Exocelina bifida Shaverdo, Hendrich & Balke

Shaverdo, Helena V., Surbakti, Suriani, Hendrich, Lars & Balke, Michael, 2012, Introduction of the Exocelina ekari-group with descriptions of 22 new species from New Guinea (Coleoptera, Dytiscidae, Copelatinae), ZooKeys 250, pp. 1-76 : 8-9

6. Exocelina bifida Shaverdo, Hendrich & Balke sp. n. Figs 15 A–E, 41

Type locality.

Indonesia: Papua Province: Jayawijaya Regency, Borme, Tarmlu, approximately 04°24'S, 140°25'E.

Type material.

Holotype: male "IRIAN JAYA: Borme Tarmlu 1500m 6.9.1993", "ca. 140°25'E, 04°24'S leg. M. Balke (4-6)" (NHMW). Paratypes: 6 males, 3 females with the same label as the holotype, one of the females additionally with a green label "DNA M.Balke 3256" (NHMW). 3 males "IRIAN JAYA: Borme Tarmlu 1500m 6.9.1993", "ca. 140°25'E, 04°24'S leg. M. Balke (4)" (NHMW).

Diagnosis.

Beetle small, dark brown to piceous, shiny; pronotum without lateral bead; male antennomeres simple; male protarsomere 4 with large, thick, strongly curved anterolateral hook; median lobe with strong submedian constriction and apex bifid: with small dorsal extension; paramere with notch on dorsal side and subdistal part elongate, with dense, long, thin setae. The species is well recognizable by its characteristic male genitalia.

Description.

Size and shape: Beetle small (TL-H 3.5-3.75 mm, TL 3.9-4.25 mm, MW 1.8-2.0 mm), with oblong-oval habitus, broadest at elytral middle. Coloration: Head reddish-brown to piceous, paler anteriorly; pronotum dark brown to piceous, with paler sides, yellowish in anterior angles; elytra dark brown to piceous, with reddish-brown sutural bands; head appendages yellow to yellowish-red, legs distally darker (Fig. 41).

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 finer and sparser punctation than on head. Elytra with very sparse and fine punctation, almost invisible. Head, pronotum, and elytra with weakly impressed microreticulation, dorsal surface, thus, 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 without lateral bead. Base of prosternum and neck of prosternal process with distinct ridge, anteriorly less rounded, smooth, with small anterolateral extensions. Blade of prosternal process lanceolate, relatively broad, slightly convex, with distinct bead and few setae; neck and blade of prosternal process evenly jointed. Abdominal sternite 7 broadly rounded apically.

Male: Antenna simple (Fig. 15A). Protarsomere 4 with large, thick, strongly curved anterolateral hook. Protarsomere 5 ventrally with anterior row of 14 short setae and posterior row of 3 short setae (Fig. 15B). Abdominal sternite 7 with 6-10 lateral striae on each side. Median lobe with strong submedian constriction and apex bifid: with small dorsal extension (Figs 15C, D). Paramere with notch on dorsal side and subdistal part elongate, with dense, long, thin setae (Fig. 15E).

Female: Without evident differences in external morphology from male, except for abdominal sternite 7 without striae.

Distribution.

Indonesia: Papua Province, Jayawijaya Regency. This species is known only from the type locality (Fig. 50).

Etymology.

The name refers to the bifid distalodorsal part of the median lobe. The name is an adjective in the nominative singular.