Copelatus marginatus Sharp, 1882

Hendrich, Lars, Shaverdo, Helena, Hajek, Jiri & Balke, Michael, 2019, Taxonomic revision of Australian Copelatus Erichson, 1832 (Coleoptera, Dytiscidae, Copelatinae), ZooKeys 889, pp. 81-152 : 81

Copelatus marginatus Sharp, 1882 Figures 6 , 15 , 25

Copelatus marginatus Sharp 1882: 579 (original description); Watts 1978: 124 (description); Watts 1985: 26 (general distribution); Larson 1993: 53 (habitat description); Watts 2002: 42 (checklist); Wewalka et al. 2010: 50-51 (description, new records); Nilsson and Hájek 2019: 58 (catalogue).

Type locality.

"Australia, [Queensland], Rockhampton".

Type material.

Lectotype (designated by Watts: 1978: 124): Male, " Lectotype " [printed label with violet frame]; "Rockhampton 675." [printed label]; "Sharp Coll 1905-313." [printed label]; "Type 675 Copelatus marginatus Rockhampton" [hw label] (NHMUK). Paralectotypes: 1 male, 5 females, “Paralectotype” [printed label with blue frame]; "Rockhampton 675." [printed label]; "Sharp Coll 1905-313." [printed label]; "Type 675 Copelatus marginatus Co-type" [hw label] (NHMUK).

Additional material studied (244 specimens).

Western Australia: 1 ex., "Australia07, WA 50, Parrys Lagoon, Marigu Billabong, 25 km SE Wyndham, 77 m, 15.32.98S 128.15.59E, M. Baehr" (ZSM); 1 ex., "AUSTRALIA/WA, Koolan Island [16°09'S, 123°45'E], VIII–IX 1967, Milton O. leg." (WAM); 1 ex., "AUSTRALIA/WA, Derby [-17.3166, 123.6333], 2.1962, Beamish, G. leg." (WAM); 1 ex., idem but „10.4.1964” (WAM). Northern Territory: 1 ex., "Australia, N.T. Binis Track 10.IV.2011 LF; H = 427 m 20°51'51.4"S, 135°12'01.6"E leg. Michael Langer" (ZSM); 1 ex., "Australia, NT, 80 km W Roper Bar, 14°54'19"S, 133°57'28"E, 78 m, at light, 14.V.2006, leg. Berger & Dostal (7/06)" (CGW); 1 ex., "Australia, NT, Kakadu NP, Muirella, 40 m, at light, 10.V.2006, leg. Berger & Dostal (3/06)" (CGW); 1 ex., "Katherine (T) Vestjens, 1.12.1967 [-14.51667, 132.3667], W.J.M. Tindal" (ANIC); 1 ex., "Katherine [-14.46667, 132.2667], 9.2.1968, Watson, J.A.L." (ANIC); 1 ex., "Howard Springs 27.01.1968 [-12.45, 131.05] Watson, J.A.L." (ANIC); 1 ex., "Northern Territory Katherine [-14.46667, 132.2667], 6.2.1968, Matthews, E." (ANIC); 1 ex., "Northern Territory, Lee Point, Darwin [-12.33333333, 130.9], 7.3.1967, Upton, M.S." (ANIC); 1 ex., "Northern Territory, Roper Gulf (S), Mataranka [-14.93333333, 133.0666667], 1.3.1967, Upton, M.S." (ANIC); 1 ex., "NT Davenport Murchison Ranges, Barkly (S), 15 miles N of Tennant Ck. [-19.4, 134.1833333], 27.2.1967, Upton, M.S." (ANIC); 1 ex., "NT Brock Creek, Burnside [Brocks Creek] [-13.46667, 131.4167], 27.3.1929, Campbell, T.G." (ANIC); 1 ex., "Howard Springs, Litchfield (M) [-12.45, 131.05], 27.1.1968, Matthews, E." (ANIC); 1 ex., "Australia N.T. Kununurra m 50 23.VIII.1996 P.M. Giachino legit" (CLH); 1 ex., "Australia N.T. Umbrawarra Gorge Campground, ca. 40 km S Pine Creek, 27.IV.-18.V.2009, S 13°58'01.4"S, 131°41'57.2"E, 163 m, NF, leg. M. Langer" (CLH); 2 exs.,"Australia: N.T./ ca. 30 km S Daly Waters und ca. 90 km N Elliott am Stuart Hwy 04.IV.2011 LF H = 269 m 16°46'38.8"S, 133°25'53.8"E leg. Michael Langer" (CLH); 11 exs., "Australia: NT, Litchfield NP, TJAYNERA FALLS, 13°15'S, 130°44'E, 63 m, S. Jákl leg., 20 –27.XI.2008” (NMPC); 5 exs., "AUSTRALIA: NT, 25 km S of KATHERINE, rd to Kununurra, 14°44'S, 132°01'E, 100 m, S. Jákl leg., 17. –31.XII.2008” (NMPC); 12 exs., "AUSTRALIA: NT, 25 km S of KATHERINE, nr Cutta Cutta caves, 14°31'S, 132°25'E, 168 m, S. Jákl leg., 23. –31.XII.2008” (NMPC); 1 ex., "Australia: NT, Nitmiluk NP, Edit Falls, 14°10'S, 132°06'E, 37 m, S. Jákl leg., 3.XII.2008" (NMPC); 2 exs., "AUSTR. NT, Mataranka, 14°53'S, 132°01'E, 18.12.08, 148 m, Sv. Bílý leg." (NMPC); 70 exs., "Australia: NT, 70 km SW of Mataranka, 15°19'S, 132°50'E, 190 m, S. Jákl leg., 22. –23.XII.2008” (NMPC); 1 ex., "AUSTRALIA: NT, West Macdonnell Range NP, SIMPSON GAP, 23°40'S, 133°43'E, 600 m, S. Jákl leg., 3. –5.I.2009” (NMPC). Queensland: 1 ex., "Cardstone [-17.76666667, 145.5833333], 16.12.1965, Hyde, K." (ANIC); 1 ex., "Mary Creek [-16.55, 145.2], 4.12.1968, Britton, E.B. & Misko, S." (ANIC); 1 ex., "Cairns [-16.91667, 145.7667] Taylor, F.H." (ANIC); 1 ex., "Queensland, Whitsunday, Mimosa Motel, 3 m. S Bowen [-20.01667, 148.25], 23.3.1967, Brooks, J.G." (ANIC); 1 ex., "Townsville [-19.26667023, 146.8166656], Taylor, F.H." (ANIC); 36 exs., "Australia/Queensland 30 km E Normanton riverside at light, 1.1996, S. Lamond leg. Coll. Hendrich" (CLH); 31 exs., "Australia/ Queensland 20 km E of Normanton February 1996, at light, Steven Lamond leg. Coll. L.Hendrich" (CLH); 4 exs., "Bowen N.Q. 23/III/1962 A. & M. Walford-Huggins" (CLH); 10 exs., "Australia, QL, Rollingstone, 20 km NW Townsville, 20 m, 17.I.1993, leg. G. Wewalka (7)" (CGW); 3 exs., "Australia, QL, Dalrymple, 30 km N Charters Towers, 300 m, 18.I.1993, leg. G. Wewalka (10, 11)" (CGW); 1 ex., "QL, 15 km S Ogmore, 24.I.2012, leg. S. Prepsl" (CGW); 3 exs., "Australia, Queensland, Horn Islet, Sir Edward Pellew Group, 15. February 1968-21. February 1964, B. Cantrell" (QM); 1 ex., "Australia, Queensland, Iron Range, Cape York 23. April 1966, G. Monteith" (QM); 2 exs., "Australia, Queensland, CYP Batavia Downs, 12.40S, 142.40E, 3. March 1993-10. March 1993, at light, I. Cunningham" (QDPIB); 6 exs., "Australia, Queensland, Tolga, 26. Jan.-31. Jan. 1981, at light, N. Gough" (QDPIB); 1 ex., "Australia, Queensland, Burketown 31. Jan. 1992, at light, B.M. Waterhouse, J.F. Grimshaw" (QDPIB); 1 ex., "Australia, Queensland Danbulla S.F. via Yungaburra 13. February 1992 at light, Storey, De Faveri & Huwer" (QDPIB); 1 ex., "Australia, Queensland, Normanton, 4. September 1982, at light, R.I. Storey" (QDPIB); 1 ex., "Australia Queensland Kauri Creek, Para Grass, 30. August 1995, B. Hebert" (QDPIB); 1 ex., "Australia, Queensland, Ingham, 6. March 1984 at light, K.H. Halfpapp" (QDPIB); 4 exs., "AUSTRALIA Qld. Windsor Tableland Feb 6-8/91 Larson & Storey" (ZSM); 2 exs., "N Queensland, 14.1.2000, Kuranda, Sv. Bílý leg." (NMPC); 1 ex., "N Queensland, 9.2.2000, Kuranda, Sv. Bílý leg." (NMPC); 1 ex., "N Queensland, 7.2.2000, Mt. Carbine, Sv. Bílý leg." (NMPC); 1 ex., "N Queensland, 13.2.2000, Undara, Sv. Bílý leg." (NMPC).

Description of male.

Body shape: In dorsal view oval, almost ovoid, broadest in basal third of elytra, moderately convex. Body outline without discontinuity between pronotum and elytra. Head relatively broad; anterior margin of clypeus truncate. Pronotum broadest between posterior angles, lateral margins moderately curved. Base of elytra as broad as pronotal base; lateral margins of elytra moderately curved ( Fig. 6 ).

Colouration. Body dark red-brown to black, clypeus anteriorly, sides of pronotum broadly and elytra laterally (including epipleura) paler, ventral side and appendages testaceous ( Fig. 6 ).

Dorsal surface sculpture: Whole surface almost matt ( Fig. 6 ). Head uniformly microreticulated, reticulation composed of moderately deeply impressed meshes. Punctation composed of coarse setigerous punctures, and very small punctures spreading sparsely on surface; rows of coarse punctures present around inner margin of eyes and in small depression anterolaterally of eyes. Pronotum with lateral beading very thin and indistinct. Microreticulation and punctation similar to that of head; row of coarse setigerous punctures present along anterior margin, basal margin (except for basomedially), and laterally close to sides. Elytra with microreticulation similar to that of head and pronotum, but less impressed. Serial punctures on elytra rather weak. On each elytron six moderately impressed thin discal and one submarginal longitudinal striae, progressively closer towards sides; stria 1 (sutural stria) reduced to apical fourth, striae 2 and 4 complete, striae 3 and 5 a little shorter basally. Submarginal stria short, expanding from behind middle of elytron to end of stria 6.

Antennae and legs: Antenna with antennomeres long and slender. Protibia modified, distinctly broadened anteriorly. Pro- and mesotarsomeres 1-3 distinctly broadened, with adhesive discs on their ventral side; claws simple.

Ventral part: Finely microreticulated, with intermixed, sparsely distributed, very small punctures. Prosternal process shortly lanceolate, apex obtuse; distinctly bordered laterally. Lateral parts of metaventrite tongue-shaped, slender. Metacoxal lines close, evenly and moderately diverging anteriorly, ending short of metasternum. Metacoxae and abdominal ventrites 1-3 with numerous longitudinal or oblique striae.

Male genitalia: Median lobe narrow, simple, tapering and slightly curved downwards apically in lateral view ( Fig. 15A, B, C ). Shape of paramere broadly triangular, with weak, relatively short setae, mainly along dorsal margin of subdistal part ( Fig. 15D ).

Female.

Similar to male in habitus. Protibia simple, not angled basally and only slightly broadened distally; pro- and mesotarsomeres not broadened, without adhesive setae. Pronotum basolaterally with numerous short longitudinal strioles. Elytra between striae and side with numerous short longitudinal strioles.

Measurements.

TL = 5.7-6.0 mm; TL-H = 5.3-5.6 mm; MW = 2.7-2.8 mm.

Variability.

All specimens studied are rather uniform and vary only in body length. In some specimens, the submarginal stria is reduced to few elongate grooves.

Differential diagnosis.

The species is close to C. tenebrosus but can be easily separated by the larger size, much shorter inner striae of elytra, and the form of the median lobe.

Distribution.

The species occurs in tropical and subtropical northern and central Australia, along the east coast south to Brisbane (WA, NT, QLD) ( Fig. 25 ). Additionally, C. marginatus was recorded from New Caledonia (South Province) and West Samoa by Wewalka et al. (2010). Zimmermann (1927: 17) reported the species from Tonga (two specimens from Tonga: Nukualofa, 22.xi.1925). He wrote also that the presence of the species in Samoa is confirmed by material of Dr K. Friederichs ( Friederichs 1922: 148: Samoa, five specimens). Later, C. marginatus was reported from Samoa (Upolu), Fiji (Viti Levu and Vanua Levu) and New Guinea (Dorey, now Manokwari, Indonesia: West Papua Province) by Balfour-Browne (1945: 106 and 113) which was repeated by some later authors ( Guéorguiev 1968: 21; Guéorguiev and Rocchi 1993: 159; Wewalka et al. 2010: 51). The records from Fiji and New Guinea are in need of confirmation.

Habitat.

Most specimens were collected during or just after the rainy season when the beetles can be collected in seasonal flood meadows along rivers and creeks, shallow roadside ditches and swampy areas. At that time of the year, C. marginatus is often attracted in larger numbers to light (e.g., Normanton). In north-eastern Queensland, the species was collected in a small roadside pool and in isolated pools in seasonal fingertip tributary streams, all in closed forest ( Larson 1993).

Figures

Figure 6. Habitus and colouration of Copelatus marginatus, female. Total length 5.8 mm.

Figure 15. Copelatus marginatus A median lobe in lateral view, right side B median lobe in lateral view, left side C median lobe in ventral view D left paramere in external view. Scale bar: 0.5 mm.

Figure 25. Distribution of Copelatus marginatus.