Dineutus ( Rhombodineutus ) pectoralis biakensis Brinck, 1983

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 biakensis Brinck, 1983

Fig. 2

Dineutus ( Rhombodineutus) pectoralis biakensis Brinck, 1983: 220 .

Material examined. INDONESIA, Papua Prov. [= former Irian Jaya Prov.]: 3 males, 15 females, Biak Is., Faknidi River (trib. to Wari River) at Faknidi, 150 m. [ 500 ft.], 0°53'32"S, 135°59'23"E, water temp. 25.5 °C., 12 January 1997, 14:30–15:30 hrs., CL 7038, D. A. Polhemus ( USNM).

Discussion. This subspecies is apparently endemic to the island of Biak ( Fig. 2 ), and was previously known from a total of 6 specimens, the majority taken by J. L. Gressit at Kampong Landbouw ( Brinck, 1983), a locality not found on maps but noted by Gressitt as being near the center of the island.

More recent collections have come from the Faknidi River, which was a relatively slow flowing stream with a bed of sand, gravel and cobbles, partially shaded by disturbed upland rain forest growing on a limestone plateau. The gyrinids were taken from a large, deep pool formed at a road crossing. Based on known collections, this subspecies occupies the Biak/Supiori area of freshwater endemism (Area 8) 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.