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 inornatus ( d'Orchymont , 1926) Helochares (s. str.) inornatus d'Orchymont , 1926: 235. Novochares inornatus ( d'Orchymont , 1926); Giron and Short 2021 : 205. Type material. Holotype : female from French Guiana ( "Passoura" ) deposited in IRNSB (not seen). Other material examined that has been previously identified as this species ( 3 exs. ). Brazil : Rio Sapio , Rio Solimoes , from water in canoe, 21.ii.1874 , [identified and labeled as Novochares inornatus by J. Balfour-Brown ] (1, USNM) . Paraguay : Sapucay , "WT Foster Collector", " Helochares (s.str.) sp., prob. Novochares inornatus , wait for males" [identification label by d'Orchymont ] ( 1 female , USNM) . Trinidad And Tobago : Trinidad , "Aug. Busck Collector" " Helochares (s.str.) prob. Novochares inornatus , wait for males" [identification label by d'Orchymont ] ( 1 female , USNM) . Remarks. d'Orchymont (1926) described N. inornatus from four female specimens (the holotype from French Guiana, and three others from Sao Paulo, Brazil). The species is described as large (9 mm) and dull black in color. At the time of its description, there were no other large, black species known from South America and it would have been obviously distinct. However, now that we know there are several large and dark species in South America that are essentially externally indistinguishable from each other, the fact that the type series is entirely female presents a problem. Indeed, d'Orchymont seems to have subsequently realized this issue: several female specimens in the USNM collection (from Trinidad and Paraguay) labeled by him as "prob. Novochares inornatus , wait for males". We note that Balfour-Browne (1939) identified specimens from Guyana and Brazil as N. inornatus . From Guyana (Upper Kutari River), he examined one "immature male", which he dissected and illustrated the aedeagus (fig. 4 in Balfour-Browne 1939 ). From Brazil (Amazonas: Rio Sappo, Rio Solimoes) he examined one male and two females. Based on the drawing, it seems likely that the specimens that Balfour-Browne examined are of what we have named here as N. duo sp. nov. However, there is no way to know if males identified by Balfour-Browne from Guyana and Brazil are conspecific with the type female from French Guiana. There are several species in French Guiana that match the size and color of N. inornatus : N. duo sp. nov., N. tectiformis , N. coya , and N. orchis sp. nov. Yet, there is no way at present (morphologically) to be sure which one the female type represents. Therefore, to better stabilize the nomenclature of the genus, we place the name N. inornatus as incertae sedis.