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United States Department of Agriculture

Agricultural Research Service

Research Strategy
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The overall goal of this Research Unit is to ensure the productivity and profitability of insect-pollinated crops by improving the diversity and availability of pollinators for U.S. agriculture.  In general terms, we wish to create a toolbox of pollinators for agriculture.  To accomplish this, we seek to understand the diversity and abundance of wild bees in the U.S., and to develop methods for managing a selection of bees as pollinators, including developing effective mass production, release and disease control methods.   Fig. 1 is a conceptual model of the overall structure of our research.  However, to attain our objectives, we plan to focus on specific ecological or agricultural systems.

Fig 1.  Research objectives (bold rectangles) and expected outcomes (ovals).  PIRU is studying the current diversity and biology of pollinating bees in the U.S. Taxonomic and ecological knowledge of bees can be used to sustain native, wild pollinators.  This knowledge is also required for selecting and developing new species of bees as managed pollinators.  Thus, our research can improve the protection of native bees, but also supply information for developing future crop pollinators.  Previous research in these areas has already led to the development of some non-Apis bee management techniques, and we are simultaneously pursuing the improvement of these techniques and developing disease control strategies for them.   As a result, we work to improve pollination in conventional cropping systems and assist in the development of new crops or new cropping systems with specialized pollination needs.

The Need For This Research

Pollination is an ecosystem function that is vital to U.S. agriculture and to the maintenance of our wild lands.  Reproduction in many wild plants, and the commercial production of more than 90 crops, including almond, apple, cherry, cranberry, blueberry and squash, as well as numerous seed crops, are accomplished through bee pollination.  The honey bee Apis melliferais our most common agricultural pollinator, and farmers rent more than two million colonies every year for pollination.  However, honey bees are not native to North America, so they are not adequate pollinators for many native plants.  Furthermore, honey bees are threatened by a myriad of problems that seem to be increasing in severity, making them less economical to manage than they once were.  Recently, beekeepers have faced a crisis known as Colony Collapse Disorder (CCD).  Significant scientific time and effort has been put into identifying what CCD is, but as time goes on and no one cause surfaces, we begin to conclude that CCD is actually a combination of several factors and has no simple solution.  Fortunately, honey bees are not the only bee species that make for good crop pollinators; both solitary bees and bumble bees have long been considered for commercial production.  In addition, some crops are more reliably pollinated by non-Apis bees (e.g., alfalfa seed, tomatoes, blueberries, sunflowers, and crops grown in greenhouses and under row covers).

However, of the approximately 3600 bee species that occur in the U.S., only a few are managed commercially as crop pollinators.  These include a bumble bee (Bombus impatiens), the alfalfa leafcutting bee (Megachile rotundata), a few species of Osmia bees (the blue orchard bee Osmia lignaria, the horned-faced bee Osmia cornifrons, and a raspberry bee Osmia aglaia), and the alkali bee (Nomia melanderi).  PIRU has developed ways to manage some of these bees, much the same way that we already manage honey bees, with the goal of providing farmers an array of different pollinators, and reducing pressure on honey beekeepers to move their bees long distances in an attempt to meet every pollination demand.  In particular, our research is needed to avoid having the fate of the honey bee fall on other bees, each of which have their own diseases and parasites and are susceptible to environmental residues of pesticides and loss of habitat.  Research is needed to mitigate the negative impacts of these factors, and to make these bees truly domesticated.  In addition, many species of wild bees provide a free pollination service for agricultural crops, and as stated above, maintain plant reproduction in our wild lands.

Our ultimate goal is to integrate fundamental and applied research efforts to improve the health and sustainability of our nation's pollinators, thereby contributing to the vitality of the U.S. agricultural sector that depends on bee pollination, and to the vitality of wild lands wildlands.


Last Modified: 4/8/2009
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