Exocelina simbaijimi 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 : 38-40

22. Exocelina simbaijimi Shaverdo & Balke sp. n. Figs 17, 41

Exocelina undescribed sp. MB3312: Toussaint et al. 2014: supplementary figs 1-4, table 2; Toussaint et al. 2015: supplementary figs S1-S2, table S3.

Exocelina simbaijimi _New_Guinea_MB3312: Toussaint et al. 2015: supplementary information S5-S6.

Type locality.

Papua New Guinea: Western Highlands Province, Simbai-Jimi, 05°16.07'S, 144°27.89'E, 1,500 m a.s.l.

Type material.

Holotype: male "Papua New Guinea: Western Highlands, Simbai - Jimi, 1500m, 2.iii.2007, 05.16.074S 144.27.886E, Kinibel (PNG 140)" (ZSM). Paratypes: 6 males with the same label as the holotype (NHMW, ZSM). 2 males, 3 females "Papua New Guinea: Western Highlands, Simbai, Kairong River, 1850m, 2.iii.2007, 05.14.840S 144.28.457E, Kinibel (PNG 139)", one male with an additional green label "M.Balke 3310" (NHMW, ZSM). 3 males, 1 female "Papua New Guinea: Western Highlands, Jimi, 1500m, 2.iii.2007, 05.16.335S 144.27.930E, Kinibel (PNG 141)" (ZSM). 7 males, 1 female "Papua New Guinea: Western Highlands, Gonzsidai-Sarup, 1700m, 4.iii.2007, 05.19.060S 144.28.671E, Kinibel (PNG 144)", one male with an additional green label "M.Balke 3312" (NHMW, ZSM). 2 males, 1 female "Papua New Guinea: Western Highlands, Kundum, 1400m, 03.III.2007, 05.16.096S 144.27.869E, Kinibel (PNG 142)" (NHMW, ZSM).

Additional material.

1 female "Papua New Guinea: Western Highlands, Simbai, 1800-2000m, 25.ii.2007, 05.16.330S 144.33.176E, Kinibel (PNG 133)" (ZSM). 1 female "Papua New Guinea: Western Highlands, Simbai, 1800-2000m, 1.iii.2007, 05.14.2760S 144.28.741E, Kinibel (PNG 138)" (ZSM).

Description.

Body size and form: Beetle medium-sized: TL-H 4.05-5.0 mm, TL 4.4-5.4 mm, MW 2.1-2.55 mm (holotype: TL-H 5.0 mm, TL 5.4 mm, MW 2.5 mm), with oblong-oval habitus.

Coloration: Piceous, with head and pronotum paler. Head dark brown to piceous, reddish brown to brown anteriorly, with small darker areas posterior to eyes. Pronotum reddish brown to brown laterally and piceous on disc. Elytra brown to piceous, sometimes with narrow reddish sutural lines. Head appendages and legs proximally reddish, legs distally darker, brown, especially metathoracic legs (Fig. 17). Teneral specimens paler.

Surface sculpture: Submatt dorsally. Head with rather dense, coarse punctation (spaces between punctures 1-2 times size of punctures), evidently finer and sparser anteriorly; diameter of punctures smaller than or equal to diameter of cells of microreticulation. Pronotum with distinct punctation, sparser and finer than on head. Elytra with very fine and sparse punctation. Pronotum and elytra with 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, strioles, and fine, sparse punctation.

Structures: Pronotum with distinct lateral bead. Its lateral sides with 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 or broadly rounded.

Male: Antennae simple (Fig. 17). Protarsomere 4 with anterior angle slightly expanded, with large, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 long and narrow, slightly concave ventrally, with anterior band of more than 80 and posterior band of ca 30 relatively long setae (Fig. 41D). Median lobe in lateral view evenly broad, with rounded, slightly angulated, thickened apex; in ventral view, almost subparallel, with broadly rounded apex, with thickened margins. Paramere slightly concave on dorsal side and with long, dense, thin setae situated along dorsal margin: subdistal setae denser, proximal setae sparser, setae in middle finer (Fig. 41 A–C). Abdominal ventrite 6 with 9-14 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 simbaijimi sp. n. is similar to E. heidiae in body size and form but differs from it in darker coloration, more distinct dorsal punctation, broader median lobe, with more angulated apex in lateral view and more thickened margins in ventral view.

Distribution.

Papua New Guinea: Western Highlands Province (Fig. 50).

Etymology.

The species is named after Simbai-Jimi area. The name is a noun in the nominative singular standing in apposition.