Assessing exposure routes of neonicotinoids to wild pollinators in non-crop systems

In 2012, there was roughly 370 million hectares of farm land in United States (approximately 45% of land area in the US). The top 5 crops in the US (corn, soybean, wheat, cotton, and hay) totaled over 112.5 million harvested hectares and do not directly rely on animal pollinators. However, practices associated with production of these crops (such as the application of neonicotinoid seed treatments) may influence the pollinators in these agroecosystems. The most common commercial pollinator is the European honey bee, Apis mellifera Linnaeus and the effects of neonicotinoids upon this species is well-studied.  However, there is limited information available on the presence of native pollinators, especially in agroecosystems. A pollinator census was conducted during the spring of 2013 in agroecosystems to determine bee diversity and composition. Bee bowls and sweep sampling were deployed at 8 sites in Indiana. The sites were in and around corn fields with managed and unmanaged cover crops as well as alfalfa fields. The agroecosystem was found to be dominated by 9 groups of bees, primarily native, solitary, and ground-nesting: Agapostemon virescens Fabricius, Andrena species, Apis mellifera Linnaeus, Augochlora species, Ceratina species, Eucera species, Halictus species, Lasioglossum species, and Melissodes bimaculata Lepeletier. The results of this census will be paired with the results of an objective quantifying the levels of neonicotinoids found in the flowers of common plants in agroecosystems to identify possible routes of exposure to neonicotinoid insecticides for bees commonly found in agroecosystems.