Revision of the neotropical water scavenger beetle genus Guyanobius Spangler, 1986 (Coleoptera: Hydrophilidae: Chaetarthriini)

The genus Guyanobius Spangler, 1986 is revised and expanded. Two species, Guyanobius queneyi sp. n. (French Guiana, Suriname) and Guyanobius lacuniventris sp. n. (Venezuela), are described as new and the two existing species, Guyanobius adocetus Spangler, 1986 and Guyanobius simmonsorum Spangler, 1990, are redescribed. Prior records of G. adocetus from Suriname were erroneous and actually refer to G. queneyi sp. n. All known species of Guyanobius were collected in leaf packs in small forest streams. The discovery of the genus in the Venezuelan Andes adds a remarkable 1200 km westward extension to its known range. Diagnostic characters are illustrated and a key to species is presented.