Exocelina mendiensis Shaverdo & Balke

Shaverdo, Helena, Sagata, Katayo & Balke, Michael, 2018, Introduction of the Exocelinacasuarina-group, with a key to its representatives and descriptions of 19 new species from New Guinea (Coleoptera, Dytiscidae, Copelatinae), ZooKeys 803, pp. 7-70 : 25-27

12. Exocelina mendiensis Shaverdo & Balke sp. n. Figs 24, 48

Exocelina undescribed sp. MB1337: Toussaint et al. 2014: supplementary figs 1-4, table 2; Toussaint et al. 2015: supplementary figs S1-S2, table S3.

Exocelina mendiensis _New_Guinea_MB1337: Toussaint et al. 2015: supplementary information S5-S6.

Type locality.

Papua New Guinea: Southern Highlands Province, Sopulkul, 30-35 km NE Mendi, 06°02.94'S, 143°46.49'E, 2680 m a.s.l.

Type material.

Holotype: male "M. Balke 1337", "Papua New Guinea: Southern Highlands, Sopulkul, 30-35 km NE Mendi, 2680 m, 16.vi.2006, 06.02.944S 143.46.485E, John (PNG 79)" (ZSM). Paratypes: 1 male, 2 females with the same label as the holotype (NHMW, ZSM).

Description.

Body size and form: Beetle large: TL-H 4.8-5.5 mm, TL 5.3-5.9 mm, MW 2.6-2.75 mm (holotype: TL-H 4.8 mm, TL 5.3 mm, MW 2.6 mm), with broader, oblong-oval habitus.

Coloration: Piceous. Head piceous, narrowly brownish anteriorly and sometimes with two brownish spots between eyes. Pronotum piceous, brownish laterally and anteriorly. Elytra piceous, sometime with narrow brownish sutural lines. Head appendages and legs proximally reddish brown, legs distally darker, brownish, especially metathoracic legs (Fig. 24).

Surface sculpture: Submatt dorsally. Head with relatively dense punctation (no spaces between punctures or spaces 2 times size of punctures), sparser anteriorly, denser and coarser between eyes; diameter of punctures smaller than or equal to diameter of cells of microreticulation. Pronotum with relatively dense but fine punctation, sparser and finer than on head. Elytra with very fine, sparse punctation. Pronotum and elytra with rather strongly impressed microreticulation. Head with microreticulation stronger. Metaventrite and metacoxae distinctly microreticulate, metacoxal plates with longitudinal strioles and transverse wrinkles, abdominal ventrites with distinct microreticulation and strioles. Metaventrite medially, metacoxal plates, and abdominal ventrites with very fine, sparse punctation.

Structures: Pronotum with distinct lateral bead. Its lateral sides with distinct longitudinal impressions. Base of prosternum and neck of prosternal process with distinct ridge, slightly rounded anteriorly. Blade of prosternal process lanceolate, relatively narrow, slightly convex, and smooth, with distinct lateral bead and few lateral setae. Abdominal ventrite 6 slightly truncate.

Male: Antennae simple (Fig. 24). Protarsomere 4 with anterior angle slightly expanded, with large, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 with anterior band of more than 60 and posterior row of 16 relatively long setae (Fig. 48D). Median lobe in lateral view long, slightly curved, with small, slightly bent downwards, thickened apex; in ventral view, evenly tapering to broadly pointed apex. Paramere slightly concave on dorsal side and with weak dorsal setation, setae on subdistal part stronger and denser than proximal setae (Fig. 48 A–C). Abdominal ventrite 6 with 23-27 lateral striae on each side.

Female: Without evident differences in external morphology from males, except for not modified protarsi and abdominal ventrite 6 without striae.

Affinities.

Exocelina mendiensis sp. n. is similar to the larger species of the group, E. kumulensis sp. n. and E. ambua sp. n., but differs from them in its darker coloration, shinier dorsal surface and shape of the median lobe. Also, see under E. okapa sp. n.

Distribution.

Papua New Guinea: Southern Highlands Province. The species is known only from the type locality (Fig. 50).

Etymology.

The species is named after Mendi Village. The name is an adjective in the nominative singular.