Exocelina ekpliktiki Shaverdo, Surbakti & Balke, 2021

Shaverdo, Helena, Surbakti, Suriani, Sumoked, Bob & Balke, Michael, 2021, Seven new species of the Exocelina ekari group from New Guinea central and coastal mountains (Coleoptera, Dytiscidae, Copelatinae), ZooKeys 1026, pp. 45-67 : 45

Exocelina ekpliktiki Shaverdo, Surbakti & Balke sp. nov. Figures 11 , 12 , 15

Exocelina nr. oceai #6504: Toussaint et al. 2021: figs 3-6.

Type locality.

Indonesia: Papua Province, Puncak Regency, south from Iratoi , 03°54'20.4"S, 137°12'03.2"E, 378 m a.s.l.

Type material.

Holotype: male " Indonesia: Papua, S Iratoi, forest, 378m, 22.v.2015, -3,3904028 137,32009999, Pele & Sumoked (Pap037)" ( MZB) .

Paratypes: Puncak Regency: 16 males, 8 females with the same label as the holotype ( MZB, KSP) . 3 males " Indonesia: Papua, S Iratoi, forest, 378m, 22.v.2015, -3,3904028031975 137,320099985226, Pele & Sumoked (Pap037)", one male an additional label “KSP6983” [green text] ( KSP) . 5 males, 2 females " Indonesia: Papua, S Iratoi, forest, 553m, 22.v.2015, -3,3919226937 137,3235277, Pele & Sumoked (Pap038)" ( KSP) . 1 male, 1 female " Indonesia: Papua, S Iratoi, forest, 553m, 22.v.2015, -3,39192269369959 137,323527764528, Pele & Sumoked (Pap038)", with additional green text labels “6989” and “6988”, respectively ( KSP) . 17 males, 11 females " Indonesia: Papua, S Iratoi, forest, 450m, 23.v.2015, near -3,39192 137,323527764528, Pele & Sumoked (Pap039)" ( MZB, KSP) . 2 males " Indonesia: Papua, S Iratoi, forest, 450m, 23.v.2015, near -3,391922694 137,323527764528, Pele & Sumoked (Pap039)", with additional green text labels “6986” and “6987” ( KSP) . 13 males, 5 females " Indonesia: Papua, Wano Land , red clay creek nr cave, 1100m, 3.ix.2014, nr -3.587955 137.5114945, Bennji (Pap024)", one male an additional label “6517” [green text] ( MZB, KSP) .

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] ( MZB, KSP) . 6 males, 6 females " Indonesia: Papua, Rouaffer, Iratoi , hill in forest, 164m, 6.ix.2014, -3,2403086 137,3329744, Pele & Sumoked (Pap028)", two males with additional green text labels “6504” and “6505” ( KSP) .

Description.

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. 11 ), some specimens, especially teneral slightly egg-shaped.

Colouration: Dorsally dark brown to piceous, with paler, reddish brown anterior half of head and lateral sides of pronotum (Fig. 11 ). Head dark brown posteriorly and largely (to half) reddish brown anteriorly; pronotum dark brown to piceous, with reddish to reddish brown lateral sides, sometimes also narrowly anteriorly and posteriorly leaving dark brown disc; elytra dark brown to piceous, with reddish brown sutural lines; head appendages yellow, legs yellowish red to reddish brown. Teneral specimens paler, to pale brown, with yellow anterior half of head and pronotal sides.

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. 12A ). Median lobe with distinctly discontinuous outline; in lateral view, almost straight, with curved downwards, broadly pointed apex; in ventral view, with weak submedian constriction, distal part only slightly narrower than proximal one, and evenly, shallowly concave apex (Fig. 12B, C ). Paramere with strong notch on dorsal side and subdistal part short and small; subdistal setae long, dense, curved at apex, few lower ones slightly flattened; proximal setae numerous, dense, but weaker than subdistal ones (Fig. 12D ). Abdominal ventrite 6 with 5-10 lateral striae on each side.

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

Variability.

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.

Affinities.

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 Shaverdo et al., 2012 and, especially, to E. weylandensis Shaverdo et al., 2012. However, it differs distinctly from them in presence of the pronotal bead and in that, it is similar to E. oceai Shaverdo et al., 2012 and can be as well as distinguished from the co-occurring species, E. bewaniensis and E. oraia sp. nov.; from E. oraia sp. nov. also by not having modified male antennae.

Distribution.

Indonesia: Papua Province. This species is known only from the Wano Land (Fig. 15 ).

Habitat.

The specimens were collected from small forest creeks.

Etymology.

The species name Exocelina ekpliktiki derives from Greek εκπληκτικός (feminine εκπληκτική) meaning fantastic. The name is an adjective in the nominative singular.

Figures

Figure 15. Map of the western part of New Guinea showing the species distribution.

Figures 11, 12. Exocelina ekpliktiki sp. nov., holotype 11 habitus and colouration 12 male structures A right protarsomeres 4 and 5 in ventral view B median lobe in ventral view C median lobe in lateral view D right paramere in external view.