Papua: Pegunungan Bintang Regency, Ok Bap, 4°49'28.6"S; 140°24'47.0"E, 1961 m a.s.l.

Holotype: male “Indonesia: Papua, nr Ok Bab [sic!], 1961m, 8.vi.2015, -4,82460033148527 140.413050251081, Sumoked (Pap049)” (MZB). Paratypes: Indonesia: Papua: 10 males and 6 females with the same label as the holotype (MZB, NHMW, ZSM). 3 males, 3 females “Indonesia: Papua, nr Ok Bab, 2121 m, 8.vi.2015, -4,84880341216921 140,367602147161, Sumoked (Pap050)”, one male and one female with additional labels with green text “M. Balke 7002” and “M. Balke 7003” (NHMW, ZSM). 3 males, 2 females “Indonesia: Papua, N Ok Sibil, 1564m, 10.vi.2015, -4,87003368 140,64401, Sumoked (Pap052)”, two males with additional labels with green text “M. Balke 7000” and “M. Balke 6999” (NHMW, ZSM). PNG: Sandaun: 1 male “PAPUA, Selminumtem [Selminum Tem, 45 km SWS Telefomin, ca. 5°S; 141°15'E], W.Sepik d. P.Beron leg.”, “Copelatus nomax J.B.Br. det.V. Guéorguiev 1917” [partly hw] (NHMW). 1 male “PAPUA N.G.: Sandaun Prov. Telefomin, 16.-17.5.1998 trail to Eliptamin 1700–1800 m; leg. Riedel” (NHMW).

Beetle medium-sized; usually piceous, with brown pronotal sides; more or less shiny to submatt; pronotum with distinct lateral bead; antennomeres simple or stout; male protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta; male protarsomere 5 long and narrow, without concavity, with anterior row of 18–27 and posterior row of eight relatively short setae; median lobe curved, with apex curved downwards and slightly rounded in lateral view. The species is similar to E. me but its protarsomere 5 is not modified. From E. may sp. n., it differs in a large, strongly curved anterolateral hook-like seta of the male protarsomere 4.

Size and shape: Beetle small to medium-sized (TL-H 3.35–4.5 mm, TL 3.7–4.9 mm, MW 1.75–2.4 mm for Papua populations), with oblong-oval habitus, broadest at elytral middle. Medium-sized specimens more common. Coloration: Head, disc of pronotum and elytra dark brown to piceous, pronotal sides broadly reddish brown, some specimens with narrow reddish sutural lines; head appendages and legs reddish brown, distally darker (Fig. 2). Teneral specimens paler.

Surface sculpture: Head with dense punctation (spaces between punctures 1–2 times size of punctures), finer and sparser anteriorly; diameter of punctures equal to diameter of cells of microreticulation. Pronotum and elytra with distinct punctation, sparser and finer than on head. Elytral punctation slightly sparser than pronotal one. Pronotum and elytra with evident microreticulation, dorsal surface more or less shiny to submatt. Head with microreticulation stronger. Metaventrite and metacoxa distinctly microreticulate, metacoxal plates with longitudinal strioles and transverse wrinkles. Abdominal ventrites with distinct microreticulation, strioles, and very fine sparse punctation.

Structures: Pronotum with distinct lateral bead. Base of prosternum and neck of prosternal process with distinct ridge, slightly rounded anteriorly. Blade of prosternal process lanceolate, relatively broad, slightly convex, with distinct lateral bead and few setae; neck and blade of prosternal process evenly joined. Abdominal ventrite 6 broadly rounded.

Male: Antennae simple or stout (Fig. 2). Protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of 18–27 and posterior row of 8 relatively short setae (Fig. 5D). Median lobe curved, with apex curved downwards and slightly rounded in lateral view and evenly tapering to the broadly pointed apex in ventral view. Paramere with distinct notch on its dorsal side and small, evidently separated subdistal part with a tuft of very dense, strong setae; proximal setae inconspicuous, strongly reduced in some specimens (Fig. 5A–C). Abdominal ventrite 6 with 5–16 long lateral striae on each side.

Holotype: TL-H 4.2 mm, TL 4.6 mm, MW 2.25 mm.

Female: Antennae simple. Pro- and mesotarsi not modified. Abdominal ventrite 6 without striae.

In some males, antennomeres 2–6 slightly thicker, stout. Some specimens have the dorsal microreticulation more strongly impressed. Two specimens from Sandaun are smaller than most of the Papua specimens (TL-H 3.3–3.65 mm, TL 3.7–4.1 mm, MW 1.75–1.95 mm) and have less dense subdistal setae on the paramere.

Papua: Pegunungan Bintang Regency and Papua New Guinea: Sandaun Province (Fig. 12).

Near Ok Bap, the species was collected in small creeks as well as in slowly flowing, sun exposed irrigation ditches along road.

The species is named after Ok Bap, where most of the specimens were collected. The name is an adjective in the nominative singular.

Papua: Jayawijaya Regency, Wamena, 04°03.6'S; 139°01.9'E, 2050 m a.s.l.

Holotype: male “IN, PA: Jayawijaya Regen., Baliem vall., 10km NE Wamena, forest above ‘Baliem vall. Resort’, 2050 m, 2–3.II.2015, 04°03.6'S, 139°01.9'E; J.Hájek & J.Šumpich leg” (NMPC). Paratypes: 2 males and 7 females with the same label as the holotype, one female with an additional label “M. Balke 7372” (MZB, NHMW, NMPC, ZSM). 6 males, 11 females “INDONESIA, Papua: Jayawijaya Distr., Ballem valley, 10km NE of Wamena, forest above “Baliem valley resort”, 04°03.6'S, 139°01.9'E, 2050 m; 2-3.ii.2015 J.Hájek & J.Šumpich leg.” (NHMW, NMPC, ZSM). 1 male “66 M. Balke” [green], “measured J. Parkin 43”, “Indonesia: Irian Jaya, N Wamena, Cerny, M. Balke: MB 66” (ZSM).

Beetle medium-sized; dark brown to piceous, with reddish brown pronotal sides; submatt; pronotum with distinct lateral bead; male antennomeres 2–6 slightly, but evidently enlarged, female antennomeres 2–6 stout; male protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta; male protarsomere 5 long and narrow, without concavity, with anterior row of 26 and posterior row of eight relatively short setae; median lobe curved, with apex curved downwards and slightly rounded in lateral view. The subspecies differs from the nominative subspecies in the modified antennae, in the shape and setation of the paramere, and in the more striated abdominal ventrite 6; some beetles are also somehow slightly more matt due to more strongly impressed dorsal microreticulation.

Size and shape: Beetle medium-sized (TL-H 3.75–4.5 mm, TL 4.1–4.9 mm, MW 2.0–2.3 mm), with oblong-oval habitus, broadest at elytral middle (Fig. 3). Coloration: As in nominative subspecies.

Surface sculpture: As in nominative subspecies apart from pronotum and elytra with evident, rather strongly impressed microreticulation, dorsal surface submatt.

Structures: As in nominative subspecies.

Male: Antennomeres 2–6 slightly, but evidently enlarged, antennomere 2 with slightly extended external upper angle (Fig. 3). Protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of 26 and posterior row of eight relatively short setae (Fig. 6D). Median lobe curved, with apex curved downwards and slightly rounded in lateral view and evenly tapering to the slightly truncate apex in ventral view. Paramere with distinct notch on dorsal side and small, evidently separated subdistal part with a tuft of very dense, strong setae; proximal setae inconspicuous (Fig. 6A–C). Abdominal ventrite 6 with numerous (16–22) long lateral striae on each side.

Holotype: TL-H 4.0 mm, TL 4.4 mm, MW 2.05 mm.

Female: Antennomeres 2–6 stout, in some specimens only slightly more slender than in males, antennomere 2 with slightly extended external upper angle; pro- and mesotarsi not modified and abdominal ventrite 6 without striae.

In some males, antennomeres 2–6 more strongly enlarged, in some others less strongly enlarged, similar to those of females.

Papua: Jayawijaya Regency. The subspecies is known only from the type locality (Fig. 12).

Near Wamena, the species was collected from wet ground with weak water flow and forest puddles, which turn to a small creek during rain (Figs 13–14).

The subspecies is named after our friend and colleague Jirí Hájek who collected almost all the specimens. The name is a noun in the genitive case.

Papua New Guinea: Sandaun Province, May River, 04°49.80'S; 141°38.17'E, above 2000 m a.s.l.

Holotype: male “M. Balke 662”, “Papua New Guinea: Sandaun, May River (WB47), 15.x.2003, K. Sagata, M. Balke: MB 662” (ZSM). Paratypes: 1 male, 2 females “Papua New Guinea: Sandaun, May River, 8.x.2003, 2627m, 4 49.779S 141 38.174E K. Sagata (WB47)”, male with an additional label “M. Balke 663” (ZSM). 1 male “M. Balke 664”, “Papua New Guinea: Sandaun: Sandaun, May River (WB47), 15.x.2003, K. Sagata, M. Balke: MB 664” (ZSM).

1 male “M. Balke 671”, “Papua New Guinea: Sandaun, Mekil (WB106), 14.x.2003, K. Sagata, M. Balke: MB 671” (ZSM). 1 male “M. Balke 679”, “Papua New Guinea: Sandaun, Mekil (WB106), 14.x.2003, K. Sagata, M, Balke: MB 679” (ZSM).

Beetle medium-sized; piceous, with brown head and sides of pronotum; submatt, with distinct punctation and microreticulation; male antennae simple; male protarsomere 4 with small (smaller than more laterally situated large seta), weakly curved anterolateral “hook-like” seta; male protarsomere 5 long and narrow, without concavity, with anterior and posterior rows of relatively short setae; median lobe curved, with apex curved downwards and slightly rounded in lateral view. The species is similar to the submatt representatives of the E. aipo-group with non-modified antennae but differs from them in non-modified male protarsomere 5. From E. okbapensis sp. n., it differs in the small and weakly curved anterolateral “hook-like” seta of the male protarsomere 4.

Size and shape: Beetle medium-sized (TL-H 3.6–4.65 mm, TL 3.75–5.1 mm, MW 1.9–2.4 mm), with oblong-oval habitus, broadest at elytral middle. Coloration: Head, pronotum and elytra dark brown to piceous, pronotal sides sometimes reddish brown; head appendages and legs reddish brown, distally darker (Fig. 4).

Surface sculpture: Head with relatively dense and coarse punctation (spaces between punctures 1–2 times size of punctures); diameter of punctures equal to diameter of cells of microreticulation. Pronotum with finer, sparser punctation, and more evenly distributed punctation than on head. Elytra with sparser punctation than on pronotum. Pronotum and elytra with distinct microreticulation, dorsal surface submatt. Head with microreticulation slightly stronger. Metaventrite, metacoxa, and abdominal ventrites distinctly microreticulate. Metacoxal plates with longitudinal strioles and transverse wrinkles; abdominal ventrites with strioles. Ventrum with inconspicuous punctation, more evident on metacoxal plates and two last abdominal ventrites.

Structures: Pronotum with distinct lateral bead. Base of prosternum and neck of prosternal process with distinct ridge, slightly rounded anteriorly. Blade of prosternal process lanceolate, relatively broad, slightly convex and smooth, with distinct lateral bead and few lateral setae; neck and blade of prosternal process evenly joined. Abdominal ventrite 6 broadly rounded.

Male: Antennae simple (Fig. 4). Protarsomere 4 with small (smaller than more laterally situated large seta), weakly curved anterolateral “hook-like” seta. Protarsomere 5 long and narrow, without concavity, ventrally with anterior row of 14–22 and posterior row of 4–9 relatively short setae (Fig. 7D). Median lobe curved, with apex curved downwards and slightly rounded in lateral view. Paramere with distinct notch on its dorsal side and small, evidently separated subdistal part with a tuft of very dense, strong setae; proximal setae inconspicuous (Fig. 7A–C). Abdominal ventrite 6 with 4–9 lateral striae on each side.

Holotype: TL-H 4.25 mm, TL 4.7 mm, MW 2.15 mm.

Female: Without evident differences in external morphology from males, except for non-modified pro- and mesotarsi and abdominal ventrite 6 without striae.

Two males from Mekil have dorsal punctation finer and microreticulation less strongly impressed, therefore, they are shinier. Shape and setation of the genitals are very similar to those of the May specimens but also difficult to estimate precisely since both beetles are teneral. For these reasons, they are considered to belong to the species but are not included into the type series.

Papua New Guinea: Sandaun Province. The species is known from two localities in the southern part of the province (Fig. 12).

The species is named after May River. The name is a noun in the nominative singular standing in apposition.

Papua: Pegunungan Bintang Regency, Borme, according to the original description.

Holotype: The holotype and 46 paratypes from the same locality have not been found. According to the original description (Balke 1998), they were deposited at the NHMW and had labels with the following data: Irian Jaya, Jayawijaya Province, Borme, 900 m, 18.viii.1992, IR 92#17, M. Balke leg. No beetles with such label data have been found in the collections of NHMW, ZSM, CGW, or in London. Moreover, the label data of this locality (17 from 1992) are wrongly given in the original descriptions not only for this species but also for Copelatus takime Balke, 1998: locality 17 is not Borme but Kali Takime, as the labels of the type specimens of C. takime state. There are four males (three in NHMW and one in CGW) with the geographical labels “IRIAN JAYA Zentralmassive 140°25'E, 04°24'S" and “14./17.viii.1992 Borme, 1900 m leg. Balke (11)”, one of which has a red holotype label. Therefore, perhaps, the holotype label was simply misquoted in the original description. However, since the type series, indicated in the original description, is very large (47 specimens), investigations on this subject are ongoing.

Paratypes: 2 males “IRIAN JAYA: Borme, Tarmlu, 1500 m 6.9.1993”, “ca. 140°25'E, 04°24'S leg. M. Balke (4)”, “Paratypus Copelatus ketembang Balke des. 1997” [red], one of them with an additional green label “M. Balke 3284” (NHMW). 3 males “IRIAN JAYA: Borme, Tarmlu, 1500 m, 6.ix.1993”, “ca. 140°25'E, 04°24'S leg. M. Balke (4-6)”, “Paratypus Copelatus ketembang Balke des. 1997” [red], one of them with two additional labels “M. Balke 3285” [green] and “M. Balke 6410” [green text] (NHMW). 4 males “IRIAN JAYA Zentralmassive 140°25'E, 04°24'S", “14./17.8.1992 Borme, 1900 m leg. Balke (11)”, “Paratypus Copelatus ketembang Balke des. 1997” [red] (CGW, NHMW). 1 male “IRIAN JAYA: 1.x.1993 Eme Gebiet Okloma, 1500 m”, “ca. 139°55'E, 04°14'S leg. M. Balke (28)”, “Paratypus Copelatus ketembang Balke des. 1997” [red] (NHMW). 5 males, 4 females “IRIAN JAYA, 7.9.1992 Kono, 1800 m 139°47'E, 04°21'S, leg. Balke (41)” (CGW, NHMW); the females might belong to two species, Exocelina ketembang and E. damantiensis (Balke, 1998).

Indonesia: Papua Province: Pegunungan Bintang Regency: 1 female “IRIAN JAYA Zentralmassive 140°25'E, 04°24'S", “14./17.8.1992 Borme, 1900 m leg. Balke (11)” (NHMW). 1 male, 1 female “IRIAN JAYA Zentralmassive 140°25'E, 04°24'S", “Borme, 1800 m 16.8.1992 leg. Balke (12, 12 A)” (NHMW). Papua New Guinea: Sandaun Province: 1 male “M. Balke 670”, “Papua New Guinea: Sandaun, Mekil (WB106), 14.x.2003, K.Sagata, M. Balke: MB 670” (ZSM). 1 male “M. Balke 680”, “Papua New Guinea: Sandaun, Mekil (WB106), 14.x.2003, K. Sagata, M. Balke: MB 680” [04°48.742S 141.39.075E] (ZSM). 1 male “M. Balke 3727” [green], “Papua New Guinea: Sandaun, Ofektaman, 820 m, 17.x.2008, 5.04.113S 141.35.841E, Ibalim (PNG 190)” (ZSM).

Indonesia: Papua Province: Pegunungan Bintang Regency: 1 female “IR 92#17B: West New Guinea, Tanime, 1600 m, 20.viii.1992, Balke” (NHMW); this female might belong to three species: Exocelina ketembang, E. danae (Balke, 1998) and E. damantiensis. 1 female “IRIAN JAYA, 7.ix.1992 Kono, 1800m 139°47'E, 04°21'S, leg. Balke (41) (CGW), the female might belong to two species: Exocelina ketembang and E. damantiensis. Papua New Guinea: Sandaun Province: 3 females “Papua New Guinea: Sandaun, MekilK [sic!], 1718 m, 14.x.2003, 4 48.742S 141 39.075E, K. Sagata (WB 106)” (ZSM); these females might belong to two species: E. sandaunensis Shaverdo & Balke, 2014 and E. ketembang. 7 females “Papua New Guinea: Sandaun, Ofektaman, 820 m, 17.x.2008, 5.04.113S 141.35.841E, Ibalim (PNG 190)” (ZSM); these females might belong to three species: E. sandaunensis, E. aipomek (Balke, 1998), and E. ketembang.

Beetle medium-sized (TL-H 3.9–4.35 mm); oblong-oval; dark brown to piceous, sometimes with reddish brown pronotal sites and head anteriorly; shiny, with very fine punctation and weakly impressed microreticulation; pronotum with distinct lateral bead; male antennae simple (Fig. 8); male protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta; male protarsomere 5 long and narrow, without concavity, with anterior row of 21 and posterior row of six relatively short setae; median lobe strongly curved, sharply pointed in lateral view, evenly tapering, with narrowly rounded apex in ventral view; paramere with notch on its dorsal side and small, less evidently separated subdistal part with a tuft of dense setae; proximal setae inconspicuous (Fig. 10A–D). For complete description, see Balke (1998).

Papua: Pegunungan Bintang Regency and PNG: Sandaun Province (Fig. 12).

Papua: Pegunungan Bintang Regency, Borme, ca. 04°24'S; 140°25'E, 1200 m a.s.l.

Holotype: male “IRIAN JAYA: Borme ca. 140°25'E, 04°24'S 1200 m, 2.9.1993 leg. M. Balke (1)”, “HOLOTYPUS” [red], “Copelatus talaki Balke des. 1997” [red] (NHMW). Paratypes: Three females with the same label as the holotype and additionally with red labels “Paratypus Copelatus talaki Balke des. 1997”, one of them with two additional labels “M. Balke 3294” [green] and “M. Balke 6415” [green text] (NHMW).

Beetle small (TL-H 3.25–3.4 mm); oblong-oval; reddish brown to brown, with paler head and pronotum, with fine punctation and weakly impressed microreticulation, shiny; pronotum with distinct lateral bead; male antennae simple (Fig. 9); male protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta; male protarsomere 5 long and narrow, without concavity, with anterior row of 14 and posterior row of seven relatively short setae; median lobe strongly curved, sharply pointed in lateral view, evenly tapering, with broadly pointed apex in ventral view; paramere with notch on its dorsal side and small, less evidently separated subdistal part with a tuft of dense setae; proximal setae inconspicuous (Fig. 11A–D). For complete description, see Balke (1998).

Papua: Pegunungan Bintang Regency (Fig. 12). The species is known only from the type material.