Importance, Drivers And Conservation Of Wild Bees For Apple Pollination
My dissertation used a multi-disciplinary approach to address the following questions: In the face of global honey bee declines and increasing demands for insect pollination can wild bees ensure adequate pollination? If so, how do we conserve these bees and services? Through pollination experiments in 2010 and bee inventories in 19 central New York orchards in 2011 and 2012, two dominant native bee groups, Andrena subspecies Melandrena and Bombus, were found to be as effective pollinators as honey bees (Apis mellifera L.), per-visit. Pollinator importance across orchards was driven by relative abundance, and was low for native bees compared to honey bees study-wide. The roles of pest management and natural areas surrounding orchards as drivers of wild bee abundance and species richness within 19 surveyed orchards were investigated. Early fungicide and late insecticide applications had strong negative effects on wild bees. Conversely, increasing natural areas in the landscape weakened pesticide effects. Combined increases in chemical inputs and land simplification resulting from agricultural intensification, therefore, pose a risk to wild bees and their pollination services. A holistic approach to balancing costs and benefits of pest management decisions is needed. To inform future wild pollinator conservation and extension to this end, grower perceptions and attitudes of wild pollinators in New York and Pennsylvania were assessed between 2009 and 2012. Growers had high appreciation for wild pollinators, an openness to rely more on naturally occurring bees, and willingness to adopt low-cost, bee-friendly management practices. At the same time, growers reported measurable uncertainty about the effectiveness of alternative pollinators. This uncertainty was the primary obstacle for growers to consider actively managing orchards for wild bees. In sum, wild bees provide important pollination services for the New York apple industry. Wild bee pollination could fill pollination gaps left by declining honey bees, but only where orchards and the surrounding landscape are managed in a manner that supports wild bee abundance. Grower perceptions of wild pollinators are generally positive, but encouraging growers to explicitly integrate wild bees into their pollination strategy requires extension programs that inform growers of wild pollinator efficiencies and provide guidance in implementing pollinator-friendly management practices.
wild bees; crop pollination; apple
Danforth, Bryan Nicholas
Losey, John E.
Raguso, Robert A.; Reissig, William Harvey
Ph. D., Entomology
Doctor of Philosophy
dissertation or thesis