Three new species and DNA sequence data of the rare South American water beetle genus Adelphydraena Perkins, 1989 (Coleoptera: Hydraenidae) Author Perkins, Philip D. 0000-0001-8834-9052 Department of Entomology, Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138 USA. perkins @ oeb. harvard. edu; https: // orcid. org / 0000 - 0001 - 8834 - 9052 perkins@oeb.harvard.edu Author Ribera, Ignacio Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Maritim de la Barceloneta 37 - 49, 08003 Barcelona, Spain. ignacio. ribera @ ibe. upf-csic. es text Zootaxa 2020 2020-09-29 4858 1 35 52 journal article 8432 10.11646/zootaxa.4858.1.2 fa172759-c7a8-4682-b992-8871c155eb3a 1175-5326 4411485 22886812-4F5E-42E4-B8EA-5687BB483AA8 Adelphydraena orchymonti Perkins Figs 1 , 3 , 13 (habitus), 10 (aedeagus), 14 (map), 17–18 (habitat) Adelphydraena orchymonti Perkins 1989: 450 Differential diagnosis. The smallest member of the genus (ca. 1.24 mm ), differentiated from other Adelphydraena by the combination of small size, the non-chordate pronotum, the very small metaventral plaques ( Fig. 13 ), and the aedeagus ( Fig. 10 ). New collection records: Venezuela : T. F. Amazonas , Puerto Ayacucho ( 40km S), El Tobogan , Canocoromoto , 26Jan1989 , stream edge at upper shelter, collected by P. J. Spangler , R. A. Faitout , & C. B. Barr (1 NMNH ) . Amazonas prov. , 100m , Tobogan de la Selva , S Puerto Ayacucho , 24- 25.1.2004 , M. Balke ( 4 specimens , NMW , IBE ) ; one female used for DNA extraction and sequencing (specimen voucher MNCN-AI356). Amazonas prov. , Cerro Cuau env., 19.11. 2012 , 923 m a.s.l., 05°05’39.1’’ N , 67°27’41.4’’ W , F. Čiampor , Loc 30 ( 1 female , IBE ) . Used for DNA extraction and sequencing (specimen voucher IBE-AN711) . Remarks. The habitus images ( Figs. 3 , 13 ) and the aedeagus drawing ( Fig. 10 ) are of the specimen collected at El Tobogan, Canocoromoto.