Copelatus irregularis W.J. Macleay, 1871

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 irregularis W.J. Macleay, 1871 Figures 5 , 14 , 23 , 31 , 34

Copelatus irregularis W.J. Macleay 1871: 126 (original description); Watts 1978: 126 (description); Watts 1985: 26 (general distribution); Larson 1993: 52 (habitat information); Larson 1997: 275 (habitat information); Hendrich 2003: 51 (new records); Watts 2002: 42 (checklist); Nilsson and Hájek 2019: 62 (catalogue).

Type locality.

"[Australia, Queensland] Lizard Island".

Type material.

ANIC, studied but the exact data not noted.

Material studied (221 specimens).

Western Australia: 8 exs., "WA, E-Pilbara, Weeli Wolli Springs, NW of Newman [555 m], 22°54.886'S, 119°12.661'E, 2005, C.H.S. Watts leg.", "DNA Balke 2655", "DNA Balke 2656" [green printed labels] (ZSM); 3 exs., "AUSTRALIA/WA/Shire of Wyndham - East Kimberley, Gibb River Raod, Barnett River Gorge, 16°32'15.17"S, 126°7'30.43"E, 450 m, 19.6.1999, Hendrich leg. Loc. 17/117" (CLH); 7 exs., "WA Palm Springs 9/09/2001, JSC" (DPAW); 4 exs., "WA Warrie Springs 8/09/2001 MDS" (DPAW); 4 exs., "AUSTRALIA WA, Mt Fanny 08/07/1969, Giles 50 mi 180, 25°47'S, 128°35'E, Giuliani D.D. leg." (WAM); 3 exs., "AUSTRALIA WA, Synnot Range 01/09/1969, 16°25'S, 125°28'E, Giuliani D.D. leg." (WAM); 1 ex., "AUSTRALIA/WA, Gill Pinnacle, 10/07/1969, 24°54'S, 128°47'E, Giuliani D.D. leg." (WAM); 2 exs., "AUSTRALIA/WA, Charnley River, 25 mi E Beverley Springs, 09/09/1969, 16°15'S, 125°26'E, Giuliani D.D. leg." (WAM); 4 exs., "AUSTRALIA/ WA, Nullagine [-21.8833, 120.1166] 19.-20.1.1974, Douglas A.M. & M.J. leg." (WAM); 2 exs., "AUSTRALIA/WA, Marandoo Camp, at light, 22°38'S, 118°06'E, 5.-19.5.1980, Houston, T.F. et al. leg." (WAM); 1 ex., "AUSTRALIA/WA, Lyons River, Mt Augustus, at light, 24°19'12"S, 116°49'48"E, 2.-3-IX.1980, Howard, C.A. & Houston, T.F. leg." (WAM); 1 ex., "Western Australia, Pilbara, Ashburton (S), Millstream, Deep Reach [-21.58333, 117.0667], 8.11.1970, Britton, E.B." (ANIC); 1 ex., "Australia, WA, Pilbara, Hamersley Range, 17 km S Auski Roadhouse, Fig. Tree Crossing 400 m, 28.8.2002, 22°32'S, 118°44'E, Hendrich leg. (Loc. WA 9/173)" (CLH); 2 exs., "Australia, WA, Pilbara, Hamersley Range, Karijini N.P., Dales Gorge [Fortescue Falls and Circular Pool], 400 m, 28.8.2002, 22°29'S, 118°35'E, Hendrich leg. (Loc. WA 10/174)" (CLH); 2 exs., "Australia, WA, Pilbara, Hamersley Range, Karijini N.P., Kalamina Gorge, 450 m, 29.8.2002, 22°25'S, 118°23'E, Hendrich leg. (Loc. WA 11/175)" (CLH); 1 ex., "Australia, WA, Pilbara, Hamersley Range, Karijini N.P., Knox Gorge, 450 m, 29.8.2002, 22°21'S, 118°18'E, Hendrich leg. (Loc. WA 12/176)" (CLH). 1 ex., "W AUSTRALIA, E-Pilbara, Weeli Wolli Springs, 22°54.886'S, 119°12.661'E, 555 m, xi.2001, M. Häckel leg." (NMPC). Northern Territory: 12 exs., "Australia NT, Trephina Gorge, East MacDonnell Ranges [-23.529, 134.375], October 1972, leg. M. Baehr" (CLH, ZSM); 1 ex., "Australia, NT, Litchfield NP, Florence Falls, 12°51'15"S, 132°45'16"E, 63 m, at light, 12.V.2006, leg. Berger & Dostal (5/06)" (CGW); 2 exs., "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, 40 km v. Port Roper, 14°54'04.8"S, 135°03'24.7"E, 134 m, 15.V.2006, leg. Berger & Dostal" (CGW); 1 male, "Australia, N.T./Kakadu N.P., Jim Jim District, Barramundie Gorge, Maguk, 50 m, 31.10.1996, 13°18.823'S, 132°26.198'E. L. Hendrich leg./ Lok. 9" (NMW); 8 males, 4 females, "Australia, N.T./Kakadu N.P., Gunlom Camp. Area, pool in Monsoonal Forest, ca. 50 m, 3.11.1996, 13°26.082'S, 132°24.929'E L. Hendrich leg./Lok. 15" (NMW); 1 male "Thorey 1867" [partly hw], "Nov: Holl: bor:" [hw], "Coll. Mus. Vindob." (NHW). 2 exs., "Australia: NT, Litchfield NP, TJAYNERA FALLS, 13°15'S, 130°44'E, 63 m, S. Jákl leg., 20 –27.XI.2008” (NMPC); 1 ex., "Australia: NT, Victoria Highway, 110 km to KUNUNURRA, 15°57'S, 129°33'E, 76 m, S. Jákl leg., 30.XI.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); 1 ex., "Australia: NT, 70 km SW of Mataranka, 15°1'S, 132°50'E, 190 m, S. Jákl leg., 22. –23.XII.2008” (NMPC); 2 exs., "Australia NT, 25 km S of Katherine, 168 m, 14°31'S, 132°25'E, 16.-17.1.2009, Sv. Bílý leg." (NMPC). Queensland: 2 exs., "AUSTRALIA, QLD. Mulgrave R, nr The Fisheries Nov. 9/90 Larson" (ZSM); 3 exs., "AUSTRALIA QLD. McLeod R nr base Windsor Tableland Nov. 12/90 Larson" (ZSM); 4 exs., "Australia S QLD, N Stradbroke Island, creek @Trans-island Rd. 1 km SE Brown Lake, 18.X.2014, 27°30'8.43"S, 153°26'10.78"E, Lars Hendrich leg. (QLD2/14)" (NMW); 1 ex., "QL, 35-47 km SWW Mt. Gamet, 31.I.-4.II.2012, leg. S. Prebsl" (CGW); 11 exs., "Australia, QL, Ravenshoe, 90 km W Innisfail, 900 m, 20.I.1993, leg. G. Wewalka (16)" (CGW); 18 exs., "Australia, QL, Greenvale, 150 km NW Charters Towers, 600 m, 19.I.1993, leg. G. Wewalka (12 –14)” (CGW); 6 exs., "Australia QLD/30 km NNW Mareeba, near Mitchell Lake, 9.11. 1996 Hendrich leg./Lok. 20" (CLH); 6 exs., "Australia: S QLD, 40 km E Bundaberg, Tusky Creek, 9 m, 26.IX.2006, 24.39.139S 152.01.477E, L. & E. Hendrich leg. (QLD 52)" (ZSM); 6 exs., "Australia: C QLD, 18 km S Calen, Mt. Charlton-Calen Road, Boulder Creek, 42 m, 23.IX.2006, 21.00.365S 148.43.231E, L. & E. Hendrich leg. (QLD 45)" (ZSM); 3 exs., "Australia: C QLD, 10 km S Mizani, Lake Kinchant, seapage, 48 m, 24.IX.2006, 21.11.580S 148.53.522E, L. & E. Hendrich leg. (QLD 46)" (ZSM); 11 exs., "Australia: C QLD, Paluma Road 4 km W Bruce Hwy, Maiden Hair Fern Crk., 270 m, 20.IX.2006, 19.00.162S 146.17.070E, L. & E. Hendrich leg. (QLD 40)", 4 specimens with "DNA Balke 1863", "DNA Balke 1864", "DNA Balke 2140", "DNA Balke 2141" [green printed labels] (CLH, ZSM); 2 exs., "Australia: S QLD, Winfield, Winfield Road, forest pool, 21 m, 26.IX.2006, 24.34.084S 152.00.513E, L. & E. Hendrich leg. (QLD 54)" (CLH); 1 ex., "Queensland, Pt. Denison [Port Denison, now Bowen -20.05, 148.25]" (ANIC); 1 ex., "Queensland, North Burnett (R) Gayndah, [-25.63333333, 151.6]" (ANIC); 1 ex., "Queensland Tablelands, N side of Lake Tinaroo, 9.11.1966 [-17.16667, 145.55], Britton, E.B." (ANIC). 1 ex., "Queensland, Tablelands, Mt. Lewis, tin working site, 3.12.1968 [-16.58333015, 145.2832947], Britton, E.B. & Misko, S." (ANIC); 1 ex., "Queensland, Townsville (C), Mt. Spec, 5.1.1965, -18.95, 146.1833333, Brooks, J.G." (ANIC); 1 ex., "Queensland Rockhampton (R) Pistol Gap, Byfield, 10.1.1970 [-22.83333333, 150.6666667], Britton, Holloway & Misko" (ANIC); 1 ex., "Queensland, 9 miles W of Paluma, Charters Towers (R), 15.4.1969 [-19.1, 146.0667], Common, I.F.B. & Upton, M.S." (ANIC); 1 ex., "North Queensland, Magnetic Island [-19.13333, 146.8333], Lea, A.M." (ANIC); 1 ex., "Queensland Tablelands (R) Mary Creek [-16.55, 145.2], 4.12.1968 Britton, E.B. & Misko, S." (ANIC); 1 ex., "Queensland, Townsville (general), 26.3.1968 [-19.26667023, 146.8166656] Ferrar, P." (ANIC); 1 ex., "Queensland, Cardstone, 16.12.1965 [-17.76666667, 145.5833333] Hyde, K." (ANIC); 1 ex., "Queensland, Townsville (general) [-19.26667023, 146.8166656], 21.12.1967, Ferrar, P." (ANIC); 1 ex., "Queensland Tablelands (R), Mary Creek, 5.12.1968 [-16.55, 145.2] Britton, E.B. & Misko, S." (ANIC); 1 ex., "QLD, Magnetic Island [-19.13, 146.83], A.M. Lea", “K.215158” (AMS); 1 ex., "Queensland [-22.82407, 147.63635] K.K. Spence", “K.215159” (AMS); 1 ex., "Queensland [-23.37805, 150.51361] T.G. Sloane", “K.215160” (AMS); 1 ex., "Queensland Magnetic Island [-19.13, 146.83] A.M. Lea", “K.215161” (AMS); 1 ex., "Queensland Hayman Island [-20.0508, 148.88783] Jan 1935, F.A. McNeil", “K.215162” (AMS); 1 ex., "Australia Queensland [-22.82407, 147.63635], “K.215163” (AMS); 1 ex., "Australia Queensland, The Rock Pool, Carnarvon NP [-25.06756, 148.246259] 26 Apr 2006, at MV lamp, D.R. Britton, J.R. Weiner, “K.363072” (AMS); 1 ex., "Australia, Queensland, Tewah Creek via Tin Can Bay, 17. October 1970, T. Weir" (QM); 1 ex., "Australia, Queensland, Baldy Mt. Road, 6 miles SW Atherton, 1100 m, 27. December 1972, B.K.Cantrell" (QM); 1 ex., "Australia, Queensland, Bald Hills Station 4 km N of Isabella Falls, 15°15' 145°00', 29. December 1984, mv lamp, G. & A. Daniels" (QM); 2 exs., "Australia, Queensland, Kenilworth State Forest, via Kenilworth, 20. October 1972, B.K. & J.A. Cantrall" (QM); 4 exs. "Australia, Queensland, Davies Creek via Mareeba, 27. Nov. 1981, R.I. Storey" (QDPIB); 2 exs., "Australia Queensland, Walkamin, 20. March 1984, light trap, J.D. Brown" (QDPIB); 1 ex., "Australia, Queensland Danbulla S.F. via Yungaburra, 13. February 1992, at light, Storey, De Faveri & Huwer" (QDPIB); 1 ex., "Australia, Queensland, 10. Dec. 1985, 15 km WNW of South Johnstone, light trap, Fay & Halfpapp" (QDPIB); 1 ex., "Australia, Queensland, 9. IX. 1985, 15 km WNW of South Johnstone, light trap, Fay & Halfpapp" (QDPIB); 4 exs., "Australia, Queensland, 23 km E of Mareeba, 29. January 1989, at light, R.I. Storey" (QDPIB); 2 exs., "Australia, Queensland, Tolga, 10. December 1982, light trap, J.D. Brown" (QDPIB); 1 ex., "Australia, Queensland", Paluma, 9.-13. January 1989, light trap, rainforest, R.I. Storey (QDPIB); 1 ex., "Australia, Queensland, Windsor Tableland, 16. December 1984, at light, R.I. Storey (QDPIB); 1 ex., "Australia, Queensland, Garradunga, 17. December 1992, J. Hasenpusch" (QDPIB); 1 ex., "Australia, Queensland, Mt. Mulligen Plateau, 700 m, 15.-19. IV. 1985, at light, K.H. Halfpapp" (QDPIB); 1 ex., "Australia, Queensland, Yam Island 24-27 March 1988, at light, Fay, Halfpapp" (QDPIB); 1 ex., "Australia, Queensland, Pinnarendi Station 60 km W of Mt. Garnet, 7. February 1989, D. Heiner" (QDPIB); 3 exs., "N Queensland, 15.1.2000, Davis Creek, Sv. Bílý leg." (NMPC); 1 ex., "N Queensland, 29.1.-3.2.2000, The Lynd Junction, Sv. Bílý leg." (NMPC); 6 exs., "N Queensland, 5.2.2000, Ravenshoe, Sv. Bílý leg." (NMPC); 3 exs., "N Queensland, 13.2.2000, Undara, Sv. Bílý leg." (NMPC).

Doubtful record.

1 ex., "Tasmania, Gladstone, Dorset, A.M. Lea" (SAMA), probably mislabelled.

Description of male.

Body shape: In dorsal view, oblong oval, broadest at midlength of elytra, moderately convex. Body outline almost continuous, with slight discontinuity between pronotum and elytra. Head relatively broad; anterior margin of clypeus not bordered. Pronotum broadest just before posterior angles, lateral margins moderately curved. Base of elytra as broad as pronotal base; lateral margins of elytra moderately curved ( Fig. 5 ).

Colouration: Body black, most of clypeus, sides of pronotum, base and tip of elytra, appendages and much of ventral surface testaceous ( Fig. 5 ).

Dorsal surface sculpture: Whole surface shiny ( Fig. 5 ). Head uniformly microreticulated, reticulation composed of moderately deeply impressed isodiametric very small meshes. Punctation composed of very small punctures sparsely spread on surface; rows of deep and coarse punctures present around inner margin of eyes and in small depression anterolaterally of eyes. Pronotum with some moderately strong, short striae, more dense and weak laterally; lateral beading of pronotum very thin and indistinct. Microreticulation and punctation similar to that of head; row of coarse setigerous punctures present along anterior margin, basal margin (except basomedially), and laterally close to sides. Elytra with microreticulation similar to that of head and pronotum, but less impressed. Punctation consisting of very fine sparse punctures. Each elytron with 11 strongly impressed discal and one submarginal longitudinal striae, intervals subequal, alternate striae tending to be shorter apically; submarginal stria reaching from little behind middle of elytron almost to end of stria 10. Serial punctures on elytron untraceable.

Antennae and legs: Antenna with antennomeres long and slender. Protibia modified, distinctly broadened anteriorly (2/3rd) and strongly narrowed basally (1/3rd). 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 rather flat, distinctly bordered laterally, weakly and bluntly pointed. Lateral parts of metaventrite tongue-shaped, very slender. Metacoxal lines close, well-marked and moderately divergent anteriorly. Metacoxae with some short and deep striae, abdominal ventrites 1-3 with numerous longitudinal striae.

Male genitalia: Median lobe consisting of a few sclerites, well separated apically ( Fig. 14A, B, C ). Shape of paramere narrowly triangular, with very dense, strong, long setae along dorsal margin ( Fig. 14D ).

Female.

Similar to male in habitus. Pro- and mesotarsomeres not broadened, without adhesive setae. Pronotal striae fine and dense.

Measurements.

TL = 6.8-7.8 mm; TL-H = 6.0-6.9 mm; MW = 3.2-3.4 mm.

Variability.

All specimens studied are rather uniform in shape and size but vary in the extension of the testaceous elytral markings.

Differential diagnosis.

The species is close to C. bakewelli but can be easily separated by the larger size, the dorsal colouration, and the form of the median lobe.

Distribution.

The species is widely distributed in the northern half of Australia. Records are from the Northern Territory (inland to the East MacDonnell Ranges), north-western Australia (Kimberley region and the Pilbara), and Queensland south to Brisbane ( Fig. 23 ).

According to the literature, C. irregularis occurs also in New Guinea, cited in Guignot (1956: 55) and Zimmermann (1920: 140); Papua in Guéorguiev (1968: 9); Papua New Guinea: Central Province: Redscar Bay in Régimbart (1899: 306) and Guéorguiev and Rocchi (1993: 158). However, all these records are in need of confirmation.

Habitat.

This is a widely distributed species and one of the most common Copelatus in tropical northern Australia. It can be found in almost all habitat types, preferably in forested areas. Most specimens were obtained from shallow water, amongst leaves and plant debris, of isolated pools of seasonal creeks and streams, and pools adjacent to streams in Eucalypt or tropical woodland. Also, a few specimens were taken from slow flowing spring-fed streams. In the Pilbara (Hendrich 2002), C. irregularis was found in different isolated and half-shaded rocky and sandy pools (10-20 m², up to 1.5 m depth) of an intermittent stream. The bottom of most habitats consisted of sand and stones, with a thin layer of mud and plant debris ( Figs 31A , 34A ). Copelatus irregularis is also attracted to light.

Figures

Figure 5. Habitus and colouration of Copelatus irregularis, male. Total length 7.7 mm.

Figure 14. Copelatus irregularis 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 23. Distribution of Copelatus irregularis.

Figure 31. Habitat of Copelatus irregularis and C. clarki A residual pool of the stream bed of Oakly Creek, Queensland (Loc. 28) B only of C. clarki, Stradbroke Island, temporary sedge swamp near Brown Lake, Queensland. Photographs by L. Hendrich.

Figure 34. Habitat of Copelatus irregularis A Queensland, Paluma Road 4 km west of Bruce Highway, Maiden Hair Fern Creek, 270 m, shady and rocky residual pools with rotten leaves B of C. irregularis and C. nigrolineatus, Queensland, Winfield, Winfield Road, muddy forest pool, rich in rotten leaves, near the street, 21 m. Photographs by L. Hendrich.