Exocelina tabubilensis Shaverdo & Balke

Shaverdo, Helena, Sagata, Katayo, Panjaitan, Rawati, Menufandu, Herlina & Balke, Michael, 2014, Description of 23 new species of the Exocelinaekari-group from New Guinea, with a key to all representatives of the species group (Coleoptera, Dytiscidae, Copelatinae), ZooKeys 468, pp. 1-83 : 29-30

Taxon classification Animalia Coleoptera Dytiscidae

20. Exocelina tabubilensis Shaverdo & Balke sp. n. Figs 6, 34

Type locality.

Papua New Guinea: Western Province, Tabubil, 05°15.67'S; 141°13.74'E.

Type material.

Holotype: male "Papua New Guinea: Western Province, Tabubil, 600m, 22.vi.2008, 05.15.673S 141.13.738E, Posman (PNG 181)" (ZSM). Paratype: 1 male "Papua New Guinea: Sandaun, Mianmin (river) 700m, 21.x.2008, 04.52.858S 141.31.706E Ibalim (PNG 197)" (ZSM).

Diagnosis.

Beetle medium-sized, piceous with paler head and pronotum, submatt; pronotum with distinct lateral bead; male protarsomere 4 with large, slender, evidently curved anterolateral hook-like seta. The species is similar to Exocelina munaso (Shaverdo, Sagata & Balke, 2005) because of shape of the median lobe (with large lateral folds in ventral view) and paramere (without notch on dorsal side). However, it differs from Exocelina munaso with smaller size, evidently narrower blade of prosternal process, male antennomeres 5-7 evidently enlarged, antennomeres 4, 8, 9 slightly enlarged, medial lobe much narrower, submedian constriction evident in ventral view, apex of median lobe almost rounded and not curved downwards in lateral view, and setae of paramere more numerous.

Description.

Size and shape: Beetle medium-sized (TL-H 4.15-4.2 mm, TL 4.55-4.65 mm, MW 2.3-2.35 mm), with oblong-oval habitus, broadest at elytral middle. Coloration: Head dark brown, reddish brown anteriorly and with two reddish brown spots on vertex; pronotum dark brown on disc and gradually paler to yellowish red lateral sides; elytra uniformly piceous; head appendages yellowish-red, legs reddish (Fig. 34).

Surface sculpture: Head with dense punctation (some punctures conjoint or spaces between most of them 1-3 times size of punctures), evidently finer and sparser anteriorly and posteriorly; diameter of punctures equal to diameter of cells of microreticulation. Pronotum with finer, slightly sparser, and more evenly distributed punctation than on head. Elytra with punctuation slightly coarser and denser than on pronotum. Head, pronotum and elytra with strong microreticulation and punctation, dorsal surface submatt. Metaventrite and metacoxa distinctly microreticulate, metacoxal figs with longitudinal strioles and transverse wrinkles. Abdominal ventrites with distinct microreticulation, strioles, and fine sparse punctation, coarser and denser on two last abdominal ventrites.

Structures: Pronotum with distinct lateral bead. Base of prosternum and neck of prosternal process and neck of prosternal process with distinct ridge, smooth and rounded anteriorly, without anterolateral extensions. Blade of prosternal process lanceolate, very narrow, convex, with distinct lateral bead and few setae, apex of blade slightly but distinctly bent upwards; neck and blade of prosternal process evenly jointed. Abdominal ventrite 6 slightly truncate apically.

Male: Antennomeres 5-7 evidently enlarged, antennomeres 4, 8, 9 slightly enlarged (Fig. 6A). Protarsomere 4 with large, slender, evidently curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of more than 40 and posterior row of 16 relatively long setae (Fig. 6B). Abdominal ventrite 6 with 15-17 lateral striae on each side. Median lobe narrow, with very strong submedian constriction and large lateral folds in ventral view and its apex almost rounded and not curved downwards in lateral view (Fig. 6C, D). Paramere without notch on dorsal side, with subdistal setae numerous (Fig. 6E).

Holotype: TL-H 4.15 mm, TL 4.65 mm, MW 2.35 mm.

Female: Unknown.

Distribution.

Papua New Guinea: Western and Sandaun Province. This species is known only from two localities (Fig. 53).

Etymology.

The species is named after the type locality: Tabubil. The name is an adjective in the nominative singular.