Austrelatus clarki (Sharp, 1882) 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

Austrelatus clarki (Sharp, 1882) comb. nov.

Figs 8 , 13

Copelatus clarki Sharp 1882: 585; Hendrich et al. (2019: 89); Larson (1993: 52, 1997: 276); Watts (1978: 125, 1985: 26, 2002: 42); Nilsson and Hájek (2023: 47).

Copelatus vagestriatus Zimmermann 1919: 199; syn. nov.

Type localities.

Copelatus clarki : "Australia (Cape York)"; C. vagestriatus : “Neuguinea”.

Type material.

Copelatus clarki . Lectotype (designated by Watts 1978: 125): male, “Lectotype” [round label with violet frame], “Type” [round printed label with red frame], "Cape York. 676" [hw label], "Sharp Coll. 1905-313." [printed label], "Type to 76 Copelatus clarki n.sp. Cape Yorke" [hw label], " Copelatus clarki Sharp Det. C. Watts det. 1971" [hw label] (BMNH).

Paralectotype: female, “Paralectotype” [round label with blue frame], “Cotype” [roundish label with yellow frame], "Cape York. 676" [hw label], "Sharp Coll. 1905-313." [printed label], " Copelatus clarki Cap York" [hw label], " Copelatus clarki Sharp Det. C. Watts det. 1971" [hw label] (BMNH).

Copelatus vagestriatus . Holotype: female “NeuGuinea”, "Coll. Kraatz", “TYPUS” [red label], " Copelatus vagestriatus Rég. N. sp. typ." [hw], “Holotypus” [red label] (SDEI).

Additional material studied.

PNG: Morobe Province, first record: 1 male, 1 female "Stn. No. 103.", "NEW GUINEA: Morobe Dist., Finisterre Mts., Mt. Abilala , c. 9,000 ft. 19-22.xi.1964.", " M.E. Bacchus. B.M. 1965-120", for male "measured J. Parkin 21" and for female "measured J. Parkin 22" (BMNH) .

National Capital District, first record: 2 males, 1 female "Stn. No. 202.", "PAPUA: Musgrave River, Sogeri Plateau, Nr. Pt. Moresby , 16.iii.1965 ", " M.E. Bacchus. B.M. 1965-120" (BMNH) . 1 male "Stn. No. 206.", "PAPUA: Loloki c. 10 m. N. of Pt. Moresby. 19.iii.1965 ", " M.E. Bacchus. B.M. 1965-120" (BMNH) . 1 male "Stn. No. 207a.", "PAPUA: Moitaka, c. 7 m. N. of Pt. Moresby. 17.iii.1965 ", " M.E. Bacchus. B.M. 1965-120" (BMNH) .

Diagnosis.

Beetle large: TL 7.2-8.0 mm, TL-H 6.5-7.2 mm, with oblong-oval habitus. Dorsal colouration piceous, with reddish brown head and pronotal sides, sometimes also elytron basally. Elytron with (3-8)+(0-1) striae, and no striae or only apical traces of two additional striae inwards from first row of serial punctures. Median lobe of aedeagus with dorsal and ventral sclerites distinctly separated medially forming a median hole; dorsal and ventral sclerites each divided into two lobes in apical half; lobes of dorsal sclerite unequally developed: left lobe reduced, small, with pointed apex, closely pressed to enlarged right lobe; apex of right lobe broadly rounded; left lobe of dorsal sclerite without distinct surface sculpture, smooth. Paramere with setae divided into distal and proximal; proximal setae slightly shorter and sparser than distal ones.

For the detailed morphological description, illustrations, NG material and data on its distribution and habitat, see Hendrich et al. 2019: 89-95, 126, 127, 129, 137, 143.

Description of holotype of Copelatus vagestriatus .

Body size and form: Beetle large, with oblong-oval habitus (Fig. 8B ).

Measurements: TL 6.8 mm, TL-H 6.4 mm, MW 3.4 mm, TL/MW 2; PL 0.95 mm, PW 2.85 mm, PL/PW 0.33; DBE 1 mm, DBE/PW 0.35.

Colouration: Dorsally dark brown, with yellowish red head, pronotal sites and vague reddish basal band on elytron (Fig. 8B ).

Head yellowish red, dark brown behind. Pronotum dark brown, paler laterally, with yellowish red lateral sites, yellowish at anterior angles. Elytron dark brown, with vague reddish basal band and reddish lines along suture. Scutellum reddish brown. Antennae and other head appendages yellow to dark yellow. Pro- and mesolegs yellow proximally and yellowish brown distally, metalegs darker. Venter dark brown, with reddish brown prosternum and abdominal ventrites.

Surface sculpture: Dorsally with 5 uncomplete elytral dorsal striae, submarginal stria absent: 5+0 (Fig. 8B ).

Head without strioles, with relatively sparse, weakly impressed punctation (spaces between punctures 2-4 × size of punctures); punctures relatively large (diameter of punctures equal to diameter of cells of microreticulation); head with a small uneven median depression probably due to some coarser punctures at each side; a row of coarse setigerous punctures along inner eye margin present; a very short row of such punctures present at frontal angle of each eye and a longer puncture row forms fronto-clypeal depression at each head side; head with strong microreticulation. Pronotum with inconspicuous, fine strioles at posterior angles and weak longitudinal wrinkles in middle, at posterior margin; pronotal punctation finer, denser, more distinct than on head; coarse setigerous punctures form a row along anterior margin and in lateral and basolateral depressions; some coarse setigerous punctures also evident along lateral parts of posterior margin; disc of pronotum with a long, thin, longitudinal median scratch. Pronotal microreticulation distinct. Elytron with 5 uncomplete elytral dorsal striae: stria 1 the most complete one but present as row of dense punctures and strioles, stria 2 the most reduced one, present as row of sparse punctures and strioles, striae 3 and 5 present subapically as striae and basally and apically from this part as rows of dense punctures and strioles, stria 4 completely reduced in basal part and present subapically as stria; submarginal stria absent; elytral punctation fine, dense, distinct; microreticulation distinct. Ventral part with very fine, scarce, inconspicuous punctation, invisible on metaventrite and metacoxae and more distinct on abdominal ventrites, especially laterally on abdominal ventrite 6; prosternum smooth medially; metaventrite and metacoxae with distinct microreticulation, weaker medially; abdominal ventrites with weakly impressed microreticulation; metacoxal plates with numerous longitudinal strioles, abdominal ventrites 1 and 2 with numerous, long, longitudinal strioles from margin to margin, on abdominal ventrites 3-5 strioles situated laterally and turn to middle, almost horizontal, abdominal ventrite 6 without strioles.

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 rather small and narrow, distinctly convex.

Female genitalia: Gonocoxosternum of usual Copelatinae shape; gonocoxa long, slender, with distinctly obliquely truncated apex.

Variability.

There is a variability in the colouration and elytral striation among and within the populations. Although majority of Australian and New Guinea specimens have piceous dorsal colouration, with reddish brown head and pronotal sides, some specimens from the same populations show presence of a vague or rather distinct, reddish or yellowish red elytral basal band. It is characteristic for all known New Guinean populations. Whilst Australian and majority of New Guinean specimens have seven or eight dorsal elytral striae and no striae or only apical traces two additional striae inwards from the first row of serial punctures, some New Guinean representatives have a stronger reduction of the striae. For example, the holotype of C. vagestriatus has only five dorsal striae and no submarginal stria on the elytron. An extreme reduction of the elytral striae is observed in some specimens from the Port Moresby localities: three or four uncomplete dorsal striae, sometimes present only as rows of dense punctures and strioles, submarginal stria absent.

Comments to classification.

Since the holotype of C. vagestriatus is a female, it was difficult to decide about its taxonomic position. However, it was recognised as belonging to Austrelatus , not Copelatus , because of its large size and 5+0 elytral striae (see above for New Guinean Copelatus species). Our careful examination of the holotype and its comparison with all known large-sized Austrelatus allows us to assume that C. vagestriatus is in fact A. clarki with a strong reduction of the elytral striae and paler colouration. It shares with A. clarki several similarities in body size and shape, punctation and microreticulation, shape of the prosternum and female genitalia, especially shape of apexes of the gonocoxae. Its dorsal colouration and elytral striation are similar to those of the A. clarki specimens from Port Moresby localities. Therefore, though the type locality of C. vagestriatus is indicated only as New Guinea, we assume that the holotype might been collected somewhere in the National Capital District. Thus, we consider Copelatus vagestriatus Zimmermann, 1919, syn. nov. to be a junior subjective synonym of Austrelatus clarki (Sharp, 1882).

Distribution.

In NG, this generally Australian species is known from the southern and eastern parts of the island: IN: Papua Province, Merauke Regency ( Hendrich et al. 2019: 93) and PNG: Western Province ( Hendrich et al. 2019: 93), Morobe and NCD provinces (Fig. 13 ).

Habitat.

In northern Australia and near Merauke (southern PNG), most specimens were collected in various smaller pools and puddles, also in the rest pools of intermittent creeks and smaller rivers of open and eucalypt woodland, often rich in rotten leaves and twigs. The species is also attracted at light ( Hendrich et al. 2019).

Figures

Figure 13. Map of New Guinea showing distribution of Austrelatus clarki (Sharp, 1882), A. fumato sp. nov., and A. setiphallus sp. nov.

Figures 8, 9. 8 Austrelatus clarki (Sharp, 1882) A median lobe in left lateral view B habitus and colouration of holotype of Copelatus vagestriatus Zimmermann, 1919, syn. nov., female 9 Austrelatus fumato sp. nov., habitus and colouration of A holotype B specimen from Sorong.