Hydrochus brianbrowni Makhan
Creators: name: Perkins, Philip D.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Hydrochidae
Hydrochus
Hydrochus brianbrowni

description: Hydrochus brianbrowni Makhan
Figs. 2, 9, 31
Hydrochus brianbrowni Makhan 2005: 63.
Originally described from southern Arizona. New locality data records for Mexico are given below
Material examined (52): Mexico: Baja California, Arroyo Saltito nr. Las Cruces, E. of La Paz, 23.i.1959, leg. H. B. Leech (1 CAS); Baja California Sur, 9 mi. up Canyon San Bernardo fr. Boca de la Sierra (Potrero), elev. 457 m (23°23’N, 109°57’W), 2.viii.1971, leg. H. G. Real & R. E. Main (1 FSCA, 37 CAS); Sa. Victoria, 7 mi. W Santiago, (23°28’N, 109°50’W), 30-31.x.1968, leg. E. L. Sleeper & F. J. Moore (1 CAS); Jalisco, Mpio. Tomatlán, Cajón de Peñas, 120 m, 15.vi.1994, G. Nogueira col. (1 IEXA); Quintana Roo, Pto. Morelos, 29.iv.1982, leg. O. Comul (1 UNAM); San Luis Potosi, 2 mi. S. San Luis Potosi, 21.xi.1948, leg. H. B. Leech (1 CAS); Sinaloa, Los Mochis, 8.vii.1922, leg. C.T. Dodds (1 CAS); Sonora, 20 mi. W. Moctezuma, 28.ix.1980, leg. no collector on label (2 NMNH); 7 mi. SE Alamos, 27.xi.1971, leg. K. Stephan (2 NMNH); La Pintada, 6.xi.1986, leg. F. Arias (3 UNAM); Zacatecas, Teul de Gonzalez Ortega, Huitzila; borde arroyo, elev. 1718 m (21°36’46.1’’N, 103°36’22.2’’W), 31.i.2004, leg. V.Gomez & J.L. Navarrete-Heredia (1 NMNH).
Differential diagnosis. Among Central American species, recognized by the combination of moderate size (ca. 2.94 mm), the deep pronotal depressions, and the male genitalia (Fig. 9; described below). This species has a generalized Hydrochus habitus; reliable determinations will require dissection of males. The aedeagus is very narrow, for comparison refer to the diagnosis of H. nayaritensis n. sp.
Male genitalia (Fig. 9). General characters: paramere tips slender and pointed, narrower 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, slightly narrowed proximal to plsa; aedeagus in dorsal/ventral views very slender, parallel-sided or nearly so for entire length, apex pointed; in lateral view wider at base and slightly wider for remainder of length; lateral margins of aedeagus sclerotized; basal piece in dorsal/ventral views tapering from distal to proximal, in lateral view slightly wider proximally than distally, shorter than parameres, orifice strongly sclerotized.
Dorsal surface: pdmm widely separated, overlapping aedeagus only very slightly at base; adbl moderately large; adtl at about distal 1/6; each paramere with prominent pwsa; paramere tips without sclerotized ridge.
Ventral surface: pvmm well separated, except narrowly separated where overlapping aedeagus basally; avtl not apparent.
Remarks. I have examined the holotype, including the male genitalia (LANHM). The specimen imaged (Fig. 9) was collected at this locality: Baja California Sur, 9 mi. up Canyon San Bernardo fr. Boca de la Sierra (Potrero).
description: Published as part of Perkins, Philip D., 2021, Taxonomy of Central American water beetles in the genus Hydrochus Leach, 1817 (Coleoptera: Hydrochidae), pp. 459-503 in Zootaxa 4974 (3) on pages 473-474, DOI: 10.11646/zootaxa.4974.3.2, http://zenodo.org/record/4777839