Austrelatus innominatus, 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

10. Austrelatus innominatus sp. nov.

Figs 52 , 53 , 56 , 84 , 87

Type locality.

Indonesia: Papua Province, Nabire Regency, road Nabire - Ilaga, 62nd km, 250 m a.s.l.

Type material.

Holotype: male "West New Guinea/Paniai Prov./IR 22 track Nabire-Ilaga km 62 250 m, 24.7.1991, forest pools leg: Balke & Hendrich" (ZSM).

Paratypes: IN: Papua: Nabire Regency: 7 males, 16 females with the same label as the holotype (CLH, MZB, NHMW, ZSM). Additional paratypes see in the Appendix 1.

Description.

Body size and form: Beetle small or medium-sized, with oblong-oval to elongate habitus (Figs 52 , 53 ).

Measurements: TL 4.7-5.6 mm, TL-H 4.2-4.95 mm, MW 2.3-2.6 mm, TL/MW 2-2.07; PL 0.65-0.8 mm, PW 1.9-2.3 mm, PL/PW 0.34-0.36; DBE 0.8-0.95 mm, DBE/PW 0.4-0.42.

Holotype: TL 5.2 mm, TL-H 4.65 mm, MW 2.6 mm, TL/MW 2; PL 0.8 mm, PW 2.25 mm, PL/PW 0.36; DBE 0.9 mm, DBE/PW 0.4.

Colouration: Dorsally piceous, with yellowish red head, narrow pronotal sides and a broad basal band and one apical spot on elytron (Figs 52 , 53 ).

Head yellowish red to reddish brown, darker narrowly behind eyes. Pronotum brown to piceous, narrowly yellowish red on sides or only at anterior angles. Elytron piceous, with a distinct yellow to reddish brown basal band, with notched posterior margin, not reaching lateral margin and suture; elytron with distinct elongate apical spot. Scutellum reddish brown to piceous. Antennae, other head appendages, and pro- and mesolegs proximally yellowish red, metalegs red, legs darker distally. Venter reddish brown. Teneral beetles paler.

Surface sculpture: Elytron usually with 10-11 complete dorsal striae, seldom with 6 complete and 4 reduced and interrupted striae; submarginal stria present: (10-11)+1 (Figs 52 , 53 ).

Head without strioles, with rather dense punctation (spaces between punctures 1-3 × size of punctures); punctures relatively coarse (diameter of punctures equal to diameter of microreticulation cells or larger 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 strong. Pronotum with strioles in posterolateral parts; with fine longitudinal wrinkles at posterior margin; pronotal punctation finer 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 usually with 11 complete dorsal striae, striae weakly impressed, especially striae 1-3; stria 1 has tendency to reduction, it often completely or partly reduced or interrupted, especially basally; striae 5, 7, 9 and 10 sometimes interrupted basally; maximal stria reduction to 6 complete and 4 reduced to strioles striae. 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, weakly 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 broadly rounded anteriorly, convex medially; blade of prosternal process narrow, convex in middle.

Male: Protibia almost straight, not modified. Proclaws relatively short, subequal in length; anterior claw slightly more strongly curved downwards than posterior. Median lobe of aedeagus with two lobes of dorsal sclerite rather narrow; left dorsal lobe distinctly shorter that right one, with a lateral crest interrupted into apical and basal parts; apex of left dorsal lobe distinctly curved downwards, dorsally with denticulation (spinulae) invisible in lateral left view due to strong curvature downwards; right dorsal lobe with small, indistinct, elongate median impression and modified apex: swollen, rounded; left lobe of ventral sclerite with its sclerotised area rather large, broad, slightly concave, rounded apically, shorter than right ventral and dorsal lobes and slightly more than 1/2 length of left dorsal lobe. Paramere with setae not clearly divided into distal and proximal; with few, thin the most proximal setae standing separately (Fig. 56 ).

Female: With more strongly striolated pronotum and more distinct dorsal punctation. There are no striolated, matt forms.

Variability.

There is a variation in the colouration and dorsal striolation described above. In addition, there is one specimen (locality 96#12) with strong reduction of elytral striae to 6 complete striae only, however, it shows the same dorsal colouration and shape of the male proclaws and median lobe sclerites as the other specimens of A. innominatus .

Affinities.

In general shape of median lobe, especially in shape of the sclerotised area of left ventral lobe and in shape of the lateral crest of the left dorsal lobe, the species is similar to A. fojaensis sp. nov. and A. rouaffer sp. nov. The species can be distinguished from them by its dorsal striolation, colouration, and median lobe sclerites.

Etymology.

The species name is Latin adjective and means “unnamed” because of the long and unsuccessful attempt to find a name for this species. The name is an adjective in the nominative singular.

Distribution.

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

Habitat.

At the type locality, the species was collected in a small forest pool (Fig. 87 ). At the Nabire-Ilaga track, all other specimens were collected in similar habitats: in shallow (up to 20 cm water depth), shaded or at least partly shaded forest pools 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 56. Austrelatus innominatus 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 52 - 55. Habitus and colouration of 52 Austrelatus innominatus sp. nov., with reduced elytral striae 53 A. innominatus sp. nov., with complete elytral striae 54 A. rajaampatensis sp. nov., with reduced elytral striae 55 A. rajaampatensis sp. nov., with complete elytral striae.

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.