Exocelina wigodukensis, Shaverdo, Helena, Wild, Michael, Sumoked, Bob & Balke, Michael, 2017

Shaverdo, Helena, Wild, Michael, Sumoked, Bob & Balke, Michael, 2017, Six new species of the genus Exocelina Broun, 1886 from Wano Land, New Guinea (Coleoptera, Dytiscidae, Copelatinae), ZooKeys 665, pp. 93-120 : 99-103

8. Exocelina wigodukensis sp. n. Figs 9, 17

Type locality.

Papua: Puncak Jaya Regency, Wigoduk, 03°38'14.52"S; 137°46'57.78"E.

Type

material.

Holotype: male "Indonesia: Papua, Wigoduk, 1800m, 29.xi.2014, S3°38'14.52", E137°46'57.78", M. Wild (W19)" (MZB). Paratypes: 6 males, 3 females with the same label as the holotype, two males with the additional labels "M.Balke 6528" [green text] and "M.Balke 6529" [green text] (NHMW, ZSM). 4 males "Indonesia: Papua, Mokndoma, 2150m, 5.ix.2014, S3°38'38.94", E137°46'30", M. Wild" (NHMW, ZSM).

Additional material.

3 males, 10 females "Indonesia: Papua, Mokndoma, 2150m, 5.ix.2014, S 3° 38' 38.94" E 137° 46' 30", M. Wild", one female additionally with label "M.Balke 6530" [green text] (ZSM).

Diagnosis.

Beetle medium-sized, piceous, with pronotum paler anteriorly and laterally, dorsal punctation dense and coarse, microreticulation strongly impressed; pronotum without lateral bead; male antennae evidently modified: antennomeres 3-4 and 9-10 stout, antennomeres 5-8 distinctly enlarged, larger than other antennomeres; protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta; protarsomere 5 slightly concave ventrally; median lobe slightly curved, narrow, with apex slightly curved downwards as very small “beak” in lateral view; with slightly concave apex and subparallel sides in ventral view; paramere without dorsal notch, subdistal setae numerous, long, dense, strong, proximal setae thin and sparse, inconspicuous.

The species is similar to E. pulukensis sp. n. but distinctly differs from it in having more strongly modified male antennae, thinner and stronger curved apex of the median lobe in lateral view, and three isolated setae of the paramere with very small basal prolongations. Also see under E. pulukensis sp. n.

Description.

Size and shape: Beetle medium-sized (TL-H 3.7-4.35 mm, TL 4.05-4.7 mm, MW 1.95-2.3 mm), with oblong-oval habitus, broadest at elytral middle. Coloration: Head piceous, with narrow reddish brown anterior margin. Pronotum piceous on disc and posterior part and reddish brown anteriorly and laterally. Elytra uniformly piceous. Head appendages reddish brown to dark brown. Legs yellowish red proximally and reddish brown distally (Fig. 9). Ventrum piceous, paler on abdominal ventrites; prosternum, epipleurae, abdominal ventrite 1, and apical part of abdominal ventrite 6 reddish brown. Coloration of teneral specimens paler.

Surface sculpture: Head with dense punctation (spaces between punctures 1-2 times size of punctures), evidently finer and sparser anteriorly; diameter of punctures almost equal to diameter of cells of microreticulation. Pronotum with sparser and finer punctation than head. Elytra with coarse and dense punctation, coarser than on pronotum. Pronotum and elytra with strongly impressed microreticulation, dorsal surface matt. Head with microreticulation stronger. Metaventrite and metacoxae distinctly microreticulate and punctate, metacoxal plates with longitudinal strioles and transverse wrinkles. Abdominal ventrites with distinct microreticulation, strioles, and distinct sparse punctation.

Structures: Pronotum without lateral bead. Base of prosternum and neck of prosternal process with distinct ridge, slightly rounded anteriorly, with small transverse wrinkles. Blade of prosternal process lanceolate, relatively broad, with distinct lateral bead, with small transverse wrinkles on both sides along lateral bead and convex and smooth middle; neck and blade of prosternal process evenly jointed. Abdominal ventrite 6 broadly rounded or slightly truncate apically.

Male: Antenna modified (Fig. 9); antennomeres 3-4 and 9-10 stout, antennomeres 5-8 distinctly enlarged, larger than other antennomeres. Pro- and mesotarsomeres 1-3 slightly dilated. Protarsomere 4 not modified, with large, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 slightly concave ventrally, with anterior band of more than 30 and posterior row of 7 relatively long, not pointed setae (Fig. 17D). Median lobe slightly curved, narrow, with apex slightly curved downwards as very small “beak” in lateral view; with slightly concave apex and subparallel sides in ventral view. Paramere without dorsal notch, subdistal setae numerous, long, dense (forming “brash”), strong, the three most proximal of them standing isolated and slightly modified having small basal prolongations; proximal setae thin and sparse, inconspicuous (Fig. 17 A–C). Abdominal ventrite 6 with 8-12 lateral strioles on each side.

Holotype: TL-H 4.45 mm, TL 4.15 mm, MW 2.2 mm.

Female: Antennomeres stout but thinner than in male. Pro- and mesotarsi not modified. Abdominal ventrite 6 without lateral strioles.

Variability.

There are three specimens (see "Additional material") of much smaller size (TL-H 3.8-3.95 mm, TL 3.2-3.6 mm, MW 1.85-1.9 mm; for E. wigodukensis sp. n. from Mokndoma: TL-H 4.05-4.35 mm, TL 4.3-4.7 mm, MW 2.1-2.3 mm) and with slightly different shape of the median lobe (less curved downwards apex) among the beetles of the population from Mokndoma. More material from the region is necessary to conclude whether two distinct but very similar species occur here or it is just a matter of variability.

Distribution and habitat.

Papua: Puncak Jaya Regency. The species is known from two localities: Wigoduk and Mokndoma (Fig. 19).

At 2150 m, Mokndoma is an area of high cloud forest. Although this area lies within the territory of the Wano tribe, the word Mokndoma is from the neighboring Dem language. Mok means “flat” and Ndoma means “ground”. So the name of the place is literally "Flat ground". This is the current home of the second author. In many places at Mokndoma, the ground is boggy with lots of moss and tannin stained streams and ponds. It is an almost mystical place featuring moss tunnels, bog grass, mountain rhododendrons, woody epiphytes, wild ginger and many shrubby small coniferous trees. Upon leaving the open flat area and heading into the thick jungle to the east, west or south, one finds many small streams (Fig. 1) and puddles in which Exocelina beetles abound.

Wigoduk is the name of a valley system to the northeast of Mokndoma. It is about onehour hike from the second author’s house site in Mokndoma. Wigoduk is located at 1800 m, right on the eastern bank of a wide bend in the Nggoduk River (Fig. 2). The Nggoduk River is approximately 6-8 m wide and most times only knee deep. In the Wigoduk valley, it meanders along, but upon exiting the valley, turns turbulent as it hurries down the mountain to the larger Yamo River at the bottom of a large east to west running valley at about 1000 m elevation. The Nggoduk River banks are made of smooth rocks and pebbles, a superb site for collecting many different Co leoptera . Exocelina beetles are found around this area and on the trail from Mokndoma to Wigoduk in many very small streams and puddles.

Etymology.

The name refers to Wigoduk, the type locality. The name is an adjective in the nominative singular.