Austrelatus nadjae, 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

18. Austrelatus nadjae sp. nov.

Figs 16 , 20 , 82 , 91-92 , 93

Type locality.

Indonesia: Papua Province: Puncak Regency, south from Iratoi, 03°21'08.3"S, 137°17'42.1"E, 161 m a.s.l.

Type material.

Holotype: male "Indonesia: Papua, S Iratoi, river camp, 161 m, 20./25.v.2015, -3,3522 137,2950, Sumoked (PAP035)" (MZB).

Paratypes: IN: Papua: Puncak Regency: 21 males, 11 females with the same label as the holotype (MZB, KSP, NHMW, ZSM). 1 male "Indonesia: Papua, S Iratoi, hunting camp, 150 m, 28.v.2015, -3,2801 137,3341, Sumoked (PAP042)", “7232” [green text] (KSP, MZB, ZSM).

Yahukimo Regency: 2 males, 1 female "Indonesia: Papua, Dekai, upper Brazza, 273 m, 2/3.vi.2015, -4,7410 139,6542, Sumoked (PAP044)", “7210”, “7211”, “7212” [green text], respectively (ZSM).

Description.

Body size and form: Beetle small, with oval habitus (Fig. 16 ).

Measurements: TL 4.8-5.1 mm, TL-H 4.4-4.7 mm, MW 2.55-2.8 mm, TL/MW 1.82-1.88; PL 0.7-0.8 mm, PW 2.1-2.4 mm, PL/PW 0.33-0.34; DBE 0.9-1 mm, DBE/PW 0.41-0.43.

Holotype: TL 4.9 mm, TL-H 4.45 mm, MW 2.6 mm, TL/MW 1.88; PL 0.75 mm, PW 2.2 mm, PL/PW 0.34; DBE 0.9 mm, DBE/PW 0.41.

Colouration: Dorsally piceous, with reddish yellow head, pronotal sides, elytral basal band and elytral apicolateral band (Fig. 16 ).

Head reddish yellow, dark brown behind eyes, sometimes vaguely brown medially and posteriorly. Pronotum dark brown to piceous, slightly paler anteriorly and laterally, with reddish yellow sides. Elytron piceous, slightly paler on disc and darker laterally, with reddish yellow basal band of different length but not reaching suture and lateral elytral margin; its anterior margin reaching elytron basally and its posterior margin strongly notched: with three distinct prolongations between puncture rows, longest near suture; elytron with distinct, reddish yellow, elongate apical spot continuing laterally as a thin band till middle of elytra or slightly further. Scutellum reddish yellow to piceous. Antennae and other head appendages yellowish brown. Pro- and mesolegs yellowish brown proximally and darker distally, especially metalegs. Venter brown to piceous, with paler prosternum. Teneral beetles paler.

Surface sculpture: Elytron without striae: 0+0, but with distinct puncture lines (Fig. 16 ).

Head without strioles, with relatively dense, even punctation (spaces between punctures 1-3 × size of punctures); punctures relatively large (diameter of punctures more or less equal to diameter of cells of microreticulation) but not coarse; head with a row of coarse setigerous punctures along inner margin of each eye and a very short row of much weaker punctures at frontal angle of each eye; a slightly longer puncture row forms fronto-clypeal depression at each head side; head with strong microreticulation. Pronotum usually with distinct strioles at posterior angles that sometimes very few and inconspicuous, with short, thin, rather inconspicuous longitudinal wrinkles at middle of posterior margin; pronotal punctation slightly finer than on head; coarse setigerous punctures form a broad row along pronotal margins, absent in posterior middle; disc of pronotum with indistinct short, thin, longitudinal median scratch. Pronotal microreticulation rather weakly impressed on disc. Elytron without elytral striae but with two distinct puncture lines on disc and one laterally, some of their coarse punctures contiguous, especially those of discal lines; two additional lines of very sparse, coarse setigerous punctures can be seen between elytral lines; elytron with distinct, especially more laterally, rather dense punctation; microreticulation weak. Ventral part with extremely fine, scarce, inconspicuous punctation, invisible on metaventrite and metacoxae and more distinct on abdominal ventrites; prosternum smooth medially; metaventrite and metacoxae with weak microreticulation; on abdominal ventrites microreticulation almost invisible; metacoxal plates with more or less short 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 distinct punctation that sparser medially and forms a very dense lateral area at each side.

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

Male: Protibia straight, not modified. Proclaws short, subequal in length: anterior claw very slightly shorter than posterior one. Median lobe of aedeagus with two lobes of dorsal sclerite narrow; right dorsal lobe longer than left one; in lateral view, apex of left dorsal lobe slightly curved downwards; left dorsal lobe dorsally relatively broad, with fine but distinct denticulation (spinulae) slightly visible also in lateral left view; right dorsal lobe with large median impression (in right lateral view) and modified apex: swollen, very broadly rounded but with its outer margin more or less straight. Left lobe of ventral sclerite with its sclerotised area weakly visible laterally, distinctly shorter than right ventral lobe; its apex more or less rounded, not hooked. Paramere with setae not divided into distal and proximal; more distally situated setae denser and slightly longer than more proximal ones (Fig. 20 ).

Female: With stronger surface sculpture than males and very variable in it. They have many more strioles on pronotum, sometimes absent only on disc. Strioles can be present with different intensity on elytra, usually more numerous laterally. In rare cases (three specimens), there are completely striolated, matt forms. One female demonstrates development of the elytral puncture lines (especially discal) into weakly impressed striae.

Affinities.

In absence of the elytral striae and general shape of the median lobe, it is similar to A. lembenensis sp. nov., but differs from it distinctly more oval habitus, more prominent yellow pattern and different shape of the median lobe. The species is extremely similar and most likely related to broadly distributed A. mirificus sp. nov. We treat it here as a separate species because of absence of the elytral striae, less intensive yellow colouration, differences in female dorsal striolation (see under “Female” for both species) and in shape of the median lobe, for details see under A. mirificus sp. nov.

Etymology.

The species is named after Nadja, the elder daughter of H. Shaverdo. "You are beautiful and great as you are!" The species name is a noun in the genitive case.

Distribution.

New Guinean endemic. Indonesia: Papua Province: Puncak and Yahukimo regencies (Fig. 82 ).

Habitat.

At the locality PAP044, it was collected in puddles or pools among rotten leaves and twigs (Figs 91 , 92 ); at the locality PAP042 in a forest pool (Fig. 93 ).

Figures

Figure 20. Austrelatus nadjae 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 82. Map of New Guinea showing distribution of 11 Austrelatus species.

Figure 93. Habitat of Austrelatus species, Indonesia: Papua, S Iratoi, forest pool, (PAP 042): type locality of A. securiformis sp. nov. and habitat of A. rouaffer sp. nov. and A. nadjae sp. nov. Photograph by MB.

Figures 14 - 17. Habitus and colouration of 14 Austrelatus adelbert (Megna et al., 2017) 15 A. lembenensis sp. nov. 16 A. nadjae sp. nov. 17 A. pseudoneoguineensis 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.