A native ground-nesting bee (Nomia melanderi) sustainably managed to pollinate alfalfa across an intensively agricultural landscapeJames H. Cane
USDA, Bee Biology and Systematics Lab, Utah State University, Logan, Utah 84322-5310, USA
Received 20 June 2007 - Revised 21 December 2007 - Accepted 14 Januay 2008 - Published online 10 April 2008
Abstract - The world's only intensively managed ground-nesting bee, the alkali bee (Nomia melanderi Cockerell), has been used for >50 years as an effective pollinator of alfalfa (Medicago sativa L.) grown for seed in the western USA. Across a 240 km2 watershed in Washington, the 24 most populous of 56 nest sites found were annually surveyed for nesting bees for 8 years. Alkali bees multiplied 9-fold to 17 million females, the largest reported metapopulation of non-social bees. Several sites have remained populous for an unprecedented 50 years. The most populous nesting bed (1.5 ha) grew to 5.3 million nesting females (median = 278 nests/m2), the largest bee nesting aggregation ever recorded. This first-ever exhaustive landscape-level survey for any non-social bee reveals that even amid intensive conventional agriculture, a native bee can sustainably multiply to vast numbers, its nesting aggregations persisting for decades.
Key words: Apiformes / crop / Halictidae / Medicago / pollinator
© INRA, DIB-AGIB, EDP Sciences 2008