Title: The oligolectic bee Osmia brevis sonicates Penstemon flowers for pollen: a newly documented behavior for the Megachilidae Author
Submitted to: Apidologie
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 2, 2014
Publication Date: N/A
Interpretive Summary: Bees are unique among pollinating insects for their ability to sonicate or buzz flowers to release pollen that is shed through terminal pores or slits in the anthers, akin to a salt shaker. Bumblebees are the most familiar buzz-pollinators, which has great commercial value in the production of greenhouse tomatoes. The bee family Megachilidae has the more agriculturally managed non-social bees than any bee family (e.g. alfalfa leaf-cutting bee, blue orchard bee), but until now, its species were thought incapable of sonicating flowers. The megachilid bee Osmia brevis was recorded as it audibly buzzed anthers of two of its floral pollen hosts, Penstemon radicosus and P. cyananthus. The high-pitched sonication sequences of this penstemon specialist are readily distinguishable from both its flight sounds and a second foraging behavior, anther rasping, but resemble the familiar sonication sounds of bumblebees buzzing P. strictus flowers.
Technical Abstract: Flowers with poricidally dehiscent anthers are avidly visited and often solely pollinated by diverse bees capable of buzzing the flowers to harvest their pollen. Sonication results from shivering of the thoracic flight muscles. Honey bees (Apis) and the 4000+ species of Megachilidae are enigmatic in their seeming inability to sonicate flowers. The oligolectic megachilid bee Osmia brevis was found audibly sonicating two of its floral pollen hosts, Penstemon radicosus and P. cyananthus. The bees’ high-pitched sonication sequences are readily distinguishable from flight sounds in audiospectrographs, and are shown to resemble the familiar sonication sounds of bumblebees buzzing P. strictus flowers.