Disparate continental scale patterns in floral host breadth of Australian colletid bees (Colletidae: Hymenoptera)

Abstract Plant-bee networks are rarely, if ever, studied quantitatively at continental scales, yet these have the potential to inform how biota and ecosystems assembled beyond narrower regional biomes. The short-tongued bee family Colletidae comprises major component of diversity in Australia, with three key subfamilies: Neopasiphaeinae, Hylaeinae, Euryglossinae. We use museum data (> 27,000 records) record binary interactions between bees (from each subfamilies, resolved subgenera) plants (resolved genera). resulting were analysed using bipartite graphs associated indices network structure. subfamilies showed markedly different structures their floral hosts. Euryglossinae had strong Myrtaceae an otherwise relatively narrow host breadth, Neopasiphaeinae little signal specialisation above genera a very broad Hylaeinae appeared intermediate Furthermore, is more speciose within Australia (404 species, or ~ 25% described Australian fauna) than but differences do not correspond stem ages suggesting that time-since-origin does explain species breadth. Patterns breadth persist after rarefaction analyses correct for differing numbers observation records. suggest visitation could be influenced by evolutionary constraints expansion it also possible many bee-plant shaped exploiting traits driven non-bee fauna operating large biogeographical scales.