A revision of the Australian leafcutter bees, previously placed in Megachile (Eutricharaea) (Hymenoptera: Megachilidae), with descriptions of seven new species

The species in the subgenus Eutricharaea Thompson, 1872 (genus Megachile) construct brood cells from pieces of leaves or petals cut from a diverse array of plants. Commonly bees in this group are called ’leafcutter bees’. The Australian species, as previously placed in Eutricharaea, are revised and redescribed, and seven additional species are described. New combinations are proposed for two species: Chalicodoma (Hackeriapis) atrella Cockerell 1906, comb. nov. = Megachile (unplaced) atrella Cockerell 1906; Megachile (Eutricharaea) hampsoni Cockerell 1906, comb. nov.= Megachile (unplaced) hampsoni Cockerell 1906. Based on examination of type specimens the following 12 names were synonymized: Megachile adelaidae Cockerell 1910a, syn. nov. = Megachile (unplaced) atrella Cockerell 1906; Megachile phenacopyga Cockerell 1910a, syn. nov. = Megachile (Notochile) chrysopyga Smith 1853; Megachile australasiae Dalla Torre 1896, syn. nov., and Megachile cygnorum Cockerell 1906. syn. nov. = Megachile (Notochile) macularis Dalla Torre 1896; Megachile austeni Cockerell 1906, syn. nov., and Megachile rowlandi Cockerell 1930a, syn. nov. = Megachile (unplaced) pictiventris Smith 1879; Megachile ignescens Cockerell 1929, syn. nov. = Megachile (Aethomegachile) rhodogastra Cockerell 1910; Megachile cetera Cockerell 1912, syn. nov., and Megachile subserricauda Rayment 1939, syn. nov. = Megachile (Eutricharaea s. l.) serricauda Cockerell 1910c; Megachile ciliatipes Cockerell 1921, syn. nov., Megachile detersa Cockerell 1910b, syn. nov., and Megachile quinquelineata Cockerell 1906 = Megachile (Anodonteutricharaea) simplex Smith 1853. Phylogenetic analyses of DNA barcode data indicate that the Australian leafcutter bees, as previously placed in subgenus Eutricharaea, are not monophyletic and some are associated with other Megachile subgenera that also occur in South-East Asia. A description of a new subgenus Megachile (Notochile) that contains a clade of Australian endemic species is provided, and most species have been transferred to other subgenera. All descriptions in this paper are accompanied by high resolution diagnostic images and distribution maps. Data on flower visitation and phenology are given. Dichotomous keys to both sexes of the species are provided.