An effective, manageable bee for pollination of Rubus bramble fruits, Osmia aglaia

The non-social cavity-nesting bee Osmia aglaia Sandhouse (Apiformes:
Megachilidae) shows promise as a manageable and effective pollinator for
commercial raspberries and blackberries (Rubus). Floral visits by honey bees (Apis
mellifera L.) or by less numerous caged O. aglaia yielded red raspberries of
equivalent size; berries from unvisited caged flowers were significantly smaller.
Female O. aglaia readily visited flowers of various blackberry cultivars too. Female
foraging behavior on top of a flower’s pistils maximizes the chances for pollen
transfer to innermost stigmas. The bee readily nests in inexpensive commercial foam
nesting substrates modified from those already used for the alfalfa leaf-cutting bee.
An affordable, durable nesting shelter and practical support frame has also been
field tested. Large nesting populations have been increased in commercial bramble
fruits in Oregon USA. Within its range in western Oregon and California USA, this
effective native pollinator of Rubus could be a sustainably managed bee for
cultivated bramble fruits.