Dineutus (Rhombodineutus) silenus 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 : 60-61

Dineutus (Rhombodineutus) silenus Brinck, 1983

Fig. 5

Dineutus (Rhombodineutus) silenus Brinck, 1983: 224 .

Material examined. INDONESIA, Papua Prov. [= former Irian Jaya Prov.]: 4 males, 20 females, rocky stream at PTFI Helipad 60, NE of the head of Etna Bay, 90 m. [300 ft.], 3°56'55"S, 134° 59'02"E, water temp. 24.5° C., 30 March 1997, 08:00–09:45 hrs., CL 7080, D. A. Polhemus ( USNM).

Discussion. This species was previously known only from the original type series of 7 specimens collected at Etna Bay in 1904 ( Brinck, 1983). New collections area at hand from the same drainage basin ( Fig. 5 ), indicating that D. silenus may be locally endemic to Etna Bay and the immediately surrounding region. Based on captures to date, this species occupies the Vogelkop Anticlines area of freshwater endemism (Area 6) as defined by Polhemus & Allen (2007).

The Helipad 60 collecting site consisted of a moderately small, clear stream flowing in a partially shaded bed of cobble and gravel in a small, tight valley amid the steep hills behind Etna Bay. The locality, which was accessed by helicopter, was also a geology field survey camp for P. T. Freeport Indonesia (PTFI) mining company. This is the species listed as “ Rhombodineutus sp. undet.” in Polhemus (1998).

Figures

FIGURE 5. Distribution of certain Dineutus (Rhombodineutus) species and subspecies on New Guinea. Symbols with grey centers represent previous records; symbols with black centers represent new records presented in this paper.