Austrelatus vagauensis, 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

31. Austrelatus vagauensis sp. nov.

Figs 68 , 72 , 84

Type locality.

Papua New Guinea: Morobe Province, Herzog Mts, Vagau, ca. 1200 m a.s.l.

Type material.

Holotype: male "Stn. No. 144.", "New Guinea: Morobe Dist., Herzog Mts., Vagau, C.4,000 ft. 4-17.i.1965", "M.E. Bacchus. B.M. 1965-120" (BMNH).

Paratypes: PNG: Morobe: 3 males, 6 females with the same label as the holotype (BMNH, NHMW). 2 males, 2 females "June 23, 1988 Papua New Guinea Morobe, Lake Trist MP Kowalski", "Loc. 7.9 S, 146.96 E Elev. 1710 m Pandanus swamp NW edge of Lake Trist" (CMPK, NHMW).

Description.

Body size and form: Beetle medium-sized to large, with oblong-oval habitus (Fig. 68 ).

Measurements: TL 6.1-7 mm, TL-H 5.5-6.25 mm, MW 2.9-3.35 mm, TL/MW 2-2.1; PL 0.85-1 mm, PW 2.5-2.9 mm, PL/PW 0.33-0.35; DBE 1-1.1 mm, DBE/PW 0.38-0.41.

Holotype: TL 6.4 mm, TL-H 5.85 mm, MW 3.1 mm, TL/MW 2.07; PL 0.9 mm, PW 2.7 mm, PL/PW 0.33; DBE 1.05 mm, DBE/PW 0.39.

Colouration: Dorsally piceous, with yellowish red head medially, pronotal sides and three small basal spots and one apical spot on elytron (Fig. 68 ).

Head yellowish red, dark brown behind eyes and reddish brown anteriorly, often also reddish brown medially, so that head has a broad, yellowish red V-like pattern or a reddish brown, median spot. Pronotum piceous on disc and paler towards sides, broadly yellowish red on them. Elytron piceous, with three rather distinct, small, yellowish red spots on elytral base: one between striae 1 and 3, second between striae 5 and 7 and third between striae 9 and 10; these spots never confluent; elytron with a distinct, narrow, yellow lateral band ending up with a slightly broader elongate apical spot. Scutellum yellowish red. Antennae, other head appendages, and legs proximally yellowish red; legs darker distally, yellowish red, especially metalegs. Venter piceous, with paler prosternum. Teneral beetles paler. The holotype is teneral specimen.

Surface sculpture: Elytron with 11 dorsal strongly impressed striae; submarginal stria present: 11+1 (Fig. 68 ).

Head with strioles between eyes, with rather dense punctation (spaces between punctures 1-3 × times size of punctures); punctures relatively fine (diameter of punctures equal to diameter of microreticulation cells or smaller than it); head with a row of coarse 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; microreticulation weak. Pronotum with numerous strioles; pronotal punctation finer and denser than on head; setigerous punctures form a row along pronotal margins, absent in posterior middle; disc of pronotum with indistinct longitudinal median scratch. Pronotum with fine microreticulation. Elytron with 11 strongly impressed dorsal striae; stria 5 shortly reduced basally; striae 1, 3, 5, 7, and 9 shortly reduced apically; submarginal striae present, long, well-developed, reaching ½ or more of elytron. Elytron with fine punctation and microreticulation. Ventral part with fine, inconspicuous punctation, invisible on metaventrite and metacoxae and weak on abdominal ventrites; prosternum smooth medially; metaventrite and metacoxae with weak microreticulation; on abdominal ventrites microreticulation almost invisible; metacoxal plates with numerous, strongly 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, rugose 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 rather small, short, rounded, convex in middle, with protruding apex.

Male: Protibia almost straight, not modified. Proclaws rather long, subequal in length; anterior more strongly curved than posterior one. Median lobe of aedeagus with two lobes of dorsal sclerite rather narrow; left dorsal lobe distinctly shorter that right one, with small apical crest; apex of left dorsal lobe curved downwards and to left, its very tip upwards; dorsally and laterally with denticulation (spinulae) visible in lateral left view; right dorsal lobe with distinct, but shallow, elongate median impression and an weak angular convexity above it; apex of right dorsal lobe large, swollen, rounded; left lobe of ventral sclerite with its sclerotised area long, thin, narrowly pointed apically, shorter than right ventral and dorsal lobes and 4/5 of length of left dorsal lobe. Paramere with setae not clearly divided into distal and proximal; more distally situated setae longer and slightly denser than more proximal ones; with several, short, thin the most proximal setae standing separately (Fig. 72 ).

Female: With more numerous pronotal strioles and elytron with denser punctation and additionally to it with very tiny strioles between striae. However, there are no strongly striolated, matt forms.

Variability.

There is a insignificant variation in the body size, colouration and dorsal striolation.

Affinities.

In body shape, elytral striation and dorsal colouration, the species is similar to A. garainensis sp. nov. and A. kaszabi . The species can be distinguished from them by shape of its median lobe sclerites, especially by the weaker sclerotised area of the left ventral lobe, with its apex not curved like a hook but straight. See also under A. sarmiensis sp. nov.

Etymology.

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

Distribution.

New Guinean endemic. Papua New Guinea: Morobe Province (Fig. 84 ).

Habitat.

Lentic. Northwest of Lake Trist, the species was collected in a Pandanus swamp, where it was obtained from smaller puddles and pools rich in rotten debris.

Figures

Figure 72. Austrelatus vagauensis 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 66 - 69. Habitus and colouration of 66 Austrelatus rouaffer sp. nov. 67 A. wanggarensis sp. nov. 68 A. vagauensis sp. nov. 69 A. sandaunensis sp. nov.