The “weak-veined” Lasioglossum in Australia, New Zealand and West New Guinea, with descriptions of three new subgenera (Hymenoptera: Apoidea: Halictidae)

Currently, all Australian and New Zealand weak-veined Lasioglossum Curtis 1883 species are placed in the subgenus Austrevylaeus Michener 1965 which has L. sordidum (Smith 1853), a New Zealand species, as the type species. A comparative analysis was conducted for Austrevylaeus against three Northern Hemisphere weak-veined subgenera Evylaeus Robertson 1902b, Hemihalictus Cockerell 1897 and Sphecodogastra Ashmead 1899. This resulted in a reclassification of the Australian weak-veined Lasioglossum fauna with three new subgenera erected: Cnephalictus new subgenus, Enigmalictus new subgenus and Evyloides new subgenus and Austrevylaeus is now restricted to the New Zealand species. Diagnoses are provided for the Australian and New Zealand weak-veined subgenera. All Australian species are described, in some cases with one sex for the first time. In addition, citation lists, type designations, type depositories, synonymy lists, diagnoses, distribution maps, SEMs of female inner metatibial spurs, montage images (specimen and male genitalia), examined material, etymologies of species names and comments on taxonomy and floral visitations are presented. Keys to both sexes for Australian and New Zealand species are provided. The New Zealand weak-veined Lasioglossum fauna contains three species: subgenus AustrevylaeusL. mataroa Donovan 2007, L. maunga Donovan 2007 and L. sordidum. The Australian weak-veined Lasioglossum fauna contains 11 species. Valid, new taxa and new synonyms include: subgenus CnephalictusL. amber new species, L. bernhardti new species, L. contaminatum (Cockerell 1910a) and L. lorienae new species; subgenus EnigmalictusL. blighi (Cockerell 1915) (junior subjective synonym is Halictus pertasmaniae Rayment 1953 new synonymy), L. disclusum (Cockerell 1914) (junior subjective synonym is H. pertribuarius Rayment 1935 new synonymy), L. excelsum new species, L. exoneuroides (Rayment 1953) (junior subjective synonym is H. portlandensis Rayment 1953 new synonymy), L. melanurus (Cockerell 1919) and L. rufibasis (Cockerell 1923); subgenus EvyloidesL. ewarti (Cockerell 1910a). A re-evaluation of the number of subgenera and species included in the world-wide Lasioglossum strong-veined and weak-veined series is presented. Examination of specimens in the Bishop Museum revealed the first known specimen and new species of a weak-veined Lasioglossum from West Papua (Indonesia) with an elongated head lengthL. oblongulum new species. The head elongation and subgeneric placement of this species are discussed.