Australian Sphaeridiinae (Coleoptera : Hydrophilidae): A taxonomic outline with descriptions of new genera and species

Abstract

Twelve new genera and 28 new species of Sphaeridiinae from Australia are described: Eurygmus gen. nov. erected for E. helocharoides sp. nov.; Borborophorus gen. nov. erected for B. punctatus sp. nov., B. pubescens sp. nov. (type of genus) and B. tuberculus sp. nov.; Petasopsis gen nov. erected for P. brevitarsis sp. nov.; Coelostomopsis gen. nov. erected for C. picea sp, nov. (type of genus) and C. major sp. nov.; Ercycodes gen. nov. erected for Cercyon fossum Blackburn (type of genus) and E. tasrnanicus sp. nov., Cetiocyon gen. nov. erected for Cercyon papuensis Orchymont (type of genus) and C. goliathus Hujibregts; Pilocnema gen. nov, erected for P. maculiapex sp. nov. (type of genus) and P. nigra sp. nov.; Australocyon gen. nov. erected for A. nanus sp. nov., A. flavolineatus sp, nov., A. variegatus sp. nov. (type of genus), A. eungella sp. nov., A. calderi sp. nov. and A. weiri sp. nov.; Chledocyon gen. nov. erected for C. semiopacus sp. nov. (type of genus), C. venustus sp. nov., C. intermedius sp. nov., C. marmoratus sp. nov. and C. queenslandicus sp. nov.; Pseudoosternum gen. nov. erected for P. maculaturn sp. nov. (type of genus) and P. brunneum sp. nov.; Ceronocyton gen. nov. erected for C. obscurum sp. nov. (type of genus), C. affine sp. nov. and C. simile sp. nov.; Cenebriophilus gen. nov. erected for C. costatus sp. nov. (type of genus) and C. subcostatus sp. nov. Cercyon kingense Blackburn is transferred to Cercyodes Broun.

The genera Eurygrnus, Borborophorus and Petasopsis are placed in the tribe Rygmodini, Coelostornopsis in Sphaeridiini, and the remainder of the genera in Cercyonini.

The genera Cercyodes Broun and Notocercyon Blackburn are redescribed.

Notes are given on the other genera of Sphaeridiinae occurring in Australia, and the following genera are recorded for the first time from this continent: Cercyodes Broun, Cryptopleurum Mulsant, Pachysternum Motschulsky, Mircogioton Orchymont, Psalitrus Orchymont, Paromicrus Scott and Noteropagus Orchymont.

A key to all genera occurring in Australia, as well as notes on their ecology, is given. The Australian distributions of all species of the new genera are mapped.

Lectotypes are designated for Cercyon fossum Blackburn, 1888 and C. kingense Blackburn, 1907.

The basal phylogeny of the Sphaeridiinae is briefly discussed, and the distributional patterns of the Australian genera are summarised.