Exocelina bewaniensis Shaverdo, Menufandu & 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 : 3

Taxon classification Animalia Coleoptera Dytiscidae

1. Exocelina bewaniensis Shaverdo, Menufandu & Balke sp. n. Figs 21-23, 49

Exocelina undescribed sp. MB1295: Toussaint et al. 2014: Supplementary figs 1-4, Tab. 2.

Type locality.

Papua New Guinea: Sandaun Province, Bewani Mts., approximately 03°05.13'S; 141°10.23'E.

Type material.

Holotype: male "Papua New Guinea: Sandaun, Bewani Stn., stream @ base of Bewani Mts., 200-300 m, 12.iv.2006, nr. 03.05.130S 141.10.227E, Balke & Sagata (PNG 37)" (ZSM). Paratypes: Papua New Guinea: 6 males, 5 females with the same label as the holotype, one male additionally with a green label "DNA M.Balke 1295" (NHMW, ZSM). 1 male, 2 females "Papua New Guinea: Sandaun, Bewani Stn., forest puddles @ base of Bewani Mts., 300 m, 12.iv.2006, nr. 03.05.130S 141.10.227E, Balke & Sagata (PNG 38)" (ZSM). Indonesia: Papua Province: Mamberamo Raya Regency: 1 male "IRIAN JAYA: Jayapura Prov. Mamberamo, Rouffaer Mts. Noiadi, 150 - 200m 17.3.1999, leg. Riedel" [approximately 02°46'S, 137°46'E] (NHMW). Sarmi Regency: 13 males, 7 females "Indonesia: Papua, Sarmi Waaf, N Foja Mts, waterfall in forest, 120m, 23.ix.2014, -2.3317793 138.7500472, Menufandu (Pap031)" (MZB, NHMW, ZSM). 6 males, 4 females "Indonesia: Papua, Sarmi area, 70m 25.ix.2014, -1.9713908 138.8491402, Menufandu (Pap032)" (MZB, ZSM). Nabire/Paniai Regencies: 7 males, 3 females "Indonesia: Papua, Road Nabire-Enarotali KM 111, 100m, 23.x.2011, 03 31.192S 135 55.426E, Uncen (PAP15)" (MZB, NHMW, ZSM). 6 males "Indonesia: Papua, Road Nabire-Enarotali KM 80, 250m, 22.x.2011, 03 33.860S 135 46.473E, Uncen (PAP12)" (MZB, NHMW, ZSM).

Diagnosis.

Beetle small, piceous, with paler clypeus and pronotal sides, shiny; pronotum without lateral bead; male antennomeres simple; male protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta; median lobe with weak submedian constriction in ventral view; paramere with distinct notch on dorsal side and subdistal part short, rounded, with upper setae almost inconspicuous or rather distinct and lower relatively long, dense, thick, and flattened. The species is similar to Exocelina soppi Shaverdo, Hendrich & Balke, 2012, from which differs with larger male protarsomere 4, narrower apex of the median lobe, and paramere setae thicker and somewhat flattened.

Description.

Size and shape: Beetle small (TL-H 3.1-3.6 mm, TL 3.45-4.0 mm, MW 1.65-1.95 mm), with oblong-oval habitus, broadest at elytral middle. Coloration: Head brown to piceous, with paler clypeus and sometimes vertex; pronotum with dark brown to piceous disc and reddish brown to dark brown sides; elytra dark brown to piceous, sometimes with narrow reddish brown sutural lines; head appendages yellowish to reddish, legs distally darker, especially metathoracic legs (Fig. 49). Teneral specimens with coloration paler.

Surface sculpture: Head with dense punctation (spaces between punctures 1-3 times size of punctures), evidently finer and sparser anteriorly; diameter of punctures smaller than diameter of cells of microreticulation. Pronotum with much sparser and finer punctation than on head. Elytra with extremely sparse and fine punctation, almost invisible. Pronotum and elytra with weakly impressed microreticulation, dorsal surface shiny. Head with microreticulation stronger. 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 without lateral bead or with weak traces of lateral bead. Base of prosternum and neck of prosternal process with distinct ridge, less rounded anteriorly, with small anterolateral extensions. Blade of prosternal process lanceolate, relatively broad, convex, with distinct lateral bead and few setae; neck and blade of prosternal process evenly jointed. Abdominal ventrite 6 broadly rounded.

Male: Antenna simple (Fig. 21A). Protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of 11-13 and posterior row of 5-6 short setae (Fig. 21B). Abdominal ventrite 6 with 7-14 lateral striae on each side. Median lobe with weak submedian constriction in ventral view and elongate apex in lateral view (Fig. 21C, D). Upper margin of apex distinctly curved or almost straight in lateral view. Paramere with distinct notch on dorsal side and subdistal part short, rounded, with upper setae almost inconspicuous or rather distinct and lower relatively long, dense, thick, and flattened; setae of proximal part more or less numerous, thin (Fig. 21E).

Holotype: TL-H 3.4 mm, TL 3.7 mm, MW 1.8 mm.

Female: Without evident differences in external morphology from males, except for abdominal ventrite 6 without striae.

Variability

(Figs 21-23). Exocelina bewaniensis sp. n. is described using the material from three different regions (Fig. 53). The specimens from these regions demonstrate variability in size (from Bewani: TL-H 3.35-3.45 mm, TL 3.7-3.75 mm, MW 1.75-1.8 mm; Nabire-Enarotali: TL-H 3.1-3.4 mm, TL 3.45-3.85 mm, MW 1.65-1.85 mm; Noiadi: TL-H 3.6 mm, TL 4 mm, MW 1.95 mm), dorsal punctation (in specimens from Nabire-Enarotali, it is slightly coarser), shape of the median lobe (in the specimen from Noiadi, the median lobe with weaker submedian constriction in ventral view and upper margin of apex more straight in lateral view (Figs 21D, 22D, 23D), and setation of the paramere (in specimens from Bewani and Papua, subdistal and proximal setae more numerous, with upper subdistal setae very distinct (Figs 21E, 22E, 23E).

At first, we intended to describe the species with three subspecies as these morphological differences are evident and stable within each region, though insignificant. Finally, we have decided against this, bearing in mind that more material is needed from these regions (especially, from Noiadi) and the regions in-between for a conclusion whether they belong to the different subspecies or maybe even species.

Distribution.

Papua New Guinea: Sandaun Province; Indonesia: Papua Province: Sarmi, Mamberamo Raya and Nabire/Paniai Regencies (Fig. 53).

Etymology.

The name refers to Bewani Mts. where this species was discovered for the first time. The name is an adjective in the nominative singular.