Hydrochus obscurus Sharp, 1882

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 : 48

Hydrochus obscurus Sharp

Figs. 4 , 63

Hydrochus obscurus Sharp 1882: 90

Hydrochus vanbergehenegouweni Makhan 1992 ; syn. Oliva (1996); Perkins (2019c).

Originally described from Guatemala. Records from several South American countries are in the literature; however, some of these records are invalid synonymies proposed by Oliva (1992), for H. corruscans Bruch ( Argentina) (see Perkins 2019a), and H. elsjeae Makhan (which see, herein). Locality data and deposition records have been published for Venezuela and Peru ( Perkins 2019c, 2020c, respectively), and there are many records for Central America ( Perkins, 2021). The locality data records for Bolivia, Brazil and Paraguay are given below. H. obscurus is the most commonly collected Neotropical Hydrochus , has the greatest distribution range ( Paraguay to Mexico, Fig. 63 ), but has not been collected in the high Andes. Habitus and male genitalia illustrations are given in Perkins (2019c, 2020a).

Material examined (106): Bolivia: Beni, 7 km SW Trinidad , elev. 163 m (14°52’12’’S, 64°57’32’’W), 18.vii.1998, leg. K. B. Miller (3 SEMC) ; Beni Stn., Palm Camp, NE. of San Borja, 6–9.viii.1988, leg. Robert W. Brooks (1 SEMC) ; Santa Cruz, 2.7 m S of San Jose , elev. 333 m (17°52’20’’S, 60°44’28’’W), 27.vi.1999, leg. K. B. Miller (5 SEMC) ; Potrerillos del Guenda, Preserva Natural , elev. 370 m (17°40’S, 63°27’W), 1–4.x.2007, leg. Wappes & Morris (2 SEMC) ; Prov. Sara , 2 km NW of Santa Rosa, 21.ii.1969, leg. A. Martinez & R.E. Woodruff (2 NMNH) . Brazil: Amazonas , 20 km SW Itapiranga, 9.xi.1969, leg. JM & BA Campbell (1 NMNH) ; Goias, Santa Isabel, Ilha do Bananal, Rio Araguaia , 15–22.vii.1957, leg. B. Malkin (1 CAS) ; Mato Grosso, Caceres , MT., (16°4’S, 57°41’W), 1–30.xii.1955, leg. M. Alvarenga (6 NMNH) ; same locality, 2–4.xii.1955, leg. M. Alvarenga (9 CAS) ; Corumba -., leg. F. Plaumann [no date] (2 NMNH, 4 NHM); same locality, 21–23.ii.1954, leg. Gans & Pereira (1 NMNH) ; Jacaré, Parque Nacional do Xingu , (15°16’S, 57°42’W), 1–30.xi.1965, leg. M. Alvarenga & Bokermann (1 NMNH) ; Para, Curua R., W. of Santarem, SPVEA—FAO ExpSta , 1.v.1963, leg. F. G. Werner (3 NMNH) ; Rio Xingu Camp, Altamira (ca. 60km S.), (3°39’S, 52°22’W), 1–7.x.1986, leg. P. Spangler & O. Flint (3 NMNH) ;); Rio de Janeiro, Atafona , 1–29.iii.1964, leg. N. Menezes (1 NMNH) . Amazonas , 20 km SW Itapiranga, 9.xi.1969, leg. JM & BA Campbell (1 NMNH) ; Goias, Santa Isabel, Ilha do Bananal, Rio Araguaia , 15–22.vii.1957, leg. B. Malkin (1 CAS) ; Mato Grosso, Caceres , MT., (16°4’S, 57°41’W), 1–30.xii.1955, leg. M. Alvarenga (6 NMNH) ; same locality, 2–4.xii.1955, leg. M. Alvarenga (9 CAS) ; Corumba -., leg. F. Plaumann [no date] (2 NMNH, 4 NHM); same locality, 21–23.ii.1954, leg. Gans & Pereira (1 NMNH) ; Jacaré, Parque Nacional do Xingu , (15°16’S, 57°42’W), 1–30.xi.1965, leg. M. Alvarenga & Bokermann (1 NMNH) ; Mato Grosso do Sul, Corumbá , (c. 29 km SE) on BR-262 -19.3062 -57.60382, 25.vi.2018, Drying marsh with abundant vegetation and detritus, leg. Hamada and team, BR18-0625-02A (1 INPA) ; Mato Grosso do Sul, Corumbá, Paraguay River (-18.95184 -57.66642), 101m, 25.vi.2018, Macrophytes along river margins and in floating island mats, leg. Hamada and team, BR18-0625-01A (1 INPA) ; Brazil , Mato Grosso do Sul, Miranda (c. 9.5 km SW) on MS-339 (-20.32119 -56.42563), 131 m, 26.vi.2018, Marsh area along side stream, leg. Hamada and team, BR18-0626-03A (6 INPA, SEMC) ; Para, Curua R., W. of Santarem, SPVEA—FAO ExpSta , 1.v.1963, leg. F. G. Werner (3 NMNH) ; Rio Xingu Camp, Altamira (ca. 60km S.), (3°39’S, 52°22’W), 1–7.x.1986, leg. P. Spangler & O. Flint (3 NMNH) ; Rio de Janeiro, Atafona , 1–29.iii.1964, leg. N. Menezes (1 NMNH) ; Roraima, Amajari , c. 16 km W on RR-203, (3 36.874’N, 61 33.470’W), 125m, 13.i.2018, marsh, leg. Short, Benetti, Santana, BR 18-0113-04A (1 INPA) ; Amajari, Uraricoera River at BR-174, (3 27.995’N, 60 54.660’W), 85m, 13.i.2018, large pond, leg. Short, Benetti, Santana, BR 18-0113-03A (9 INPA, SEMC) ; Bonfim, Arraia River, nr. BR-401, c. 8 km SW. Bonfim , (3 21.061’N, 59 54.230’W), 80m, 12.i.2018, Gravel margins of river, leg. Short, BR 18-0112-01A -. (2 SEMC) ; Bonfim , BR-401, c. 13 km SW of Bonfim, (3 19.109’N, 59 56.326’W), 100m, 12.i.2018, marsh area with complex of habitats from deep pools to shallow vegetated margins, leg. Short, BR 18-0112-04A (5 SEMC) ; Caroebe, Reservoir by Usina de Jatapú , (0.872953° -59.282170°), 185m, 17.i.2018, small pool on side of stream, leg. Short, BR 18-0117-01C (1 INPA) ; Caroebe, Rio Caroebe , ca. 13 km NE of Caroebe, (00 54.786’N, 59 34.397’W), 150m, 17.i.2018, margins of sandy river, leg. Short & Benetti, BR 18-0117-04A -. (9 INPA, SEMC) ; Caroebe, Rio Jatapú, near Usina de Jatapú , (00 50.939’N, 59 18.262’W), 145m, 17.i.2018, marginal pools of river, leg. Short, BR 18-0117-02A (13 INPA, SEMC) . Paraguay: Dep. Boqueron, Mistolar , (23°13’S, 61°41’W), 3–12.x.1997, leg. Drechsel (12 NMW) ; Dep. Central , Asuncion, 2.x.1992, leg. U. Drechsel (1 NMW) .

Figures

FIGURE 4. Dorsal habitus of Hydrochus species in study area.

FIGURE 63. Geographical distribution of H. obscurus.