
Sperchopsis tessellata (Ziegler, 1844): Bright (2015), Spangler (1961), Andrews (1923), Hubbard and Schwarz (1878), MSU-ARC
Tribe Hydrophilini
Cymbiodyta acuminata Fall, 1924: Smetana (1974), Willson (1970), Bright (2015), MSU-ARC
Cymbiodyta blanchardi Horn, 1890: Willson (1970), Andrews (1916), Hatch (1924), Bright (2015), MSU-ARC
Cymbiodyta chamberlaini Smetana, 1974: Smetana (1974), Smetana (1988), Bright (2015), Downie and Arnett (1996)
Cymbiodyta minima Notman, 1919: Smetana (1974), Willson (1970), Bright (2015), Downie and Arnett (1996), MSU-ARC
Cymbiodyta semistriata (Zimmermann, 1869): Smetana (1974), Bright (2015), Downie and Arnett (1996)
Cymbiodyta toddi Spangler, 1966: Smetana (1974), Bright (2015), Willson (1970), Downie and Arnett (1996), MSU-ARC
Cymbiodyta vindicata Fall, 1924: Smetana (1974), Bright (2015), Willson (1970), Downie and Arnett (1996), MSU-ARC
?Enochrus blatchleyi (Fall, 1924): Bright (2015), Downie and Arnett (1996); MI record needs confirmation
Enochrus cinctus (Say, 1824): Gunderson (1978), Bright (2015), Andrews (1916), Hubbard and Schwarz (1878), MSU-ARC
Enochrus consors (LeConte, 1863): Gunderson (1978), Willson (1970), Bright (2015), Schwarz (1876), Hubbard and Schwarz (1878); uncommon
Enochrus consortus Green, 1946: Gunderson (1978), Willson (1970), Bright (2015), Downie and Arnett (1996), MSU-ARC
Enochrus diffusus (LeConte, 1855): Bright (2015), Ruesink and Parsons (2023), MSU-ARC; mostly a western sp., very scarce in the east
Enochrus fimbriatus (Melsheimer, 1844): Gunderson (1978), Andrews (1923), Hubbard and Schwarz (1878), Bright (2015), MSU-ARC
Enochrus hamiltoni (Horn, 1890): Gunderson (1978), Bright (2015), Andrews (1916), Downie and Arnett (1996), MSU-ARC; one of the MSU specimens is from Andrews Charity Island collection & was misidentified by him as Cymbiota blanchardi
Enochrus ochraceus (Melsheimer, 1844): Haack and Ruesink (2020), Gunderson (1978), Bright (2015), Hubbard and Schwarz (1878), MSU-ARC; extremely common throughout MI (Willson, 1970)
Enochrus pygmaeus nebulosus (Say, 1824): Gunderson (1978), Bright (2015), Hatch (1924), Hubbard and Schwarz (1878), MSU-ARC
Enochrus sayi Gundersen, 1977: Gunderson (1978), Bright (2015), Downie and Arnett (1996), MSU-ARC
Helocombus bifidus (LeConte, 1855): Haack and Ruesink (2020), Bright (2015), Willson (1970),Hubbard and Schwarz (1878), MSU-ARC
Hydrobius fuscipes (Linnaeus, 1758): Haack and Ruesink (2020), Bright (2015), Downie and Arnett (1996), Hubbard and Schwarz (1878), MSU-ARC; extremely common throughout MI (Willson, 1970)
Hydrochara obtusata (Say, 1823): Smetana (1980), Bright (2015), Downie and Arnett (1996), Willson (1970), Hubbard and Schwarz (1878), MSU-ARC
Hydrochara simula Hilsenhoff & Tracy, 1982: Hilsenhoff and Tracy (1982), Bright (2015), Downie and Arnett (1996)
Hydrochara soror Smetana, 1980: Smetana (1980), Bright (2015), Downie and Arnett (1996), MSU-ARC
Hydrophilus ovatus Gemminger & Harold, 1868: Short and McIntosh (2014), Bright (2015), Peck and Thomas (1998), Hubbard and Schwarz (1878), MSU-ARC
Hydrophilus triangularis Say, 1823: Short and McIntosh (2014), Bright (2015), Downie and Arnett (1996), Hubbard and Schwarz (1878), MSU-ARC
Limnohydrobius melaenus (Germar, 1824): Haack and Ruesink (2020), Bright (2015), Downie and Arnett (1996), Hatch (1924), MSU-ARC; used to be in the genus Hydrobius
Tropisternus blatchleyi modestus d'Orchymont, 1938: Willson (1970), Bright (2015), MSU-ARC
Tropisternus columbianus Brown, 1931: Willson (1970), Bright (2015), MSU-ARC
Tropisternus glaber (Herbst, 1797): Willson (1970), Bright (2015), Andrews (1923), Hubbard and Schwarz (1878), MSU-ARC
Tropisternus lateralis nimbatus (Say, 1823): Bright (2015), Andrews (1923), Hubbard and Schwarz (1878), Downie and Arnett (1996), MSU-ARC
Tropisternus mixtus (LeConte, 1855): Willson (1970), Bright (2015), Andrews (1923), Hatch (1924), Hubbard and Schwarz (1878), MSU-ARC; a very common species (Willson, 1970)
Tropisternus natator d'Orchymont, 1938: Willson (1970), Peck and Thomas (1998), Bright (2015), MSU-ARC; common throughout the lower peninsula (Willson, 1970)
Tribe Laccobiini
Laccobius agilis (Randall, 1838): Cheary (1971), Bright (2015), Hatch (1924), Hubbard and Schwarz (1878), MSU-ARC
Laccobius arenarius Cheary, 1971: Cheary (1971), Willson (1970), MSU-ARC
?Laccobius cinereus columbianus Miller, 1965: Downie and Arnett (1996), Bright (2015); needs confirmation
Laccobius minutoides d'Orchymont, 1942: Cheary (1971), Willson (1970), Bright (2015), MSU-ARC
Laccobius nevadensis magnus Cheary, 1971: Cheary (1971)
Laccobius spangleri Cheary, 1971: Cheary (1971), Willson (1970), Bright (2015), MSU-ARC
?Laccobius truncatipennis Miller, 1965: Bright (2015); needs confirmation
Subfamily Sphaeridiinae
Tribe Coelostomatini
Phaenonotum exstriatum (Say, 1835): Smetana (1978), Bezanson and Floate (2019), Willson (1970), Hubbard and Schwarz (1878), MSU-ARC
Tribe Megasternini
Cercyon analis (Paykull, 1798): Smetana (1978), Andrews (1923), Hubbard and Schwarz (1878), MSU-ARC
Cercyon assecla Smetana, 1978: Smetana (1978), Bezanson and Floate (2019), Downie and Arnett (1996)
Cercyon cinctus Smetana, 1978: Smetana (1978), Downie and Arnett (1996)
Cercyon connivens Fall, 1924: Smetana (1978), Downie and Arnett (1996)
Cercyon erraticus Smetana, 1978: Smetana (1978), Downie and Arnett (1996)
Cercyon haemorrhoidalis (Fabricius, 1775): Smetana (1978), Bezanson and Floate (2019), Wassmer (2020), Hubbard and Schwarz (1878), MSU-ARC
Cercyon herceus herceus Smetana, 1978: Smetana (1978)
Cercyon lateralis (Marsham, 1802): Smetana (1978), Bezanson and Floate (2019), Downie and Arnett (1996), MSU-ARC
Cercyon marinus Thomson, 1853: Smetana (1978), Bezanson and Floate (2019), Bright (2015), Downie and Arnett (1996), MSU-ARC
Cercyon mendax Smetana, 1978: Smetana (1978), Bright (2015), Downie and Arnett (1996)
Cercyon minusculus Melsheimer, 1844: Smetana (1978), Bezanson and Floate (2019), Downie and Arnett (1996), MSU-ARC
Cercyon nigriceps (Marsham, 1802): Smetana (1978), Bezanson and Floate (2019), Hubbard and Schwarz (1878), Downie and Arnett (1996), MSU-ARC
Cercyon occallatus (Say, 1825): Smetana (1978), Downie and Arnett (1996), Hubbard and Schwarz (1878), MSU-ARC
Cercyon praetextatus (Say, 1825): Smetana (1978), Bezanson and Floate (2019), Andrews (1923), Hubbard and Schwarz (1878), MSU-ARC
Cercyon pygmaeus (Illiger, 1801): Smetana (1978), Bezanson and Floate (2019), Wassmer (2020), Hatch (1924), MSU-ARC
Cercyon quisquilius (Linnaeus, 1760): Smetana (1978), Bezanson and Floate (2019), Wassmer (2020), Downie and Arnett (1996), MSU-ARC
Cercyon roseni Knisch, 1922: Smetana (1978), Bright (2015), Downie and Arnett (1996)
?Cercyon terminatus (Marsham, 1802): Wassmer (2020); a palearctic sp. previously known from nearby states, MI record needs confirmation
Cercyon unipunctatus (Linnaeus, 1758): Smetana (1978), Bezanson and Floate (2019), Hubbard and Schwarz (1878), Downie and Arnett (1996), MSU-ARC
Cryptopleurum americanum Horn, 1890: Wassmer (2020), Willson (1970), MSU-ARC
Cryptopleurum minutum (Fabricius, 1775): Smetana (1978), Bezanson and Floate (2019), Wassmer (2020), Andrews (1923), MSU-ARC
Cryptopleurum subtile Sharp, 1884: Smetana (1978), Bezanson and Floate (2019), Wassmer (2020), Downie and Arnett (1996)
Cryptopleurum vagans LeConte, 1855: Smetana (1978), Hubbard and Schwarz (1878), Downie and Arnett (1996)
Oosternum pubescens (LeConte, 1855): Willson (1970), MSU-ARC
Tectosternum naviculare (Zimmermann, 1869): Smetana (1978), Hubbard and Schwarz (1878), Downie and Arnett (1996)
Tribe Sphaeridiini
Sphaeridium bipustulatum Fabricius, 1781: Smetana (1978), Bezanson and Floate (2019), Wassmer (2020), Downie and Arnett (1996), MSU-ARC
Sphaeridium lunatum Fabricius, 1792: Smetana (1978), Bezanson and Floate (2019), Wassmer (2020), Downie and Arnett (1996)
Sphaeridium scarabaeoides (Linnaeus, 1758): Smetana (1978), Bezanson and Floate (2019), Wassmer (2020), Andrews (1923), MSU-ARC
The following species were also reported from Michigan, but we consider them to be adventive, misidentifications or other errors:
Subfamily Hydrophilinae
Tribe Hydrophilini
Cymbiodyta rotunda (Say, 1825): Downie and Arnett (1996); an eastern sp.; should not be in MI
Enochrus carinatus fucatus (Horn, 1873): Andrews (1923) as Philhydrus fucatus Horn; this SW sp. does not occur in MI
Helochares maculicollis Mulsant, 1844: Andrews (1916); H. maculicollis is more southern, should not occur in MI; 2 Andrews specimens from Charity Islands in MSU collection IDed as this species are actually Enochrus
Tropisternus sublaevis (LeConte, 1855): Andrews (1916), Andrews (1923); a southwestern sp. that does not occur in MI, he probably had T. columbianus
Subfamily Sphaeridiinae
Tribe Megasternini
Cryptopleurum crenatum (Kugelann, 1794): Wassmer (2014), Wassmer (2020); a palearctic sp. that Smetana (1978) says does not occur in N.A.
This family list was last updated: December 28, 2022