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 foveatus Haldeman Figs. 2 , 15, 16 , 36 Hydrochus foveatus Haldeman, 1852: 375 ; lectotype designation Worthington et al. 2016 . Hydrochus monishi Makhan, 1995 . Syn. Worthington et al. 2016 . Originally described from Texas; the following are new locality records from Mexico . Material examined (17) : Mexico : Nuevo Leon , 10 km N Linares ; ex. mercury vapor lite, elev. 430 m , 22.iii.1991 , leg. R. Brooks , R. Leschen (3 SEMC ) ; Nuevo Leon , Rio Ramos , 19.vii.1968 , leg. F. N. Young (#2304) (1 NMNH ) ; Rio Ramos near Allende , 18.viii.1954 , leg. F. N. Young (1106) (1 NMNH ) ; Siesta Motel , 6 mi. S. of Monterrey , 28.vi.1966 , leg. R. E. Woodruff (2 NMNH ) ; San Luis Potosi , Ciudad Valles , 22.viii.1964 , leg. Paul J. Spangler (1 NMNH ) ; Clear stream at Palitla , 5 mi. N. of Tamazunchale , 22.xii.1948 , leg. Hugh B. Leech (1 CAS ) ; Huichihuayan , 25.ix.1938 , leg. L. J. Lipovsky (1 SEMC ) ; Tamaulipas , 5 miles sse. of Gomez Farias , 19.vii.1970 , leg. Shaffner , Hart , Murray , Phelps (1 NMNH ) ; Gomez Farias , 3 mi. W. El Encino , 16.iii.1983 , leg. M. S. Davis (2 UMRM ) ; Veracruz , 9 mi. W. Poza Rica , 27.viii.1965 , leg. Paul J. Spangler (4 NMNH ) . Differential diagnosis. Among Central American species, recognized by the combination of moderate size (ca. 3.50–3.56 mm ), the deep pronotal foveae, the large elytral tubercle of the 5 th interstria, and the male genitalia ( Figs. 15, 16 ; described below). This species has a generalized Hydrochus habitus; reliable determinations will require dissection of males. The male genitalia are distinct from other Central American species by virtue of the following combinations of characters: genitalia large, paramere tips sagittate, adtl very near apex of aedeagus, aedeagus wide, pseudoparameres large. Male genitalia ( Figs. 15, 16 ). General characters: paramere tips sagittate, plsa prominent, narrower at very tip end in lateral view than in dorsal/ventral views, in dorsal/ventral views with medial margins at apex parallel or nearly so, then arcuate away from midline; aedeagus in dorsal/ventral views lanceolate, very 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 surface straight, orifice strongly sclerotized. Dorsal surface: pdmm moderately widely separated, slightly sinuate, overlapping aedeagus; adbl very small; adtl subapical. Ventral surface: pvmm approximating lateral margin of aedeagus; avtl at ca. proximal 1/3. Remarks. The one specimen in the LeConte collection at the MCZ, a female, was designated lectotype by Worthington et al. (2016) . Images of the habitus and labels of this specimen are given herein ( Fig. 16 ). The specimen imaged ( Fig. 15 ) has this locality data: Nuevo Leon , Rio Ramos near Allende, 18.viii.1954 , leg. F. N. Young.