Research Article |
Corresponding author: Helena Shaverdo ( shaverdo@mail.ru ) Academic editor: Mariano Michat
© 2021 Helena Shaverdo, Suriani Surbakti, Bob Sumoked, Michael Balke.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Shaverdo H, Surbakti S, Sumoked B, Balke M (2021) Seven new species of the Exocelina ekari group from New Guinea central and coastal mountains (Coleoptera, Dytiscidae, Copelatinae). ZooKeys 1026: 45-67. https://doi.org/10.3897/zookeys.1026.61554
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Seven new species of the genus Exocelina Broun, 1886 are described from three different mountain ranges of New Guinea: E. foja sp. nov., E. riberai sp. nov., E. apistefti sp. nov., and E. waaf sp. nov. from the Foja Mountains; E. hudsoni sp. nov. from the Cyclops Mountains; E. ekpliktiki sp. nov. and E. oraia sp. nov. from Wano Land. All of them are placed into the E. ekari group based on the structure of their male genitalia. The species are characteristic dytiscid elements of the fauna of northern cost and the western part of central orogen of New Guinea. Two taxonomic notes are presented: Exocelina athesphati is a correct name for the recently described Exocelina athesphatos Shaverdo et al., 2020; Exocelina bacchus Balke, nom. nov. is a replacement name for Exocelina bacchusi (Balke, 1998), formerly Copelatus (Papuadytes) bacchusi Balke, 1998, a junior homonym of Copelatus bacchusi Wewalka, 1981.
Australasia, distribution, Exocelina, new species, systematics
Even after more than 20 years of research on New Guinea Exocelina diving beetles, the island’s rugged mountain regions continue to reveal new species (
All seven new species were found to belong to the E. ekari group. To date, this, the largest Exocelina species group, contains 63 species; 152 Exocelina species are now described from New Guinea and 209 species worldwide.
The material studied is housed in the following collections:
KSP Koleksi Serangga Papua, at the Biology Department of Universitas Cenderawasih (UNCEN), Wamena, Papua, Indonesia;
Our methods follow those described in detail in our previous articles (
Exocelina nr. pseudosoppi
#7286:
Indonesia: Papua Province, Sarmi Regency, Foja Mts, 02°34'18.6"S, 138°43'02.1"E, 1700 m a.s.l.
Holotype: male “Indonesia: Papua, Foja Mountains, bog camp, 1700m, 23.v.-3.vi.2016, -2.571839 138.717250, Sumoked (Pap058)” (
Paratypes: 26 males, 19 females with the same label as the holotype, three males with additional handwritten labels “creek A”, “creek C” and “creek D” (
Body size and form: Beetle small: TL-H 3.30–3.85 mm, TL 3.70–4.30 mm, MW 1.80–2.10 mm (holotype: TL-H 3.85 mm, TL 4.30 mm, MW 2.10 mm), with oblong-oval habitus (Fig.
Colouration: Dorsally dark brown to piceous, with paler head and sides of pronotum (Fig.
Surface sculpture: Shiny dorsally, with fine punctation and microreticulation. Head with dense and coarse punctation (spaces between punctures 0–3 times size of punctures), distinctly finer and sparser anteriorly and posteriorly; diameter of punctures equal to diameter of cells of microreticulation. Pronotum with distinctly finer and sparser punctation than on head. Elytra with very sparse and fine punctation, almost invisible. Pronotum and elytra with weakly impressed microreticulation; head with stronger microreticulation. Metaventrite and metacoxa distinctly but weakly microreticulate, metacoxal plates with longitudinal strioles and transverse wrinkles. Abdominal ventrites with weak microreticulation, strioles, and fine sparse punctation, coarser and denser on two terminal abdominal ventrites.
Structures: Pronotum with narrow lateral bead. Base of prosternum and neck of prosternal process with ridge, slightly rounded anteriorly. Blade of prosternal process lanceolate, relatively narrow, slightly convex medially, with distinct bead and few setae. Abdominal ventrite 6 broadly rounded apically.
Male: Antenna simple. Pro- and mesotarsomeres 1–3 not dilated, narrow. Protarsomere 4 cylindrical, narrow, with medium-sized, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of eleven and posterior row of six short setae (Fig.
Female: Pro- and mesotarsi not modified. Abdominal ventrite 6 without striae.
The species evidently belongs to the E. ekari group due to the discontinuous outline of its median lobe. Within the group, it can be placed close to E. oceai
Indonesia: Papua Province. This species is known only from Foja Mountains, from and near the type locality (Fig.
The specimens were collected from small, shallow forest creeks.
The species is named after Foja Mountains. The name is a noun in the nominative singular standing in apposition.
Exocelina nr. brahminensis
#7287:
Indonesia: Papua Province, Sarmi Regency, Foja Mts, 02°34'18.6"S, 138°43'02.1"E, 1700 m a.s.l.
Holotype: male “Indonesia: Papua, Foja Mountains, bog camp, 1700m, 23.v.-3.vi.2016, -2.571839 138.717250, Sumoked (Pap058)”, “7287” [green text] (
Paratypes: 2 females with the same label as the holotype (KSP). 1 male, 1 female “Indonesia: Papua, Foja Mountains, river camp, 1600m, 23.v.-3.vi.2016, -2.561006 138.711487, Sumoked (Pap059)” (
Body size and form: Beetle small: TL-H 3.45–3.7 mm, TL 3.8–4.05 mm, MW 1.85–2 mm (holotype: TL-H 3.5 mm, TL 3.9 mm, MW 1.9 mm), with oblong-oval habitus (Fig.
Colouration: Dorsally piceous, with paler lateral sides of pronotum (Fig.
Surface sculpture: Shiny dorsally, with fine microreticulation and almost invisible punctation on elytra. Head with dense and coarse punctation (spaces between punctures 0–3 times size of punctures), distinctly finer and sparser anteriorly and posteriorly; diameter of punctures equal to diameter of cells of microreticulation. Pronotum with distinctly finer and sparser punctation than on head. Elytra with very sparse and fine punctation, almost invisible. Elytra with weakly impressed microreticulation; pronotum and especially head with stronger microreticulation. Metaventrite and metacoxa distinctly but weakly microreticulate, metacoxal plates with longitudinal strioles and transverse wrinkles. Abdominal ventrites with weak 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 ridge, slightly rounded anteriorly. Blade of prosternal process lanceolate, relatively narrow, slightly convex medially, with distinct bead and few setae. Abdominal ventrite 6 broadly rounded apically.
Male: Antenna simple. Pro- and mesotarsomeres 1–3 not dilated, narrow. Protarsomere 4 cylindrical, narrow, with medium-sized, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of 13 and posterior row of six short setae (Fig.
Female: Pro- and mesotarsi not modified. Abdominal ventrite 6 without striae.
The species evidently belongs to the E. ekari group due to the discontinuous outline of its median lobe. The species is very similar to E. brahminensis
Indonesia: Papua Province. This species is known only from Foja Mountains, from and near the type locality (Fig.
The specimens were collected from small, shallow forest creeks.
The species name apistefti derives from Greek απίστευτος (feminine απίστευτη) meaning unbelievable. The name is an adjective in the nominative singular.
Exocelina
“Foja” #7282:
Indonesia: Papua Province, Sarmi Regency, Foja Mts, N Waaf Village, 02°22'29.6"S, 138°44'19.9"E, 115 m a.s.l.
Holotype: male “Indonesia: Papua, Foja Mountains N foot, N Waaf vill, 115m, 23.v.-3.vi.2016, -2.374874 138.738855, Sumoked (Pap060)” (
Paratypes: 3 males, 5 females with the same label as the holotype (
Body size and form: Beetle small to medium-sized: TL-H 3.45–3.85 mm, TL 3.8–4.3 mm, MW 1.85–2.1 mm (holotype: TL-H 3.6 mm, TL 4.1 mm, MW 1.9 mm), with oblong-oval habitus (Fig.
Colouration: Dorsally dark brown to piceous, usually with paler, reddish brown, head and pronotum (Fig.
Surface sculpture: Shiny dorsally, with inconspicuous, almost invisible elytral punctation and weakly impressed microreticulation. Head with relatively fine and sparse punctation (spaces between punctures 1–4 times size of punctures); diameter of punctures smaller than diameter of cells of microreticulation. Pronotum with finer, sparser, and more evenly distributed punctation than on head, often inconspicuous. Elytra with very sparse and fine punctation, almost invisible. Elytra with weakly impressed microreticulation; pronotum and especially head with stronger microreticulation. Metaventrite and metacoxa distinctly but weakly microreticulate, metacoxal plates with longitudinal strioles and very weak transverse wrinkles. Abdominal ventrites with weak microreticulation, strioles, and punctation visible only on two last abdominal ventrites.
Structures: Pronotum without lateral bead, in some specimens (especially characteristic for females) with bead traces or even with narrow bead on lateral sides of pronotum. 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. Abdominal ventrite 6 broadly rounded.
Male: Antenna simple. Pro- and mesotarsomeres 1–3 not dilated, narrow. Protarsomere 4 cylindrical, narrow, with medium-sized, thick, distinctly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of ten and posterior row of five short setae (Fig.
Female: Pro- and mesotarsi not modified. Abdominal ventrite 6 without lateral striae. Bead traces or even with narrow bead on lateral margins pronotum present in majority of females.
The new species evidently belongs to the E. ekari group due to the discontinuous outline of its median lobe. The species is similar to E. pinocchio Shaverdo & Balke, 2014 in general appearance and shape of median lobe, but differs from it in more straight apical prolongation of the median lobe and in subquadrate, large and broad subdistal part of the paramere (distinctly more elongate in E. pinocchio) and its setation.
Indonesia: Papua Province. This species is known only from Foja Mountains, from and near the type locality (Fig.
The specimens were collected from shaded waterholes on a riverbank.
The species is named to honour Dr Ignacio Ribera Galán, a leading water beetle specialist and our dear colleague who passed away on 15 April 2020. The name is a noun in the genitive case.
Exocelina nr. utowaensis
#7281:
Indonesia: Papua Province, Sarmi Regency, Foja Mts, N Waaf Village, 02°22'29.6"S, 138°44'19.9"E, 115 m a.s.l.
Holotype: male “Indonesia: Papua, Foja Mountains N foot, N Waaf vill, 115m, 23.v.-3.vi.2016, -2.374874 138.738855, Sumoked (Pap060)” (
Paratypes: 7 males, 2 females with the same label as the holotype, one male with an additional green text label “7281” (
Body size and form: Beetle small to medium-sized: TL-H 3.55–3.75 mm, TL 3.9–4.2 mm, MW 1.95–2.0 mm (holotype: TL-H 3.65 mm, TL 4.1 mm, MW 1.95 mm), with oblong-oval habitus (Fig.
Colouration: Dorsally piceous, with paler lateral sides of pronotum (Fig.
Surface sculpture: Shiny dorsally, with inconspicuous, almost invisible elytral punctation and weakly impressed microreticulation. Head with uneven, sparse punctation (spaces between punctures 1–4 times size of punctures); diameter of punctures smaller than or almost equal to diameter of cells of microreticulation; punctation sparser and finer anteriorly and posteriorly. Pronotum with distinctly finer, sparser, and more evenly distributed punctation than on head. Elytra with very sparse and fine punctation, almost invisible. Elytra and pronotum with weakly impressed microreticulation; head with stronger microreticulation. Metaventrite and metacoxa distinctly but weakly microreticulate, metacoxal plates with longitudinal strioles and transverse wrinkles. Abdominal ventrites with weak microreticulation, strioles, and fine punctation.
Structures: Pronotum without lateral bead. Base of prosternum and neck of prosternal process with distinct ridge, slightly rounded anteriorly. Blade of prosternal process lanceolate, narrow, convex, with distinct lateral bead and few setae. Abdominal ventrite 6 concave apically.
Male: Antenna simple (Fig.
Female: Pro- and mesotarsi not modified. Abdominal ventrite 6 slightly concave, without lateral striae.
The new species evidently belongs to the E. ekari group due to the discontinuous outline of its median lobe. The species is very similar to E. utowaensis
Indonesia: Papua Province. This species is known only from the type locality in Foja Mountains (Fig.
The specimens were collected from shaded waterholes on a riverbank.
The species is named after Waaf Village. The name is a noun in the nominative singular standing in apposition.
Since five different species are now known from the Foja Mountains, it is worth providing a key to identify them. All species belong to the E. ekari group and are similar to each other in their external morphology. Therefore, the key is based mostly on characters of the male genitalia. Because of that, females cannot be often assigned to species and should be identified in association with males from the same population.
1 | Pronotum with narrow lateral bead. Median lobe and paramere as in Fig. |
foja |
– | Pronotum without lateral bead, sometimes (especially in females) with bead traces or even narrow bead, in this case, several specimens of population should be checked | 2 |
2 | Abdominal ventrite 6 concave apically. Median lobe and paramere as in Fig. |
waaf |
– | Abdominal ventrite 6 broadly rounded | 3 |
3 | Apex of median lobe very strongly protruding, forming long, thin prolongation in lateral view (Fig. |
riberai |
– | Apex of median lobe broad, short, and pointed at tip in lateral view | 4 |
4 | Apex of median lobe broader in lateral view; in ventral view, deeply and narrowly concave (Fig. |
apistefti |
– | Apex of median lobe narrower in lateral view; in ventral view, shallowly and evenly concave (Figs 21–23C, D in |
bewaniensis |
Only two species are known from the Cyclops Mountains: E. cyclops Shaverdo & Balke, 2018 from the E. casuarina group and the newly described E. hudsoni sp. nov. from the E. ekari group. They can be easily distinguished due to smaller body size of E. cyclops (TL-H 3.0–3.25 mm), its reddish dorsal colouration, unmodified male antennae, and different structure of the male genitalia (
Indonesia: Papua Province, Jayapura Regency, Cyclops Mts, 1880 m a.s.l.
Holotype: male “Indonesia: Papua, Cyclops Mountains, below summit, 1880m, ii.201, Sentani Naturalist Club (Pap70)” (
Paratypes: 7 females with the same label as the holotype (
Body size and form: Beetle small to medium-sized: TL-H 3.4–3.75 mm, TL 3.75–4.2 mm, MW 1.8–2.05 mm (holotype: TL-H 3.4 mm, TL 3.8 mm, MW 1.8 mm), with oblong-oval habitus (Fig.
Colouration: Dorsally piceous, with paler head and pronotum (Fig.
Surface sculpture: Submatt dorsally, with inconspicuous elytral punctation and strongly impressed dorsal microreticulation. Head with sparse central punctation (spaces between punctures 1–4 times size of punctures), denser towards eyes; diameter of punctures smaller than diameter of cells of microreticulation; punctation relatively shallow. Pronotum with distinctly finer, sparser, and more evenly distributed punctation than on head. Elytra with very sparse and fine punctation, almost invisible. Dorsal surface with strongly impressed microreticulation, microreticulation weaker on elytra and stronger on pronotum and head. Metaventrite and metacoxa distinctly but weakly microreticulate, metacoxal plates with longitudinal strioles and very weak transverse wrinkles. Abdominal ventrites with weak microreticulation, strioles, and almost invisible punctation.
Structures: Pronotum with lateral bead. Base of prosternum and neck of prosternal process with distinct ridge, slightly rounded anteriorly. Blade of prosternal process lanceolate, relatively broad, convex, with distinct lateral bead and few setae. Abdominal ventrite 6 broadly rounded.
Male: Antennomeres 4–10 slightly but distinctly enlarged (Fig.
Female: Antennomeres 4–10 stout. Pro- and mesotarsi not modified. Abdominal ventrite 6 without lateral striae.
The species evidently belongs to the E. ekari group due to the discontinuous outline of its median lobe. The species is very similar to E. brahminensis and E. apistefti sp. nov. in general structure of male genitalia, especially in the sharply pointed median notch tip of paramere, but differs from them in submatt dorsal surface due to stronger microreticulation, presence of pronotal bead, enlarged antennomeres 4–10, shape of the median lobe, and setation of the paramere.
Indonesia: Papua Province. This species is known only from the type locality in Cyclops Mountains (Fig.
The specimens were collected from small puddles at low spot of a small ravine.
This species is named after Hudson Wild, a most dedicated naturalist and community worker in Papua. The name is a noun in the genitive case.
Ten species are now recorded from the Wano Land: E. sumokedi of the E. casuarina group, six species, mentioned in the Introduction, from the complex close to the E. ekari group (
Exocelina nr. oceai
#6504:
Indonesia: Papua Province, Puncak Regency, south from Iratoi, 03°54'20.4"S, 137°12'03.2"E, 378 m a.s.l.
Holotype: male “Indonesia: Papua, S Iratoi, forest, 378m, 22.v.2015, -3,3904028 137,32009999, Pele & Sumoked (Pap037)” (
Paratypes: Puncak Regency: 16 males, 8 females with the same label as the holotype (
Puncak Jaya Regency. 3 males “Indonesia: Papua, S Iratoi, forest, 220m, 21.v.2015, -3,38095162063837 137,311441982164, Pele & Sumoked (Pap036)”, one male an additional label “6982” [green text] (
Body size and form: Beetle small: TL-H 2.95–3.35 mm, TL 3.35–3.65 mm, MW 1.6–1.8 mm, excluding the locality Pap024, (holotype: TL-H 3.15 mm, TL 3.55 mm, MW 1.7 mm), with oblong-oval habitus (Fig.
Colouration: Dorsally dark brown to piceous, with paler, reddish brown anterior half of head and lateral sides of pronotum (Fig.
Surface sculpture: Shiny dorsally, with inconspicuous, almost invisible elytral punctation and weakly impressed microreticulation. Head with relatively sparse punctation (spaces between punctures 1–3 times size of punctures), evidently finer and sparser anteriorly and posteriorly; diameter of larger punctures almost equal to diameter of cells of microreticulation. Pronotum with finer, sparser, and more evenly distributed punctation than on head, often inconspicuous. Elytra with very sparse and fine punctation, almost invisible. Pronotum and elytra with weakly impressed microreticulation, sometimes stronger on pronotal sides; head with microreticulation much stronger. Metaventrite and metacoxa distinctly microreticulate, metacoxal plates with longitudinal strioles and transverse wrinkles. Abdominal ventrites with distinct microreticulation, strioles, and very fine and sparse punctation.
Structures: Pronotum with distinct but narrow lateral bead, in some specimens reduced at posterior angles. Base of prosternum and neck of prosternal process with distinct ridge, slightly rounded anteriorly. Blade of prosternal process lanceolate, relatively narrow, slightly convex, with distinct lateral bead and few setae. Abdominal ventrite 6 broadly rounded.
Male: Antenna simple. Pro- and mesotarsomeres 1–3 narrow. Protarsomere 4 narrow, with medium-sized, slightly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of 13 and posterior row of four short, pointed setae (Fig.
Female: Pro- and mesotarsi not modified. Abdominal ventrite 6 without lateral striae.
Beetles from the locality Pap024 are larger (TL-H 3.25–3.65 mm, TL 3.55–4.0 mm, MW 1.75–2.0 mm), with distinctly larger and more robust median lobe and paramere, though of the shape and setation of the median lobe and paramere are the same.
The species evidently belongs to the E. ekari group due to the discontinuous outline of its median lobe. Based on body size and form, colouration, dorsal surface sculpture, shape of anterolateral hook-like seta of the protarsomere 4, and shape and setation of genitalia, the new species is very similar to E. soppi
Indonesia: Papua Province. This species is known only from the Wano Land (Fig.
The specimens were collected from small forest creeks.
The species name ekpliktiki derives from Greek εκπληκτικός (feminine εκπληκτική) meaning fantastic. The name is an adjective in the nominative singular.
Exocelina nr. irianensis
#6520:
Indonesia: Papua Province, Puncak Jaya Regency, Puluk area, 03°39'37.0"S, 137°31'14.7"E, 1320 m a.s.l.
Holotype: male “Indonesia: Papua, Wano Land, Puluk, 1320m, 1.ix.2014, -3.660272 137.5207436, Bennji (Pap020)” (
Body size and form: Beetle small to medium-sized: TL-H 3.45–3.85 mm, TL 3.8–4.25 mm, MW 1.85–2.1 mm (holotype: TL-H 3.6 mm, TL 4 mm, MW 1.95 mm), with oblong-oval habitus (Fig.
Colouration: Dorsally piceous (Fig.
Surface sculpture: Shiny dorsally, with invisible elytral punctation and weakly impressed microreticulation. Head with relatively sparse punctation (spaces between punctures 1–3 times size of punctures), evidently finer and sparser anteriorly and posteriorly; diameter of punctures smaller than diameter of cells of microreticulation. Pronotum with distinctly finer, sparser, and more evenly distributed punctation than on head, often inconspicuous. Elytra with extremely sparse and fine punctation, often invisible. Pronotum and elytra with weakly impressed microreticulation; head with microreticulation much stronger. Metaventrite and metacoxa distinctly but weakly microreticulate, metacoxal plates with longitudinal strioles and very weak transverse wrinkles. Abdominal ventrites with distinct but weak microreticulation, strioles, and extremely fine and sparse, often invisible punctation, more distinct on abdominal ventrite 6.
Structures: Pronotum without lateral bead, in some specimens (especially characteristic for females) with bead traces or even with narrow bead on lateral sides of pronotum. Base of prosternum and neck of prosternal process with distinct ridge, slightly rounded anteriorly. Blade of prosternal process lanceolate, relatively narrow, slightly convex, with distinct lateral bead and few setae. Abdominal ventrite 6 broadly rounded.
Male: Antenna modified (Fig.
Female: Pro- and mesotarsi not modified. Abdominal ventrite 6 without lateral striae. Bead traces or even with narrow bead on lateral margins pronotum present in majority of females.
The species evidently belongs to the E. ekari group due to the discontinuous outline of its median lobe. The new species is very similar to E. irianensis
The specimens were collected from small forest creeks.
The species name oraia derives from Greek ωραίος (feminine ωραία) meaning nice, lovely. The name is an adjective in the nominative singular.
Indonesia: Papua Province: Puncak Jaya Regency (first record): 2 male, 1 female “Indonesia: Papua, Wano Land, creek @ jungle helipad, 870m, 4.ix.2014, -3,584077 137,5042947, Bennji (Pap027)”, one male an additional label “6527” [green text] (KSP). 1 male “Indonesia: Papua, S Iratoi, forest, 168m, 24.v.2015, -3,36070714518427 137,301383111625 (Pap040) Bennji” (KSP).
Papua New Guinea: Sandaun Province; Indonesia: Papua Province: Sarmi, Mamberano Raya, Nabire/Paniai, and Puncak Jaya regencies. The present records confirm that this morphologically variable species is broadly distributed in the central-northern part of western New Guinea.
The correct name for Exocelina athesphatos Shaverdo et al., 2020 is Exocelina athesphati since the species epithet athesphatos should be feminine.
Copelatus (Papuadytes) bacchusi Balke, 1998, not Copelatus bacchusi Wewalka, 1981.
We provide a replacement name for Exocelina bacchusi (Balke, 1998), described as Copelatus (Papuadytes) bacchusi Balke, 1998, since the species name of the latter is preoccupied by
We are grateful to Dr H. Schillhammer (Vienna) for the photographs and to Dr Dimitrios N. Avtzis (Trilofos, Thessaloniki) for his help with the Greek names. Specimens were loaned from
Financial support for the study was provided by the FWF (Fonds zur Förderung der wissenschaftlichen Forschung – the Austrian Science Fund) through the projects P 24312-B17 and P 31347-B25 to Helena Shaverdo. Michael Balke was supported by the German Science Foundation (DFG BA2152/11-1, 11-2, 19-1, 19-2). We are grateful for the generous support from the “SNSB-Innovativ” scheme, funded by the Bayerisches Staatsministerium für Wissenschaft und Kunst.