Exocelina foja 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 foja Shaverdo, Surbakti & Balke sp. nov. Figures 1 , 5 , 15

Exocelina nr. pseudosoppi #7286: Toussaint et al. 2021: figs 3-6.

Type locality.

Indonesia: Papua Province, Sarmi Regency, Foja Mts , 02°34'18.6"S, 138°43'02.1"E, 1700 m a.s.l.

Type material.

Holotype: male " Indonesia: Papua, Foja Mountains , bog camp, 1700m, 23.v.-3.vi.2016, -2.571839 138.717250, Sumoked (Pap058)" ( MZB) .

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" ( MZB, KSP) . 1 male, 6 females " Indonesia (1700A): Papua, Foja Mountains , bog camp, 1700m, 23.v.-3.vi.2016, -2.571839 138.717250, Sumoked (Pap058)" ( KSP) . 4 males, 5 females " Indonesia (1700B): Papua, Foja Mountains , bog camp, 1700m, 23.v.-3.vi.2016, -2.571839 138.717250, Sumoked (Pap058)" ( MZB, KSP) . 2 males, 3 females " Indonesia (1700D): Papua, Foja Mountains , bog camp, 1700m, 23.v.-3.vi.2016, -2.571839 138.717250, Sumoked (Pap058)" ( KSP) . 13 males, 10 females " Indonesia: Papua, Foja Mountains , bog camp, 1700m, 23.v.-3.vi.2016,", " -2.571839 138.717250, Sumoked (Pap058)", two females with additional green text labels “7357” and “7358” ( MZB, KSP) . 2 males, 4 females " Indonesia: Papua, Foja Mountains , river camp, 1600m, 23.v.-3.vi.2016, -2.561006 138.711487, Sumoked (Pap059)", one male with an additional handwritten label "forest near bog camp", the other male with an additional green text label “7286” ( MZB, KSP) .

Description.

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. 1 ).

Colouration: Dorsally dark brown to piceous, with paler head and sides of pronotum (Fig. 1 ). Head more or less uniformly dark brown to reddish brown, darker around eyes, or slightly paler anteriorly; pronotum dark brown to piceous on disc and distinctly paler (to yellowish red) anteriorly, posteriorly, and especially laterally; dark area on disc sometimes represented just as median band; elytra dark brown to piceous, with reddish brown sutural lines; head appendages and legs yellowish red to reddish brown. Teneral specimens paler.

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. 5A ). Median lobe with distinctly discontinuous outline; in lateral view, almost straight, with apex broad, curved downwards, and sharply pointed at tip; in ventral view, with distinct submedian constriction, distal part narrower than proximal one, apex truncate (Fig. 5B, C ). Paramere with strong notch on dorsal side and subdistal part relatively large and elongate; subdistal setae very few, dense and flattened: three upper longer, thinner, curved at apex and four lower shorter, almost straight, thicker; proximal setae hair-like, numerous, dense, but distinctly more inconspicuous than subdistal ones (Fig. 5D ). Abdominal ventrite 6 broadly rounded, with 5-9 lateral striae on each side.

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

Affinities.

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 Shaverdo et al., 2012 due to presence of the pronotal lateral bead. Shape of its median lobe is similar to that of E. pseudosoppi Shaverdo et al., 2012; setation of the paramere is very characteristic.

Distribution.

Indonesia: Papua Province. This species is known only from Foja Mountains , from and near the type locality (Fig. 15 ) .

Habitat.

The specimens were collected from small, shallow forest creeks.

Etymology.

The species is named after Foja Mountains. The name is a noun in the nominative singular standing in apposition.

Figures

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

Figures 1 - 4. Habitus and colouration of holotype 1 Exocelina foja sp. nov. 2 E. waaf sp. nov. 3 E. riberai sp. nov. 4 E. apistefti sp. nov.

Figures 5, 6. 5 Exocelina foja sp. nov., holotype 6 E. waaf sp. nov., holotype 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.