Dineutus

Polhemus, Dan A., 2011, New distributional records for Gyrinidae (Insecta: Coleoptera) on New Guinea and nearby islands, with a checklist of the New Guinea species, Zootaxa 2900, pp. 51-68 : 62

Dineutus (Subgenus Merodineutus ) Ochs, 1955

Discussion. Members of this subgenus are very large, ovate to rotund gyrinids found at higher elevations in the central mountain ranges of New Guinea. They typically occur on shaded pools along rocky upland streams, in habitats similar to those preferred by species in the subgenus Rhombodineutus , with which they are occasionally syntopic.

Dineutus (Merodineutus) archboldianus Ochs, 1955 Fig. 6

Dineutus (Merodineutus) archboldianus Ochs, 1955: 150 .

Material examined. INDONESIA, Papua Prov. [= former Irian Jaya Prov.]: 1 male, 1 female, Wapoga River basin, upper Ziwa River at PTFI Wapoga Alpha drilling camp, 1050 m. [3500 ft.], 3°08'41"S, 136°34'25"E, water temp. 19° C., 19 April 1998, 08:00–12:00 hrs., CL 7101, D. A. Polhemus ( USNM); 1 male, Wapoga River basin, rocky rainforest tributary to upper Ziwa River at PTFI Wapoga Alpha drilling camp, 1050 m. [3500 ft.], 3°08'41"S, 136°34'25"E, water temp. 20° C., 18 April 1998, 10:00–17:00 hrs.; 19 April 1998, 14:00–18:00 hrs., CL 7100, D. A. Polhemus ( USNM).

Discussion. This large species was previously known from the Mamberamo River basin; the new records extend the range of this species into the Wapoga River basin immediately to the west ( Fig. 6 ).

For notes on the Ziwa River locality where this species was taken see the discussion under Dineutus (Rhombodineutus) heurni . In addition to being collected along the main river at this locality, specimens were also collected from a moderately small, clear tributary stream, less than 1 m. deep, with flowing pools, riffles and small cascades partially shaded by tall stature montane rain forest. On this creek, the gyrinids were taken along an open, gravel-bottomed reach bordered by quiet side pools. Based on known collections, this species occupies the West Papuan Central Highlands area of freshwater endemism (Area 20) as defined by Polhemus & Allen (2007).

This is the species listed as “ Merodineutus sp. undet” from sampling stations 56–58 in Polhemus (2000).

Figures

FIGURE 6. Distribution of certain Dineutus (Merodineutus) species on New Guinea. Symbols with grey centers represent previous records; symbols with black centers represent new records presented in this paper.