Affinities between southern Tasmanian plants in native bee visitor profiles

Abstract

Overlap between plants in the bee species visiting their flowers was investigated in three vegetation types near Hobart in southern Tasmania. Visitor profiles of plants were influenced by flowering phenology, the vegetation type in which they occurred, blossom shape and colour, and botanical family. Most Colletidae, especially in the subfamilies Euryglossinae and Hylaeinae, predominantly visited brush-like inflorescences and/or members of Myrtaceae. However, some Colletidae, particularly in the subfamily Colletinae, were oligolectic on non-myrtaceous petaloid flowers. Many Halictidae were polylectic, others foraged predominantly on the yellow zygomorphic flowers of Fabaceae, while others were largely restricted to non- yellow actinomorphic flowers. Both species of Anthophoridae were polylectic, whereas both species of Megachilidae were narrowly polylectic on non-white flowers. It is argued that pollination of nectarless flowers is likely to be enhanced by the presence of petaloid nectariferous flowers, particularly Fabaceae and Leucopogon spp., which provide carbohydrates for their bee pollinators. Mutualism between sequentially, and also possibly concomitantly, flowering nectariferous flowers is also likely via support of shared bee pollinators.