Exocelina waaf 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 waaf Shaverdo, Surbakti & Balke sp. nov. Figures 2 , 6 , 15

Exocelina nr. utowaensis #7281: Toussaint et al. 2021: figs 3-6.

Type locality.

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.

Type material.

Holotype: male " Indonesia: Papua, Foja Mountains N foot, N Waaf vill, 115m, 23.v.-3.vi.2016, -2.374874 138.738855, Sumoked (Pap060)" ( MZB) .

Paratypes: 7 males, 2 females with the same label as the holotype, one male with an additional green text label “7281” ( MZB, KSP) .

Description.

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. 2 ).

Colouration: Dorsally piceous, with paler lateral sides of pronotum (Fig. 2 ). Head piceous, with slightly paler, dark brown, anterior margin; pronotum piceous, slightly paler towards lateral sides, lateral sides brown to dark brown, yellowish red to reddish brown at anterior angles; elytra uniformly piceous or with dark brown sutural lines; head appendages and proximal part of legs yellowish brown, legs distally brown.

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. 2 ). Pro- and mesotarsomeres 1-3 not dilated, relatively narrow. Protarsomere 4 cylindrical, narrow, with medium-sized, long, relatively slender, strongly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of 14 and posterior row of five short setae (Fig. 6A ). Median lobe with distinctly discontinuous outline; in lateral view, almost straight, with large, evenly tapering and curved downwards apex; in ventral view, with weak submedian constriction, distal part distinctly narrower than proximal one, apex truncate (Fig. 6B, C ). Paramere with strong notch on dorsal side and subdistal part subquadrate, large and broad; subdistal setae long, dense, thick, and flattened; proximal setae hair-like, numerous, more inconspicuous than subdistal ones (Fig. 6D ). Abdominal ventrite 6 distinctly concave, with 9-11 lateral striae on each side.

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

Affinities.

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 Shaverdo et. al., 2012 in general appearance, apically concave abdominal ventrite 6, and structure of the male genitalia, but differs from in more slender male antennae and shape of the median lobe and paramere.

Distribution.

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

Habitat.

The specimens were collected from shaded waterholes on a riverbank.

Etymology.

The species is named after Waaf Village. 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.