Three new genera of acidocerine water scavenger beetles from tropical South America (Coleoptera, Hydrophilidae, Acidocerinae) Author Giron, Jennifer C. https://orcid.org/0000-0002-0851-6883 Department of Ecology & Evolutionary Biology, and Division of Entomology, Biodiversity Institute, University of Kansas, Lawrence, KS 66045, USA entiminae@gmail.com Author Short, Andrew Edward Z. Department of Ecology & Evolutionary Biology, and Division of Entomology, Biodiversity Institute, University of Kansas, Lawrence, KS 66045, USA text ZooKeys 2018 2018-06-19 768 113 158 http://dx.doi.org/10.3897/zookeys.768.24423 journal article http://dx.doi.org/10.3897/zookeys.768.24423 1313-2970-768-113 399BCC3E9D6F4231870E05C79B9FD4B0 CB01CA30FFB4F96DFFA2FF86FFAEFFB6 1298776 Nanosaphes castaneus sp. n. Figs 15A-D ; 18D ; 19 Type material examined. Holotype (male) : " BRAZIL: Para : Rio Xingu/ Camp ( 52°22'W , 3°39'S )/ Altamira (ca 60km S.)/ 12 Oct 1986/ P. Spangler & O. Flint// Colln. #21, pond at 2nd/ palm grove on trail 1" (USNM). Paratypes (3): BRAZIL: Para : Rio Xingu, Camp ( 52°22'W , 3°39'S )/ Altamira (ca 60km S.)/ 12 Oct 1986/ P. Spangler & O. Flint (1, USNM); same data as holotype (2, USNM, SEMC). Differential diagnosis. Nanosaphes castaneus can be easily recognized by its smooth elytra (as opposed to rather coarsely punctate as in N. punctatus , compare Fig. 15A, B to Fig. 15E, F ), and the uniform brown coloration along the body (as opposed to having yellow pronotum and brown elytra (as in N. hesperus and N. tricolor , compare Fig. 15A-D to Fig. 16 ). Description. Body length 1.3-1.4 mm, width 0.8-0.9 mm. Body elongate oval, weakly convex, uniformly brown throughout (Fig. 15A, B ). Dorsal surface shallowly punctate . Posterior elevation of mesoventrite weakly carinate. Pubescence of ventral surface scanty. Aedeagus (Fig. 18C ) with basal piece 0.4-times the length of parameres; parameres longer than median lobe, with rounded apex; gonopore situated near apical third of median lobe. Etymology. Named in reference to the uniform brown coloration along the body, with the Latin word castaneus meaning brown, of the color of chestnuts. Distribution. Brazil ( Para ). Only known from one locality. See Fig. 19 . Biology. In referencing Spangler's original field notes, these specimens were collected in forested pond.