Exocelina arfakensis

Size and shape: Beetle middle-sized (TL-H 3.7–4.1 mm, TL 4.1–4.5 mm, MW 2.05–2.2 mm), with oblong-oval habitus, broadest at elytral middle. Coloration: Dorsally piceous, with dark brown pronotal sides; head appendages yellow to red, legs darker (Fig. 36). Surface sculpture: Head with very dense, coarse punctation (spaces between punctures 1–2 times size of punctures), especially on vertex. Pronotum and elytra with punctation much finer and sparser. Pronotum and elytra with somewhat stronger impressed microreticulation, but dorsal surface still shiny. Head with microreticulation stronger. Metaventrite and metacoxa distinctly microreticulate, metacoxal plates with longitudinal strioles and transverse wrinkles. Abdominal sternites with distinct microreticulation, strioles, and fine sparse punctation, coarser and denser on two last abdominal sternites. Structures: Pronotum with distinct lateral bead. Base of prosternum and neck of prosternal process with distinct ridge, rounded and smooth anteriorly, with small anterolateral extensions. Blade of prosternal process lanceolate, relatively broad, convex, with distinct bead and few setae; neck and blade of prosternal process evenly jointed. Abdominal sternite 7 broadly rounded apically. Male: Antennomeres 3–4 strongly enlarged and triangular (3 larger than 4), 5–6 distinctly enlarged, 7 somewhat enlarged (Fig. 10A); antennomeres 3–7 rugose ventrally. Protarsomere 4 with small, thick (evidently thicker and slightly longer than more laterally situated large seta), slightly curved anterolateral hook. Protarsomere 5 ventrally with anterior row of 11 short setae and posterior row 5 short setae (Fig. 10B). Abdominal sternite 7 with 6–8 lateral striae on each side. Median lobe with strong submedian constriction in ventral view, apex of median lobe elongate in lateral view and narrower in ventral view (Figs 10C, D). Paramere with notch on dorsal side and subdistal part short and small, with not numerous, relatively short, thick, and flattened setae (Fig. 10E). Female: Dorsal punctation slightly coarser, antennae simple, sternite 7 without striae.

Indonesia: West Papua Province: Manokwari Regency. The species is known only from the Arfak Mountains, the eastern part of Bird’s head (Fig. 50).