Dineutus (Rhombodineutus) pectoralis pectoralis Régimbart, 1882

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 : 54

Dineutus (Rhombodineutus) pectoralis pectoralis Régimbart, 1882

Fig. 2

Dineutes pectoralis Régimbart, 1882: 70 .

Dineutus (Rhombodineutus) pectoralis: Ochs, 1926: 140 .

Material examined. INDONESIA, Papua Prov. [= former Irian Jaya Prov.]: 8 males, 10 females, Vogelkop Peninsula, Arfak Mountains, small rocky stream at Aimasi Hulu, 65 km. SW of Manokwari, 140 m. [450 ft.], water temp. 25° C., 19 Oct. 1991, CL 2649, [0°53'49"S, 133°47'55"E], D. A. and J. T. Polhemus ( BPBM).

Discussion. This nominate subspecies of D. (R.) pectoralis has been taken only in the northeastern section of the Vogelkop Peninsula of western New Guinea ( Brinck, 1983). In preparing his revision of New Guinea Rhombodineutus, Brinck (1983) was able to study only the single male holotype taken by d’Albertis at Andai in 1872. The new series below thus greatly increases the documented material for this taxon, and extends the range slightly to the west, into interior Vogelkop ( Fig. 2 ). The specimens were taken from a small, clear stream emerging from primary rain forest along the foothills of the Arfak Mountains into an adjacent oil palm plantation. This stream was 0.25–0.50 m. deep, flowing over a bed of igneous rocks and sand through a set of quiet pools alternating with riffles and small cascades.

Based on known collections, this subspecies occupies the Vogelkop Highlands area of freshwater endemism (Area 5) as defined by Polhemus & Allen (2007).

Figures

FIGURE 2. Distribution of certain Dineutus (Rhombodineutus) pectoralis subspecies on New Guinea and adjacent islands. Symbols with grey centers represent previous records; symbols with black centers represent new records presented in this paper.