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Survey of soybean insect pollinators: community identification and sampling method analysis

Investigators: Dr. Matthew E. O'Neal and Joe Wheelock

Concerns regarding honey bee (Apis meliffera) declines and pollination losses compelled members of Congress to make the conservation of native bees a priority in the 2008 Farm Bill. Pollination is an essential ecosystem service provided by bees. From native prairie to organic crops, pollination is requisite. Despite the importance of pollination as an ecological process, little is known about the native bee species that mediate pollination services to crops. In response, the Field Crop Entomology Lab has initiated the following project:

Soybean flowers can be a source of nectar and pollen for flower-visiting insects including honey bees (Apis mellifera), native social and solitary bees, and flower flies. Defining the pollinator community can have implications for non-target risks to pollinators as well as the fate of pollen containing specialty traits. Establishing collection methods that effectively trap mobile flower-visitors is vital for obtaining data that accurately represents the abundance and diversity of pollinators in soybean fields. During the 2011 growing season we compared the efficacy of colored bee bowls, yellow sticky cards and sweep netting as trapping methods for bees and flower flies throughout soybean reproductive stages (R1-R6) across four soybean field sites in Iowa. Bee bowls were most effective in trapping the greatest abundance and diversity of bees and flower-visiting flies, collecting a total of 1939 individuals and 33 taxonomic units. Using a subset of the five most abundant female bee species collected during soybean peak bloom, we estimated that 29 percent of the female bees carrying pollen had grains of soybean pollen either alone or intermixed with other types of pollen.

In 2012 we are repeating this study, following the same methodology as in 2011. In addition we will be collaborating with researchers in Ohio and China in an attempt to see how this community differs over space and time. We are also extending this survey to corn in 2012. Bee bowls have been used in corn in previous studies, but the methodology has been inconsistent. We aim to establish a consistent and efficient trapping method for mobile flower visitors throughout corn reproductive stages that will accurately describe the pollinator community.