Hydrochus bituberculatus Perkins

Perkins, Philip D., 2021, Taxonomy of water beetles in the genus Hydrochus Leach, 1817, from Bolivia, Brazil and Paraguay (Coleoptera: Hydrochidae), Zootaxa 4994 (1), pp. 1-93 : 41-42

Hydrochus bituberculatus Perkins

Fig. 5

Hydrochus bituberculatus Perkins 2019: 11

Originally described from Venezuela; additional locality records have been published for Ecuador and Peru ( Perkins, 2020b, c). Habitus and male genitalia images are given in Perkins (2019c). The following new locality and deposition records are from Bolivia, Brazil, and Paraguay.

Material examined (62): Bolivia: Beni, 7 km SW Trinidad , elev. 163 m (14°52’12’’S, 64°57’32’’W), 18.vii.1998, leg. K. B. Miller (1 SEMC) ; Beni Stn., Palm Camp, NE. of San Borja , 6–9.viii.1988, leg. Robert W. Brooks (1 SEMC) ; Santa Cruz, 60 mi. N. Santa Cruz, Saavedra Exp. Sta. , 27–30.xii.1959, leg. Robert Cumming (22 NMNH) ; Ayacucho , 13–14.v.1969, leg. P. & P. Spangler (12 NMNH) ; Okinawa , 6.vi.1958, leg. E. Pinckert (6 NMNH) ; Potrerillos del Guenda, Preserva Natural , elev. 370 m (17°40’S, 63°27’W), 17–22.x.2007, leg. J. & F. Romero (1 SEMC) ; Santa Cruz, 11–12.v.1969, leg. P. & P. Spangler (7 NMNH) . Brazil: Goias, Santa Isabel, Ilha do Bananal, Rio Araguaia , 12–22.viii.1957, leg. B. Malkin (1 NMNH) ; Mato Grosso, Corumba , (17°32’S, 56°27’W), 21–23.ii.1954, leg. Gans & Pereira (5 NMNH) ; Mato Grosso side of Rio Araguaia, Santa Isabel , (17°12’S, 57°0’W), 12–22.viii.1957, leg. Borys Malkin (2 NMNH) ; Mato Grosso do Sul, Corumbá, Corumba, Paraguay River -18.95184 -57.66642, 101m, 25.vi.2018, Macrophytes along river margins and in floating island mats, Hamada and team, BR18-0625-01A (2 INPA, SEMC) . Paraguay: Dep. San Pedro, Puerto Antequera , 540 ft., black lights, 24.vi.2006, leg. W.D. Shepard (WDS-T-193) (2 SEMC) .

Remarks. Specimens from Brazil are usually smaller than the holotype, which is from Venezuela. The male genitalia of Brazilian specimens are smaller, narrower (for example, basal piece length/width ratio ca. 2.3 for Brazil, and 1.8 for Venezuela) and have the paramere tips shaped slightly differently than the holotype (the lateral margin of the tips between the plsa and the apex are very slightly arcuate in the holotype, and very slightly emarginate in Brazilian specimens). However, specimens from Bolivia and Peru are intermediate in these characters.

Figures

FIGURE 5. Dorsal habitus of Hydrochus species in study area.