Three additional new genera of acidocerine water scavenger beetles from the Guiana and Brazilian Shield regions of South America (Coleoptera, Hydrophilidae, Acidocerinae)

Abstract. Recent study of the water scavenger beetle subfamily Acidocerinae in the Neotropical region has uncovered numerous undescribed species that are not able to be placed in existing genera. Here, we describe three new genera to accommodate 17 of these new species from South America: Aulonocharesgen. nov. for Aulonochareslingulatussp. nov. (French Guiana, Suriname), Aulonocharesnovoairensissp. nov. (Brazil), and Aulonocharestubulussp. nov. (Brazil, Guyana, Suriname, Venezuela); Ephydrolithusgen. nov. for Ephydrolithushamadaesp. nov. (Brazil), Ephydrolithusminorsp. nov. (Brazil), Ephydrolithusogmossp. nov. (Brazil), Ephydrolithusspiculatussp. nov. (Brazil), and Ephydrolithustelisp. nov. (Brazil); and Primocerusgen. nov. for Primoceruscuspidissp. nov. (Venezuela), Primocerusgigassp. nov. (Venezuela), Primocerusneutrumsp. nov. (Guyana, Suriname, Venezuela), Primocerusocellatussp. nov. (Venezuela), Primoceruspetilussp. nov. (Brazil), Primoceruspijiguaensesp. nov. (Venezuela), Primocerusmaipuresp. nov. (Venezuela), Primocerussemipubescenssp. nov. (Guyana), and Primocerusstriatolatussp. nov. (Suriname). The genus Ephydrolithusgen. nov. is currently known to be restricted to seepages in the mountainous regions of the Brazilian Shield. Aulonocharesgen. nov. and Primocerusgen. nov. are both currently only known from the Guiana Shield, though widespread in that region where they are associated with streams and seeps. We present differential diagnoses, maps, habitat details, and illustrations of all new genera and species here described.