Batrachomatus daemeli (Sharp, 1882)

Hendrich, Lars & Balke, Michael, 2013, Revision of Australian Matini diving beetles based on morphological and molecular data (Coleoptera, Dytiscidae, Matinae), with description of a new species, ZooKeys 293, pp. 41-64 : 44-46

Batrachomatus daemeli (Sharp, 1882)

Matus daemeli Sharp, 1882: 600 (orig. descr.); Zimmermann 1920: 194 (cat.).

Batrachomatus daemeli (Sharp, 1882): Zimmermann 1919: 215 (comb. n.); Mouchamps 1964: 137 (descr.); Watts 1978: 119 (descr.); Watts 1985: 23 (cat.); Lawrence et al. 1987: 351 (cat.); Nilsson 2001: 261 (cat.); Watts 2002: 31, 46 (cat.).

Batrachomatus burnsi Mouchamps, 1964: 138; Watts 1978: 119 (comb. n.).

Batrachomatus burnsi var. obscurior Mouchamps, 1964: 140 (orig. descr.), syn. n.

Type locality.

Sydney, New South Wales, Australia.

Type material studied.

Lectotype ♂ of Matus daemeli : “Lectotype” [ Watts des. 1978: 119], “Type”, "Sydney Austr" [handwritten label], “S.Australia”, "Sharp Coll. 1905-313", "Type 860 B. Daemeli" [handwritten label], "Batrachomatus daemeli Sydney" [handwritten label], "Matus daemeli Sharp Det. C. Watts 1979" (BMNH). Holotype ♂ of Batrachomatus burnsi : "Macalister River, XI.1946, F.E.Wilson leg", “Holotype” [red printed label], "Batrachomatus burnsi sp.n. Mouchamps" [handwritten and printed label] (MVMA).

Additional material studied

(142 specimens): Queensland: 3 exs., "N QLD, Atherton Tableland, Millaa Millaa Falls, 2500 feet, IV.1932, Australia Harvard Exp. Darlington" (ANIC, SAMA); 1 ex., "S QLD, Brisbane, 1.I.1952, C.Oke leg." (MVMA). Australian Capital Territory: 1 ex., "Canberra, I.1961, C.H.S. Watts leg." (SAMA). New South Wales: 4 exs., "N NSW, 20 km NE Tenterfield, Boonoo Boonoo River Cross., 949m, 12.X.2006, 28° 52.486S, 152° 06.246E, L. & E. Hendrich leg." (NSW 67) (CLH, ZSM); 21 exs., "N NSW, 35-40 km S Grafton, road [Orara Way] to Coffs Harbour, Flaggy Creek NR, 5m, 15.X.2006, 29.58.587S, 152.58.452E, L. & E. Hendrich leg. (NSW 77)", one specimen with green printed label "DNA M.Balke 1829" (CLH, ZSM); 6 exs., "C NSW, Glouchestershire, Barrington River at Barrington, 133m, 18.X.2006, 31° 58.225S, 151° 54.160E, L. & E. Hendrich leg. (NSW 82)", one specimen with green printed label "DNA M.Balke 1799" (CLH); 8 adults and 14 larvae (LA III), "C NSW, 3 km W Albion Park, North Macquarie Road at creek crossing, 19m, 30.X.2006, 34° 34.337S, 150° 43.456E, L. & E. Hendrich leg. (NSW 87)" (CLH); 8 exs., "C NSW, Endrick River at Braidwood Road, 554m, 1.XI.2006, 35° 05.193S, 150° 07.182E, L. & E. Hendrich leg. (NSW 94)" (CLH); 9 ex., "C NSW, 10 km W Braidwood, Shoalhaven River at Bombay Bridge, 628m, 2.XI.2006, 35° 25.419S, 149° 42.582E, L. & E. Hendrich leg. (NSW 96)" (CLH, ZSM); 4 exs., "S NSW, Wallagaraugh River Picnic Area, 43 km SW Eden, 54m, 17.XI.2006, 37.22.079S 149.43.073E, L. & E. Hendrich leg. (NSW 112)", four specimens "DNA M.Balke 2371", "DNA M.Balke 2373", "DNA M.Balke 2374", "DNA M.Balke 2375" (CLH, ZSM); 1 ex., "Williams River near Dungog, 27.XI.1996, C.H.S. Watts leg." (SAMA); 5 exs., "5 km W Bombala, Saucey Creek, 18.I.1997, C.H.S. Watts leg." (SAMA); 24 exs., "Eccleston, J. Hopson" (ANIC, SAMA); 2 ex., "N NSW, Caparra (Lots 72, 73, 148) 35 km NW Taree, 3.I.1990" (ANIC); 2 exs., "Kindee N.S.W Sept. 1934 H.J. Carter", "Batrachomatus daemeli Shp. Det. C. Watts 1971", "K 215108" (AMS); 1 ex., "N NSW, Kindee [Kindee Creek] 50 km W Port Macquarie, IX.1934" (ANIC); 1 ex., "C NSW, Shoalhaven River, 3.I.2001, W.D. Shepard leg." (ANIC); 1 ex., "C NSW, Wollondilly R. Jooriland, 60 km W Wollongong, 16.XII.1931" (ANIC); 1 ex., "NSW EPA Survey MRHI SHOA (Shoalhaven River System) 01, Kangaroo River and Gerrigong Creek, 26.XI.1997, 34° 41.17S, 150° 35.58E J. Potts leg. K 227447 Riffle" (AMS); 1 ex., "NSW EPA Survey MRHI CLYD (Clyde River System) 13 d/s, Bimberamala River, 25.X.1995, 35° 25.59S, 150° 11.36E, A. Leask leg. EPA 08191 Edge" (AMS); 1 ex., "NSW EPA Survey MRHI SHOA 08 (Shoalhaven River System), Upper Corang River, 22.XI.1995, 35° 12.19S, 150° 03.24E, J. King leg., K 227320, edge" (AMS); 1 ex., "NSW EPA Survey MRHI HAST (Hastings River) 10 Forbes River: Round Flat, 2.X.1994, 31° 20.20S, 152° 20.23E, E. Turak leg., EPA 10992, logs" (AMS);8 exs., "S NSW, Albury, 16.VII.1989, P. Walker leg." (SAMA). Victoria: "6 exs., E VIC, Thurra River at Hwy 1, Water Point Rest Area, 138m, 5.XI.2001, 37° 34.061S, 149° 16.338E, G.L.Challet leg." (CGC, ZSM); 5 exs., "C VIC, Hughes Creek at Avenel, 161m, 25.XI.2006, 36° 54.221S, 145° 14.191E, L. & E. Hendrich leg. (VIC 120)", one specimen with green, printed label "DNA M.Balke 2763", "DNA M.Balke 2764", "DNA M.Balke 2765" (CLH); 1 ex., "Western District Lakes Surv 78, 16.I.1980, W.D.Williams leg." (SAMA); 1 ex., "Tamao Crossing, 24.I.1960, A.Neboiss leg." (MVMA); 2 exs., "Maffra, I.1939, F.E.Wilson leg." (MVMA). Tasmania: 1 ex., "Deloraine, Deloraine River, I.1961, C.H.S.Watts leg." (SAMA).

Description.

Measurements. TL = 7.9-9.1 mm, TL-H = 7.3-8.2 mm; MW = 4.0-4.6 mm.

Colour. Dorsal surface shiny, head, pronotum and elytra black, legs dark reddish, antennae and palpi reddish pale. Some specimens with reddish basal markings on elytra (Figs 1, 2, 3).

Structure and sculpture. Body outline oblong oval. Dorsal surface densely and evenly covered with small punctures, and with a very fine, almost subobsolete close reticulation with large meshes. Serial punctures on elytron distinct, large and shallow. Ventral surface finely and densely punctate. Prothoracic process broad, flat, apex pointed, broadly grooved in middle for whole length, sides strongly margined. Metacoxal lines raised, well separated, reaching almost to hind margin of metaventrite, diverging a little anteriorly.

Male. Pro- and mesotarsi dilated and stouter than in female, furnished beneath with dense, short, stout setae arranged in groups, many of the setae ending in minute suction cups. Aedeagus: median lobe in lateral (Figs 8a) and in ventral view (Figs 8b); paramere (Fig. 8c).

Variability. A very variable species in size and colour. Specimens having reddish shoulders of various form and extension were named Batrachomatus burnsi Mouchamps, 1964 (Fig. 2, large red patch on the shoulder) and Batrachomatus burnsi var. obscurior (smaller and interrupted reddish patch on shoulder). Such specimens can be found all over the species distributional range.

According to our study of the complete material of Batrachomatus daemeli two different forms can be recognized: larger specimens (see measurements above) with larger median lobes and smaller specimens [Measurements: TL = 7.3-8.0 mm, TL-H = 6.5-7.05 mm; MW = 3.6-3.9 mm] (Fig. 3) with smaller and less elongated median lobes. The latter have been collected at several places in New South Wales and Victoria, sometimes syntopic with the larger form. Despite the fact that intergrades between the typical Batrachomatus daemeli and the "smaller form" have been found, for some time we even have been strongly tempted to describe those smaller specimens as another new species. On the other hand we have not been able to find any constant extern morphological character-except of the size-and also the shapes of the male genitalia are more or less the same. In addition, in our cox1 tree (Fig. 15) specimens of both forms aregrouped in the same clade.

Affinities.

Batrachomatus daemeli differs from the northern Australian Batrachomatus larsoni sp. n. and Batrachomatus wingii in the broader, more oblong shape, the lack of colour pattern on upper surface in most specimens, the weakly diverging metacoxal lines and the shape of the median lobe.

Distribution.

The most widespread and common species of the genus in Australia (Fig. 13). From the Atherton Tableland in Queensland along the east coast of New South Wales, Canberra area, to western Victoria and north-eastern Tasmania ( Watts 1978).

Habitat.

Batrachomatus daemeli inhabits permanent streams, creeks and slow flowing larger rivers at an altitude from about sea level to almost 1000 m, from more or less open country in cultivated areas to closed-canopy forest sites (Figs 20-23). Most specimens were found in low-gradient stream or river sections where the substrate was enriched with rotten leaves, wood and larger stones. In this habitat the beetles were found in areas of medium, laminar flow, generally in deeper water (50 cm depth and more) under larger logs and stones. When disturbed the adults can be observed swimming around and coming to the surface. In dryer periods the species can be found in the deepest parts of the remaining rest pools of a creek or river. All the mentioned smaller specimens from Coffs Harbour, Flaggy Creek were collected in a peaty and intermittent creek, with muddy bottom, shaded by wet eucalypt forest. The adults were mainly being located in a mixture of water and mud under a larger rotten tree trunk (Fig. 20). At this site Batrachomatus daemeli was associated with the rarely collected Sternopriscus wallumphilia Hendrich & Watts, 2004, a dytiscid known before only from its type locality, a single creek in the Wallum heath near Glasshouse Mountains in southern Queensland (Hendrich and Watts 2004). In New South Wales the larvae of Batrachomatus daemeli were collected together with the adults in October and November. Adults can be found all over the year.