Austrelatus rugosus, 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

25. Austrelatus rugosus sp. nov.

Figs 75 , 79 , 84 , 87 , 90

Type locality.

Indonesia: Indonesia: Papua Province: Puncak Regency, Iratoi, near Rouaffer River, 03°14'25.1"S, 137°19'58.7"E, 164 m a.s.l.

Type material.

Holotype: male "Indonesia: Papua, Rouaffer, Iratoi, hill in forest, 164 m, 6.ix.2014, -3,2403 137,3329, Sumoked (PAP028)" (MZB).

Paratypes: IN: Papua: Puncak Regency: 8 males, 9 females, with the same label as the holotype, two males with green text additional labels “6473”, “6474” (KSP, MZB, NHMW, ZSM).

Nabire Regency: 8 males, 8 females "Irian Jaya: Paniai Prov. road Nabire - Ilaga, km 65, 29.8.1996, 250 m (96 # 6)" (NHMW, ZSM). 3 males "West New Guinea/Paniai Prov./IR 22 track Nabire-Ilaga km 62 250 m, 24.7.1991, forest pools leg: Balke & Hendrich" (CLH, ZSM). 1 female "West New Guinea/Paniai Prov./IR 18 River n. Nabire, 2 m, 15.7.1991 leg: Balke & Hendrich leg." (CLH). 1 female "West New Guinea/Paniai Prov./IR 19 track Nabire-Ilaga km 54 Basecamp, 750-800 m, 16.-27.7.1991 leg: Balke & Hendrich" (ZSM). 1 male "Irian Jaya: Paniai Prov. road Nabire - Ilaga, km 54, 10.9.1996, 900 m (96 # 19)" (NHMW).

West Papua: Kaimana Regency: 1 male, 2 females "Irian Jaya: Fak Fak dist. Lake Yamur area, IV.1998 ca. 50 - 100 m, Waldtümpel, Konyorah" (NHMW).

Teluk Wondama Regency: 6 males "Irian Jaya: Wandammen Bay, Wasior, Sararti 100-200 m, 7-9.I.2001 leg. A. Riedel" (SMNS).

Description.

Body size and form: Beetle small, with oblong-oval habitus (Fig. 75 ).

Measurements: TL 4.15-4.7 mm, TL-H 3.8-4.25 mm, MW 2-2.3 mm, TL/MW 2.04-2.08; PL 0.6-0.7 mm, PW 1.75-2 mm, PL/PW 0.34-0.35; DBE 0.75-0.8 mm, DBE/PW 0.4-0.42.

Holotype: TL 4.65 mm, TL-H 4.2 mm, MW 2.25 mm, TL/MW 2.07; PL 0.65 mm, PW 1.9 mm, PL/PW 0.34; DBE 0.8 mm, DBE/PW 0.42.

Colouration: Dorsally reddish brown to dark brown, with reddish head and pronotum, elytron with yellow-red to dark brown basal band or spots and vague spot on apex (Fig. 75 ).

Head yellowish red to reddish brown, sometimes darker narrowly behind eyes. Pronotum yellowish red to reddish brown, paler on sides, often darker at anterior and posterior margins. Elytron reddish brown to dark brown, sometimes concolourous with head and pronotum, with yellowish red to reddish brown basal band at its middle due to confluence of two spots; one of spots normally larger, therefore band with notched posterior margin; sometimes band can be extended to suture due to presence of one more spot; seldom spots not confluent, distinct; band can be very distinct or very vague so that elytron seems to be uniformly coloured or slightly paler basally; elytron with distinct or vague, rather small, 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 and abdominal ventrites 1-3.

Surface sculpture: Elytron with 11 distinct, complete dorsal striae; submarginal stria present: 11+1. Dorsal surface with tiny strioles (Fig. 75 ).

Head with few strioles only between eyes or medially, with rather sparse punctation (spaces between punctures 1-4 × size of punctures); punctures relatively small (diameter of punctures equal to or slightly smaller 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 numerous, dense or rather sparse, strioles in whole surface, seldom only laterally and posteriorly, without longitudinal wrinkles; 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 distinct. Elytron with 11 complete, strongly or less strongly impressed dorsal striae; odd striae shortly reduced apically; submarginal stria present, very long, almost reaching elytral base. Elytron with fine or rather distinct punctation and distinct microreticulation; additionally, to distinct punctures, tiny strioles can be present, especially in females. Ventral part with fine, inconspicuous punctation, slightly visible on metaventrite and metacoxae and stronger on abdominal ventrites; prosternum smooth medially; metaventrite and metacoxae with fine microreticulation medially; on abdominal ventrites microreticulation almost invisible; metacoxal plates with short, numerous, rather sparse, 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 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 long basal crest; apex of left dorsal lobe relatively short and slightly curved downwards; its dorsal surface without denticulation, but with a strong median crest visible in left lateral view; right dorsal lobe with well-developed, more laterally 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, equal, straight apically; sclerotised part of left ventral lobe long, thin, and straight apically, more than 2/3 of length of left dorsal lobe. Paramere with setae not clearly divided into distal and proximal; more distally situated setae usually denser than more proximal ones (Fig. 79 ).

Female: There are females without evident differences from males in surface sculpture; there are some with coarser and denser dorsal punctation and more strongly impressed reticulation (in Iratoi, Wasior and Fakfak); there are specimens with numerous, dense, tiny elytral strioles (in Nabire Province). However, there are no strongly striolated, matt forms.

Variability.

There is a strong variation in the colouration and dorsal striolation described above. For the specimens from the type locality (96 # 6, road Nabire-Enarotali), more elongate body shape, paler dorsal colouration (when elytron almost concolourous with head and pronotum), more weakly impressed elytral striae, and presence of tiny elytral strioles instead of punctures (especially in females) are characteristic. The specimens from Iratoi, Wasior, and Fakfak are more oval, darker, with more strongly impressed elytral striae, and without tiny elytral strioles. Shape of the median lobe constant, with an insignificant variation in sclerite shape.

Affinities.

Based on shape of the median lobe (especially shape of the sclerotised part of left ventral lobe), pronotal and elytral striation, and in some measure dorsal colouration, the species is close to A. vagauensis sp. nov. but distinctly differs from it in much smaller body size and straighter median lobe sclerites. The species is also very similar to A. debulensis sp. nov. in dorsal colouration and striation and especially in shape of median lobe. However, we consider it as a separate species because of more strongly developed dorsal striolation, shorter and more strongly curved downwards apical part of left dorsal lobe and more laterally situated median impression of the right ventral lobe.

Etymology.

The species name is a Latin adjective meaning rugose, wrinkled, to describe a distinct striolation of the pronotum and elytra in both sexes.

Distribution.

New Guinean endemic. Indonesia: West Papua Province: Kaimana and Teluk Wondama regencies and Papua Province: Nabire and Puncak regencies (Fig. 84 ).

Habitat.

At the type locality, the species was collected in a large forest stream (Fig. 90 ). At the Nabire-Ilaga track, all specimens were collected in shallow (up to 20 cm water depth), shaded or at least partly shaded forest pools (e.g., Fig. 87 ) and puddles of different size, rich in rotten leaves and twigs; few specimens were also found in water-filled track hollows on forest tracks.

Figures

Figure 79. Austrelatus rugosus 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 87, 88. Habitats of Austrelatus species 87 small forest pool at track Nabire-Ilaga, Km 62: type localities of A. innominatus sp. nov. and A. pseudooksibilensis sp. nov. and habitats of A. febrisauri sp. nov., A. rugosus sp. nov., and A. kaszabi (Guignot, 1956) 88 partly shaded rest pool of an intermittent stream at the road Wanggar to Bali Bumi: type locality of A. wanggarensis sp. nov. Photographs by LH.

Figures 89, 90. Habitats of Austrelatus species, Indonesia: Papua 89 Foja Mts, bog in rainforest, (PAP 058): type locality of A. fojaensis sp. nov. 90 Rouaffer, Iratoi, forest stream, (PAP 028): type locality of A. setiphallus sp. nov., A. rugosus sp. nov. and A. rouaffer sp. nov. and habitat of A. kaszabi (Guignot, 1956). Photographs by MB.