Submitted to: Small Fruits Variety Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 18, 2002
Publication Date: January 2, 2004
Citation: Sampson, B.J., Cane, J.H., Stringer, S.J., Spiers, J.M. 2004. Screenhouse Evaluations of a Mason Bee Osmia ribifloris (Hymenoptera: Megachilidae) as a Pollinator for Blueberries in the Southeastern United States. Small Fruits Variety Journal. 3(15):381-392. Interpretive Summary: Osmia ribifloris is a docile, wild bee that is being domesticated as a commercial blueberry pollinator. Larvae and pupae of this bee develop normally in Mississippi, and adults can forage under weather conditions considered to be less clement to honey bees. Osmia ribifloris was an efficient blueberry pollinator, as fruit were set by two-thirds of the flowers visited by the bee. Without any bee visitation t flowers, southern blueberries set no fruit. It was estimated that the lifetime pollination efforts of one healthy O. ribifloris female will contribute to the production of 12 to 24 dollars worth of fresh blueberries.
Technical Abstract: Osmia ribifloris Cresson is a solitary stem-nesting bee whose adult emergence perfectly coincided with the flowering periods of cultivated southern blueberries. An isolated case of extended prepupal dormancy occurred, but never reappeared in a captive population raised in Mississippi. Adults foraged from 0700 - 1800 hrs, and flight was initiated at an air temperature as low as 9 deg. C. Females were comparatively slow pollinators visiting about 8 blueberry flowers per minute. 55 ± 7 flowers were visited per pollen trip, and 18 ± 2 pollen trips were necessary to fully provision a nest cell. 1,400,000 ± 160,000 tetrads constituted a full blueberry pollen provision. Despite a lack of floral sonication, O. ribifloris was an efficient blueberry pollinator with rabbiteye blueberry flowers setting 33 - 67% seeded fruits.