Austrelatus debulensis, Shaverdo & Hájek & Hendrich & Surbakti & Panjaitan & Balke, 2023

Shaverdo, Helena, Hajek, Jiri, Hendrich, Lars, Surbakti, Suriani, Panjaitan, Rawati & Balke, Michael, 2023, Austrelatus gen. nov., a new genus of Australasian diving beetles (Coleoptera, Dytiscidae, Copelatinae), with the discovery of 31 new species from New Guinea, ZooKeys 1170, pp. 1-164 : 1

5. Austrelatus debulensis sp. nov.

Figs 76 , 80 , 84 , 91 , 92

Type locality.

Indonesia: Papua Province: Yahukimo Regency, NE Dekai, upper Brazza River, Debula Village, 4°44'27.9"S, 139°39'15.2"E, 273 m a.s.l.

Type material.

Holotype: male "Indonesia: Papua, Dekai, upper Brazza, 273 m, 2./3.vi.2015, -4,741084724 139,654211075976, Sumoked (Pap044)" (MZB).

Paratypes: 11 males, 10 females, with the same label as the holotype, two males with additional green text labels “7222” and “7223” (MZB, NHMW, ZSM).

Description.

Body size and form: Beetle small, with oblong-oval habitus (Fig. 76 ).

Measurements: TL 4.1-4.5 mm, TL-H 3.75-4.05 mm, MW 2-2.1 mm, TL/MW 2.05-2.14; PL 0.6-0.65 mm, PW 1.7-1.8 mm, PL/PW 0.35-0.36; DBE 0.7-0.75 mm, DBE/PW 0.41-0.42.

Holotype: TL 4.45 mm, TL-H 4 mm, MW 2.1 mm, TL/MW 2.12; PL 0.65 mm, PW 1.8 mm, PL/PW 0.36; DBE 0.75 mm, DBE/PW 0.42.

Colouration: Dorsally piceous, with reddish head and pronotum, basal band and apical spot on elytron (Fig. 76 ).

Head yellowish red to brown, seldom darker, slightly darker narrowly behind eyes. Pronotum yellowish red to reddish brown, paler on sides, sometimes darker at anterior and posterior margins, seldom with dark brown disc. Elytron dark brown to piceous, not concolourous with head and pronotum, with yellowish red to reddish brown basal band usually from stria 1 till stria 11, seldom shorter; with slightly notched posterior margin; vague so that elytron seems to be paler basally; elytron with distinct or vague, elongate spot apically. Scutellum yellowish red to brown, usually concolourous with elytra. Antennae and other head appendages yellow. Pro- and mesolegs yellow and metalegs yellowish red proximally and darker distally. Venter mostly reddish brown, with yellowish red prosternum.

Surface sculpture: Elytron with 11 complete or interrupted dorsal striae; submarginal stria present: 11+1 (Fig. 76 ).

Head without strioles, with rather dense punctation (spaces between punctures 1-3 × size of punctures); punctures relatively large (diameter of punctures equal to or slightly larger than diameter of cells of microreticulation); head with a row of setigerous punctures along inner margin of each eye and a short row at frontal angle of each eye; a slightly longer puncture row forms fronto-clypeal depression at each head side; head with relatively strong microreticulation. Pronotum with several strioles mainly posteriorly and laterally, seldom medially; with longitudinal wrinkles at posterior margin; pronotal punctation finer and sparser than on head; setigerous punctures form a broad row along pronotal margins, absent in posterior middle; disc of pronotum with thin, longitudinal median scratch. Pronotal microreticulation fine to distinct. Elytron with 11 dorsal striae; odd striae shortly reduced apically; stria 10 and sometimes stria 1 shortly reduced basally, striae 1-3, 9, 10 sometimes interrupted; submarginal stria present, weakly developed, often apical or interrupted, reaching maximally ½ of elytron. Elytron with fine punctation and microreticulation fine to distinct. Ventral part with fine, inconspicuous punctation, slightly visible on metaventrite and metacoxae and stronger on abdominal ventrites; prosternum smooth medially; metaventrite and metacoxae with distinct microreticulation; on abdominal ventrites microreticulation almost invisible; metacoxal plates with short, numerous, rather sparse, distinctly impressed longitudinal strioles, abdominal ventrites 1 and 2 with numerous, long, longitudinal strioles from margin to margin, on abdominal ventrites 3 and 4 strioles situated laterally and turn to middle, almost horizontal, abdominal ventrites 5 and 6 without strioles but with fine punctation that sparser medially and forms a dense lateral area at each side.

Structures: Head relatively broad. Pronotum short and broad; lateral margins distinctly convergent anteriorly. Base of prosternum rounded anteriorly, convex medially; blade of prosternal process relatively narrow, convex in middle.

Male: Protibia straight, not modified. Proclaws simple, relatively short, subequal. Median lobe of aedeagus with two lobes of dorsal sclerite rather narrow; left lobe distinctly shorter than right one; in lateral left view, left dorsal lobe with a lateral crest interrupted into apical and basal parts, lobe concave along rather short basal crest; apex of left dorsal lobe relatively long, more or less straight; its dorsal surface without denticulation, but with a strong median crest visible in left lateral view; right dorsal lobe with well-developed, more ventrally situated median impression in right lateral view, with broad, “swollen”, rounded apex. Lobes of ventral sclerite weakly sclerotised laterally, visible in left and right lateral views, mostly membranous, subequal (right part can be protruding), straight apically; sclerotised part of left ventral lobe long, thin, and straight apically, 2/3 of length of left dorsal lobe. Paramere with setae divided into distal and proximal; proximal setae distinctly sparser and shorter than ones distal, especially in left paramere (Fig. 80 ).

Female: Females have coarser and denser dorsal punctation and more strongly impressed microreticulation, often also with numerous, tiny elytral strioles instead of punctures. However, there are no strongly striolated matt forms.

Variability.

There is a strong variation in the colouration and dorsal striation described above.

Affinities.

The species is very similar to A. rugosus sp. nov., differential diagnosis see under that species.

Etymology.

The species is named after Debula Village. The name is an adjective in the nominative singular.

Distribution.

New Guinean endemic. Indonesia: Papua Province: Yahukimo Regency. The species is known only from the type locality area (Fig. 84 ).

Habitat.

At the type locality, it was collected in puddles or pools among rotten leaves and twigs (Figs 91 , 92 ).

Figures

Figure 80. Austrelatus debulensis sp. nov., median lobe A left lateral view B right lateral view C ventral view D left paramere in external view E right paramere in internal view. Scale bar: one unit - 0.1 mm (A-C).

Figure 84. Map of New Guinea showing distribution of 14 Austrelatus species.

Figures 74 - 77. Habitus and colouration of 74 Austrelatus sarmiensis sp. nov. 75 A. rugosus sp. nov. 76 A. debulensis sp. nov. 77 A. moreguinensis sp. nov.

Figures 91, 92. Habitat of Austrelatus species, Indonesia: Papua, Dekai, upper Brazza, puddles or pools among rotten leaves and twigs (PAP 044): type localities of A. brazza sp. nov. and A. debulensis sp. nov., and habitat of A. nadjae sp. nov. Photographs by MB.