Taxonomy of Central American water beetles in the genus Hydrochus Leach, 1817 (Coleoptera: Hydrochidae) Author Perkins, Philip D. text Zootaxa 2021 2021-05-21 4974 3 459 503 journal article 6214 10.11646/zootaxa.4974.3.2 5b4eaeb3-5722-4021-84ad-125ccd80855f 1175-5326 4777839 1BD6220B-7540-4A12-B3D2-5EDC1A3B7DD8 Hydrochus bernardi Makhan Figs. 1 , 20 , 41 Hydrochus bernardi Makhan 1994: 42 . Originally described from Mexico . The following are new locality data records from Costa Rica and Mexico . Material examined (44) : Costa Rica : 16 m . S. La Cruz , 13.vii.1965 , leg. Paul J. Spangler (21 NMNH ) . Mexico : Chiapas , Mpio , Ángel Albino Corzo , Jaltenango , 16-Jan-2012 , 15°52’15”N , 92°43’26” W , Trampa Luz , D. Reynoso col. (1 IEXA ) ; Guerrero , 3.7 mi. E. Marquelia , 10.vii.1974 , leg. Clark , Murray , Ashe , Schaffner (1 TAMU ) ; 7 KM DE IXTAPA-PTO. LA SALITRERA, 28.vi.1986 , leg. J. Bueno , S. Santiago (2 UNAM ) ; Nayarit , Acaponeta , 15.viii.1960 , leg. E. S. Ross , D. C. Rentz , P. H. Arnaud Jr. (1 CAS ) ; San Blas , 17-21.ix.1953 , leg. B. Malkin (1 CAS ) ; Sinaloa , 7 mi. N. Rosario , 24.vii.1963 , leg. Paul J. Spangler (17 NMNH ) . Differential Diagnosis. Among Central American species, recognized by the combination of moderate size (ca. 3.60 mm ), the moderately densely punctate pronotum, and the male genitalia ( Fig. 20 ; described below). This species has a generalized Hydrochus habitus ( Fig. 20 ); reliable determinations will require dissection of males. Male genitalia ( Fig. 20 ). General characters: paramere tips sagittate, plsa moderately prominent, narrower at very tip end in lateral view than in dorsal/ventral views, in dorsal/ventral views with medial margins at apex arcuate toward midline, then arcuate away from midline; aedeagus in dorsal/ventral views lanceolate, moderately wide at agw, at ca. midlength; in lateral view slightly narrower, without emargination where adbl and shaft meet; lateral margins of aedeagus sclerotized; basal piece slightly shorter than parameres, in dorsal/ventral views tapering from distal to proximal, in lateral view dorsal surface arcuate, ventral surfacsse straight, orifice strongly sclerotized. Dorsal surface: pdmm widely separated, overlapping aedeagus; adbl moderately large; adtl subapical. Ventral surface: pvmm approximating lateral margin of aedeagus; avtl not apparent; pseudoparameres cylindrical in cross section, ca. ½ as long as parameres. Remarks. I have examined the holotype , including the male genitalia, of H. bernardi (ZMHB) ( Fig. 20 ).