Austrelatus gen. nov., a new genus of Australasian diving beetles (Coleoptera, Dytiscidae, Copelatinae), with the discovery of 31 new species from New Guinea
Authors: Shaverdo Helena , Hájek Jiří , Hendrich Lars , Surbakti Suriani , Panjaitan Rawati , Balke Michael 
Published: July 2023

Herein,Austrelatusgen. nov.(type species:Copelatus irregularisW.J. Macleay, 1871) is described for a distinctive lineage of predominantly Australasian species previously assigned toCopelatusErichson, 1832. The new genus was retrieved as well supported, monophyletic clade in phylogenetic analysis of DNA sequences data using Bayesian and parsimony approaches. The main morphological diagnostic character ofAustrelatusis a complex median lobe of the aedeagus, with evident dorsal and ventral sclerites usually divided in apical half into two lobes of different shape or otherwise modified. Morphological comparison of the new genus with other Copelatinae genera, especially withCopelatusandExocelinaBroun, 1886, and a generic key to the New Guinean Copelatinae are provided. New combinations are established for 31 already described species mainly from the Australian Region (all fromCopelatus):Austrelatus adelbert(Megna, Atthakor, Manaono, Hendrich & Balke, 2017),comb. nov.;A. badeni(Sharp, 1882),comb. nov.;A. bakewelli(J. Balfour-Browne, 1939),comb. nov.;A. baranensis(Hájek, Shaverdo, Hendrich & Balke, 2021),comb. nov.;A. bougainvillensis(Hájek, Shaverdo, Hendrich & Balke, 2021),comb. nov.;A. boukali(Hendrich & Balke, 1998),comb. nov.;A. clarki(Sharp, 1882),comb. nov.;A. daemeli(Sharp, 1882),comb. nov.;A. davidi(Wewalka, 2017),comb. nov.;A. deccanensis(Sheth, Ghate & Hájek, 2018),comb. nov.;A. fidschiensis(Zimmermann, 1928),comb. nov.;A. gestroi(Régimbart, 1892),comb. nov.;A. irregularis(W.J. Macleay, 1871),comb. nov.;A. kaszabi(Guignot, 1956),comb. nov.;A. kietensis(Hájek, Shaverdo, Hendrich & Balke, 2021),comb. nov.;A. laevipennis(Hájek, Shaverdo, Hendrich & Balke, 2021),comb. nov.;A. luteomaculatus(Guignot, 1956),comb. nov.;A. maushomi(Sheth, Ghate & Hájek, 2018),comb. nov.;A. neoguineensis(Zimmermann, 1919),comb. nov.;A. nigrolineatus(Sharp, 1882),comb. nov.;A. papuensis(J. Balfour-Browne, 1939),comb. nov.;A. parallelus(Zimmermann, 1920a),comb. nov.;A. schuhi(Hendrich & Balke, 1998),comb. nov.;A. sibelaemontis(Hájek, Hendrich, Hawlitschek & Balke, 2010),comb. nov.;A. strigosulus(Fairmaire, 1878),comb. nov.;A. ternatensis(Régimbart, 1899),comb. nov.;A. uludanuensis(Hendrich & Balke, 1995),comb. nov.;A. urceolus(Hájek, Shaverdo, Hendrich & Balke, 2021),comb. nov.;A. variistriatus(Hájek, Shaverdo, Hendrich & Balke, 2021),comb. nov.;A. wallacei(J. Balfour-Browne, 1939),comb. nov.andA. xanthocephalus(Régimbart, 1899),comb. nov.Austrelatusspecies from New Guinea are divided into two informal species groups, theA. neoguineensisgroup andA. papuensisgroup, andA. fumatosp. nov.andA. setiphallussp. nov.standing aside of them. TheA. neoguineensisgroup is introduced with three previously known species and 29 new species described here based on the morphological characters and Cox1 data:Austrelatus baliemsp. nov.,A. bormensissp. nov.,A. brazzasp. nov.,A. debulensissp. nov.,A. fakfaksp. nov.,A. febrisaurisp. nov.,A. fojaensissp. nov.,A. garainensissp. nov.,A. innominatussp. nov.,A. lembenensissp. nov.,A. lisaesp. nov.,A. manokwariensissp. nov.,A. mimikasp. nov.,A. mirificussp. nov.,A. moreguinensissp. nov.,A. nadjaesp. nov.,A. oksibilensissp. nov.,A. pseudoneoguineensissp. nov.,A. pseudoksibilensissp. nov.,A. rajaampatensissp. nov.,A. rouaffersp. nov.,A. rugosussp. nov.,A. sandaunensissp. nov.,A. sarmiensissp. nov.,A. securiformissp. nov.,A. testegensissp. nov.,A. toricellisp. nov.,A. vagauensissp. nov., andA. wanggarensissp. nov.Copelatus vagestriatusZimmermann, 1919,syn. nov.is recognised as a junior subjective synonym ofA. clarki(Sharp, 1882). The lectotypes ofCopelatus gestroiRégimbart, 1892,C. neoguineensisZimmermann, 1919 andC. xanthocephalusRégimbart, 1899 are designated. All species are (re)described, and their important species characters (genitalia, habitus, and colour patterns) are illustrated. Keys to all species are provided. The known distribution and habitat preferences of each species are outlined briefly. New GuineanAustrelatusoccupy a variety of stagnant water habitats, either lenticsensu stricto, or standing water associated with lotic habitats (e.g., backflows, rockpools, intermittent / ephemeral stream pools).