SPIXIANA 39 2 213-218 München, Dezember 2016 ISSN 0341-8391 A new epigean Paroster Sharp, 1882 from coastal New South Wales, Australia (Coleoptera, Dytiscidae, Hydroporini) Lars Hendrich & Michael Balke Hendrich, L. & Balke, M. 2016. A new epigean Paroster Sharp, 1882 from coast- al New South Wales, Australia (Coleoptera, Dytiscidae, Hydroporini). Spixiana 39 (2): 213-218. Paroster lorimeri spec. nov. is described from Bombah Point Swamp, in the Myall Lakes National Park, in coastal New South Wales, Australia. The type locality marks the north-eastern-most record of an aquatic epigean species of the Austral- ian Paroster Sharp, 1882. It is very similar to Paroster gibbi Watts, 1978 from S Vic- toria and S Australia but well characterized by its stronger microreticulation, form of median lobe, and slightly enlarged male antennomeres 6-10. Paroster lorimeri spec. nov. is most probably a lentic species, being sieved from leaf litter at the edge of a coastal and ephemeral sedge swamp. Important species characters (habitus, male antennae and median lobe) are illustrated. The total number of described epigean aquatic Paroster is now 15. Lars Hendrich, SNSB – Zoologische Staatssammlung München, Münchhausen- straße 21, 81247 München, Germany; e-mail: [email protected] Michael Balke, SNSB – Zoologische Staatssammlung München, Münchhausen- straße 21, 81247 München, Germany; e-mail: [email protected] Introduction now known to be a world hotspot for such organ- isms. Within Paroster, the stygobitic species are The diving beetle genus Paroster Sharp, 1882 is en- morphologically very similar, with, apart from male demic in Australia. Its epigean species were revised sexual characters, only colour and size separating by Watts & Leys 2008 who described three new many of them. The stygofauna is concentrated on species. According to the results of a comprehensive the Yilgarn area in Western Australia, inland of phylogeographic study of the Australian Hydro- Northern Territory and South Australia (Watts & porini by Toussaint et al. (2014) Paroster is sister Humphreys 1999, 2003, 2006, 2009, Leys et al. 2010). of a clade of ([Necterosoma] + [Carabhydrus + {Bar- Most authors aiming at deciphering the origin of retthydrus + Sternopriscus}]).Two terrestrial species, hypogean taxa proposed that these lineages might described under the genus name Terradessus Watts, have colonized underground ecosystems in response 1985, and living in wet soil of Queensland rainforests, to climatic change (e. g. Leys et al. 2003). For Aus- were recently transferred to Paroster (Toussaint et al. tralian diving beetles, the dominant hypothesis has 2016). Most species diversity of Paroster is, however, proposed that the Paroster radiation is the result of found in underground waters of Australia. a groundwater colonization following the onset of Within the last two decades, biological surveys, Miocene aridification at ca. 15 million years (Ma) often associated with environmental impact assess- ago. At this time, epigean populations might have ments of mining and other projects, have greatly colonized subterranean aquifers to avoid increasing increased knowledge about Australian stygofauna aridity (Leys et al. 2003). (Leys et al. 2003). Especially Western Australia is 213 The epigean species are mainly distributed in SW Taxonomy Australia and the southern parts of South Australia and Victoria (Watts & Leys 2008). The habitat prefer- Checklist of epigean and aquatic species ence is lentic living in temporary creeks, swamps, of Paroster flooded areas and puddles on isolated granite outcrops in the south-west of Australia (so called Paroster acutipenis Watts & Leys, 2009 “pan-gnammas”) that form in late winter and early Central Western Australia spring but are dry by mid to late summer (Hendrich Paroster baylyi Hendrich & Fery, 2008 & Fery 2008). In many places, particularly shallow SW of Western Australia gutters and pools, they are the dominant species and Paroster couragei Watts, 1978 occur in considerable numbers for a relatively short SW of Western Australia time in spring. Usually adults cannot be observed Paroster ellenbrookensis Watts & Leys, 2009 well before the water has dried up (Watts & Leys SW of Western Australia 2008). Paroster gibbi Watts, 1978 Altogether 51 species, 15 epigean, two terrestrial South Australia, Victoria and 34 species of the stygofauna belong to the genus Paroster insculptilis (Clark, 1862) Paroster now (Nilsson 2016, Toussaint et al. 2016; South Australia, Victoria this paper). The aim of this paper is to describe a Paroster lorimeri spec. nov. new species from coastal New South Wales, which New South Wales marks the north-eastern most distribution record of Paroster leai Watts & Leys, 2009 an aquatic epigean Paroster species. SW of Western Australia Paroster michaelseni Régimbart, 1908 SW of Western Australia Material and methods Paroster niger Watts, 1978 SW of Western Australia The beetles were studied with a Leica MZ 12.5 stereo Paroster nigroadumbratus (Clark, 1862) microscope at 10-100 × magnification. Drawings of the South Australia, Victoria male genitalia were made based on digital images. Paroster pallescens Sharp, 1882 Photographs of the habitus were taken with a digital SW of Western Australia photo imaging system, composed of a Leica Z 6 APO Paroster sharpi Watts, 1978 and a Nikon V3 camera. Image stacks were aligned and assembled with the computer software Helicon Focus SW of Western Australia 4.77TM. Paroster thapsinus (Guignot, 1955) The following abbreviations were used in the text: South Australia, New South Wales TL (total length), TL-H (total length without head), and Paroster ursulae Hendrich & Fery, 2008 MW (maximum width). The terminology to denote the SW of Western Australia orientation of the genitalia follows Miller & Nilsson (2003). Label data of the type material are cited in quo- tation marks and the style of the descriptive notes fol- Genus Paroster Sharp, 1882 lows Watts & Leys (2008) and Hendrich & Fery (2008). We used Google Earth (http://earth.google.com) to Within the tribe Hydroporini, Paroster can be recog- locate localities and the coordinates are given in De- nised by their exposed metatrochanter bases, evenly grees, Minutes (DDD° MM'). Our map bases on “MI- punctate metatibia and relatively strong microreticu- CROSOFT ENCARTA World-Atlas 2000”. Specimens mentioned in this work are deposited in lation, particularly in the females. The metacoxae are several collections which are abbreviated in the text as closely adpressed to the first abdominal segment. The follows: metacoxal cavities are exposed and well separated, AM Australian Museum, Sydney, Australia and the metacoxal processes produced backwards in ANIC Australian National Insect Collection, Canberra, the midline. The middle and the posterior portions Australia of the epipleuron are very narrow, and crossed by CLH Collection Lars Hendrich, Munich, Germany; an oblique carina near the shoulders (Watts 1985, property of NMW 2002, Hendrich & Fery 2008). NMW Naturhistorisches Museum Wien, Austria SAMA South Australian Museum, Adelaide, Australia ZSM Zoologische Staatssammlung, München, Germa- ny 214 1 2 Figs 1-2. Paroster lorimeri spec. nov., male, holotype (1) and P. gibbi, male (2). Scale bar = 1 mm. Paroster lorimeri spec. nov. Head. Dark testaceous. Microreticulation deeply marked, meshes small, round/oval; sparsely and Type locality. Bombah Point Swamp [032°30' S 152° unevenly covered with small punctures, mostly little 17' E], Myall Lakes National Park, New South Wales, smaller than reticulation meshes. Antennae relatively Australia. short, stout. Antennal segments testaceous. Type material. Holotype, male: “Australia-NSW Bom- Pronotum. Dark testaceous, front and rear bah Point Swamp 032°30' S 152°17' E 1 May 1993 VWH margins in central half narrowly dark-testaceous to Lorimer”, “leaf-litter/detritus in swamp VWHL-347” black, area between them tending lighter laterally; (AM). – Paratypes: 1 male and 2 females with same data microreticulate as on head, sparsely covered with as holotype (AM, CLH, ZSM). unevenly distributed punctures, those on disc same size as those on head, denser and larger along front Diagnosis. Small, dark testaceous, oval and rela- and rear margins. tively flat bodied Paroster. Lateral outline of junc- Elytron. Evenly dark-testaceous; microreticula- tion of pronotum and elytra smooth, not slightly tion very strong, meshes as on pronotum, moder- sinuate (Fig. 1). ately, evenly covered with large well-marked and Description deep punctures larger than those on rear of prono- tum, serial punctures hard to trace. Measurements. Holotype: TL = 2.15 mm, TL-H = Ventral surface. Pronotal process quite broad, 1.9 mm; MW = 1.0 mm. Paratypes: TL = 2.0-2.15 mm, strongly keeled, tip pointed, reaching mesoventrite. TL-H = 1.75-1.90 mm; MW = 1.0 mm. Metathorax with lateral extensions of metaven- 215 5 a b 3 4 Figs 3-4. Left antennae in dorsal view of Paroster lorime- ri spec. nov. (5) and of P. gibbi (6). Scale bar = 0.3 mm. trite short; moderately microreticulate, with a few relatively strong punctures. Metacoxal plates large, weakly depressed in midline, quite strongly micro- reticulate, meshes fine; rather sparsely covered with large punctures, coxal lines relatively close, weakly 1 diverging in front /2, reaching metathorax. Ventrites microreticulate, punctures smaller than those on metacoxal plate. Appendages rufo-piceous. 6 a b Male. Protarsomeres broadened and proximally Figs 5-6. 5. Paroster lorimeri spec. nov.: Median