Revision of the Neotropical water scavenger beetle genus Novochares Giron & Short (Coleoptera, Hydrophilidae, Acidocerinae) Author Short, Andrew Edward Z. https://orcid.org/0000-0002-7467-7116 Department of Entomology & Nematology, University of Florida, Gainesville, FL, 32611, USA aezshort@ku.edu Author Giron, Jennifer C. https://orcid.org/0000-0002-0851-6883 Natural Science Research Laboratory, Museum of Texas Tech University, Lubbock, TX 79409, USA text ZooKeys 2023 2023-07-20 1171 1 112 http://dx.doi.org/10.3897/zookeys.1171.104142 journal article http://dx.doi.org/10.3897/zookeys.1171.104142 1313-2970-1171-1 267D0D4559CA4A18A08034768E652607 7559C2D42DE85144AEFFC98A16172F97 Novochares geminus sp. nov. Figs 15G, H , 16B Type material. Holotype (male) : "BRAZIL: Mato Grosso do Sul/ -20.72281 , -55.69127 ; 225 m/ Aquidauana (c. 27 m S) on/ MS-174; leg. Hamada & team;/27.vi.2018; seepage & debris nr. stream margin; BR18-0627-01E" (INPA). Paratypes (2 exs.): Brazil: Mato Grosso do Sul : Same data as holotype (2, SEMC, including DNA Voucher SLE2092). Differential diagnosis. Among species of the Novochares punctatostriatus species group, N. geminus is one of three species that lack distinct rows of elytral serial punctures, the others being N. spangleri and N. triangularis . Those two species can be separated by the shape of the forked projections of the median lobe, which are broader and swollen at the apex (Fig. 15 E, F, I ), while they are slender and not expanded apically in N. geminus (Fig. 15G, H ). Description. Size and form : Body length 5.9-6.0 mm. Coloration : Dorsal surfaces dark brown, with slightly paler margins of pronotum and elytra. Head : Maxillary palps as long as to slightly longer than width of head, uniformly orange in color. Thorax : Elytra without defined rows of serial punctures, each with one dorsal and a few lateral sparse rows of systematic punctures. Prosternum medially weakly and broadly convex. Posterior elevation of mesoventrite transverse, low, and blunt. Aedeagus : (Fig. 15G, H ) lateral projection on apical region of outer margin of each paramere pointed; at closest point, dorsal inner margins of parameres separated by distance nearly 1/2 greatest width of a paramere; dorsal plate of median lobe with small denticle on each lateral margin, proximal to base of fork; arms of dorsal plate of median lobe parallel, diverging at apex; each arm parallel sided, with inner margins sinuate, apex rounded and pointing outwards; notch between arms at base nearly as broad as base of an arm; ventral plate of median lobe lightly sclerotized, at widest point nearly as wide as dorsal plate of median lobe, apically acuminate, apex nearly reaching apex of arms of dorsal plate, ventral surface of each side medially sharply elevated forming narrow medial slit; basal piece 0.35 x length of a paramere. Etymology. Geminus (L.), meaning twin, in reference to the split apex of the dorsal plate of the median lobe. Distribution. Brazil (Mato Grosso do Sul) (Fig. 16B ). Habitat. The only known series was taken from the margin of a rocky stream, where a seep was flowing over large rocks.