Austrelatus rajaampatensis, 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

23. Austrelatus rajaampatensis sp. nov.

Figs 54 , 55 , 57 , 84

Type locality.

Indonesia: Papua Province: Raja Ampat Regency, northern Batanta, 00°50.125'S, 130°42.856'E, 20 m a.s.l.

Type material.

Holotype: male "Indonesia: Papua, Batanta Utara, 20 m, 14.ii.2006, 00.50.125S 130.42.856E, Tindige et al. (BH 12)" (MZB).

Paratypes: IN: West Papua: Raja Ampat Regency: Batanta: 34 males, 6 females with the same label as the holotype (MZB, NHMW, ZSM). For additional paratypes see Appendix 1.

Description.

Body size and form: Beetle small to medium-sized, with oblong-oval habitus (Figs 54 , 55 ).

Measurements: TL 4.4-5.6 mm, TL-H 3.9-5.1 mm, MW 2.1-2.65 mm, TL/MW 2-2.11; PL 0.65-0.85 mm, PW 1.85-2.3 mm, PL/PW 0.35-0.37; DBE 0.8-0.95 mm, DBE/PW 0.41-0.43.

Holotype: TL 5 mm, TL-H 4.55 mm, MW 2.5 mm, TL/MW 2; PL 0.75 mm, PW 2.15 mm, PL/PW 0.35; DBE 0.9 mm, DBE/PW 0.42.

Colouration: Dorsally piceous, with yellowish red head, pronotal sides, and basal band and apical spot on elytron (Figs 54 , 55 ).

Head yellowish red to reddish brown, darker narrowly behind eyes. Pronotum brown to piceous, paler towards sides, yellowish red to reddish brown on them. Elytron piceous, with yellow to reddish brown basal band starting at striae 1-3 and not reaching suture and lateral margin; with slightly to distinctly notched posterior margin; elytron with distinct, elongate spot apically. Scutellum yellowish red to piceous. Antennae and other head appendages yellow. Pro- and mesolegs yellow and metalegs yellowish red proximally and darker distally. Venter mostly yellowish red, with to yellow base of prosternum and abdominal ventrites 1-3, abdominal ventrites 4-6 yellowish red medially and paler laterally.

Surface sculpture: Elytron with 10-11 dorsal striae, complete or interrupted and reduced; submarginal stria present or absent: (10-11)+(0-1) (Figs 54 , 55 ).

Head without strioles, with rather dense punctation (spaces between punctures 1-3 × size of punctures); punctures relatively small (diameter of punctures equal to 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 sparse strioles in whole surface or with only few at posterior margin or posterior angles; with or without longitudinal wrinkles at posterior margin; pronotal punctation finer 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. Elytron usually with 11 dorsal striae; striae weakly to strongly impressed; odd striae shortly reduced apically; stria 1 or striae 1-3 shortly reduced basally; sometimes stronger stria reduction can take place: stria 1 reduced completely, elytron with only ten reduced and interrupted striae; submarginal stria present, well-developed, sometimes reaching ½ of elytron; in specimens with reduced stria pattern, absent or weak, short, apical. Elytron with fine punctation and microreticulation. 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; 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 long, 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 long lateral crest and apex curved downwards; its dorsal surface with weak denticulation usually visible in left lateral view; right dorsal lobe with distinct median impression in right lateral view and with very “swollen”, rounded, pea-like apex. Lobes of ventral sclerite weakly sclerotised laterally, visible in left and right lateral views, mostly membranous, subequal, straight apically; sclerotised part of left ventral lobe long and straight apically, approximately 1/2 length of left dorsal lobe. Paramere with setae not clearly divided into distal and proximal; more distally situated setae distinctly denser than more proximal ones (Fig. 57 ).

Female: As male.

Variability.

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

Affinities.

The species is similar to A. moreguinensis sp. nov., their comparison see under this species.

Etymology.

The species is named after Raja Ampat Regency where it is widely distributed. The name is an adjective in the nominative singular.

Distribution.

New Guinean endemic. Indonesia: Papua Province: Raja Ampat and Sorong regencies (Fig. 84 ).

Habitat.

Unknown.

Figures

Figure 57. Austrelatus rajaampatensis 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.