Exocelina mantembu 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 : 15-16

Taxon classification Animalia Coleoptera Dytiscidae

10. Exocelina mantembu Shaverdo & Balke sp. n. Figs 25, 50

Exocelina undescribed sp. MB0060: Toussaint et al. 2014: Supplementary figs 1-4, Tab. 2.

Type locality.

Indonesia: Papua Province: Yapen Islands Regency, Mantembu, near Serui, approximately 01°50'S; 136°14'E.

Type material.

Holotype: male "Irian Java: Japen [sic!] Isl. Mantembu 150-450 m, 18.2.1992 leg. Riedel" (NHMW). Paratypes: 8 males, 4 female with the same label as the holotype (MZB, NHMW, ZSM). 6 males, 6 females "Indonesia: Papua, Japen [sic!] Mantembu A. Riedel" (ZSM). 1 male "59 DNA M Balke" [green], “Mantembu” [hw] (ZSM). 1 male "60 DNA M Balke" [green], “Mantembu” [hw] (ZSM).

Diagnosis.

Beetle small, dark brown, with paler head and pronotum, shiny; pronotum without lateral bead; male antennomeres simple; male protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta; median lobe slender, with very weak submedian constriction in ventral view and broadly rounded, elongate apex in lateral view; paramere with shallow notch on dorsal side and subdistal part elongate but broad, with large brush of long, dense, thick, somewhat flattened setae, distal ones longer and curved at apex; setae of proximal part short, thin, almost invisible. The species is similar to Exocelina lembena sp. n., from which differs with shape of the median lobe apex and shallow notch on dorsal side of the paramere. There are only two species on Yapen Island, which can be easily distinguished with size and dorsal sculpture: Exocelina mantembu sp. n., small and shiny, and Exocelina vladimiri , large and matt, as well as using shape and structure of the male genitalia.

Description.

Size and shape: Beetle small (TL-H 3.15-3.45 mm, TL 3.50-3.85 mm, MW 1.65-1.85 mm), with oblong-oval habitus, broadest at elytral middle, some specimens narrower towards elytral apex. Coloration: Head reddish brown, darker posterior eyes; pronotum reddish brown, with paler sides; elytra uniformly dark brown; head appendages reddish brown, legs darker, especially metathoracic legs (Fig. 50).

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. Base of prosternum and neck of prosternal process with distinct ridge, less rounded anteriorly, without 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 or slightly truncate apically.

Male: Antenna simple (Fig. 25A). Protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of 11 short setae and posterior row of 4 short setae (Fig. 25B). Abdominal ventrite 6 with 8-11 lateral striae on each side. Median lobe slender, with very weak submedian constriction in ventral view and broadly rounded, elongate apex in lateral view (Fig. 25C, D). Paramere with shallow notch on dorsal side and subdistal part elongate but broad, with large brush of long, dense, relatively thick, somewhat flattened setae, distal ones longer and curved at apex; setae of proximal part short, thin, almost invisible (Fig. 25E).

Holotype: TL-H 3.45 mm, TL 3.85 mm, MW 1.85 mm.

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

Distribution.

Indonesia: Papua Province: Yapen Islands Regency. This species is known only from the type locality (Fig. 53).

Etymology.

The name refers to the region Mantembu where this species was collected. The name is a noun in the nominative singular standing in apposition.