Revision of the Neotropical water scavenger beetle genus Quadriops Hansen, 1999 (Coleoptera, Hydrophilidae, Acidocerinae)

Abstract. The genus Quadriops Hansen, 1999 is revised and redescribed. The genus is found to contain six species, including two that are here described as new: Quadriops clusia sp. n. (Brazil, Guyana, Suriname) and Q. acroreius sp. n. (Suriname, French Guiana). Two species are found to be junior subjective synonyms of Q. depressus Hansen, 1999: Q. amazonensis García, 2000, syn. n. and Q. politus Hansen, 1999, syn. n. The male of Q. similaris Hansen, 1999 is described for the first time. New records are provided for Q. dentatus Hansen, 1999, Q. reticulatus Hansen, 1999, and Q. similaris. All species are described and illustrated in detail. Most species are confirmed as having a terrestrial way of life, with several species being found in rotten fruits, sap flows, and dead wood. Furthermore, we discuss ecological trends of the species given their collecting information.