Hemiosus

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Ecdysozoa
Cladus: Panarthropoda
Phylum: Arthropoda
Subphylum: Hexapoda
Classis: Insecta
Cladus: Dicondylia
Subclassis: Pterygota
Cladus: Metapterygota
Infraclassis: Neoptera
Cladus: Eumetabola
Cladus: Endopterygota
Superordo: Coleopterida
Ordo: Coleoptera
Subordo: Polyphaga
Infraordo: Staphyliniformia
Superfamilia: Hydrophiloidea

Familia: Hydrophilidae
Subfamilia: Hydrophilinae
Tribus: Berosini
Genus: Hemiosus
Species: H. tarsalis
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References

Clarkson, B.; Ferreira-jr., N. 2009: Three new species of Hemiosus Sharp (Coleoptera: Hydrophilidae) and new state records of Hemiosus fittkaui Oliva and H. moreirai d’Orchymont from Brazil. Zootaxa, 2139: 61–68. Abstract & excerpt
Oliva, A. 1994: A revision of the genus Hemiosus Sharp, 1882 in South America (Coleoptera: Hydrophilidae). Bulletin et Annales de la Société Royal Belge d’Entomologie, 130: 267–303. [not seen]
Oliva, A.; Short, A.E.Z. 2010: A remarkable new species of Hemiosus Sharp from Amazonian Peru (Coleoptera: Hydrophilidae). Koleopterologische rundschau, 80: 139–142. PDF