Pesticide Contamination of Bees: Determing the Diversity and Concentration of Compounds found in Hives Located across Ohio Agricultural Landscapes

Our study aims to investigate the role of landscape composition in contaminant exposure by pollinators, specifically the European honey bee (Apis mellifera) and the common eastern bumble bee (Bombus impatiens). By analyzing pesticides found on the worker bees foraging in urban, rural, and suburban landscapes we hope to understand how the Ohio landscapes in which these bees forage influence their likelihood of contamination.  Both analyses of pesticide types/concentrations found in bees and landscape analyses are ongoing. Bumble bee samples were found to be unresponsive to pesticide analysis, and to ensure use of these samples we are investigating additional contaminants, heavy metals. Preliminary results show bumble bees are exposed to a variety of heavy metals in rural, suburban, and urban environments.  Workers exhibited significantly less levels of cadmium, copper, and lead as distance from the urban center of Cleveland, OH increased. Additionally, levels of cadmium, copper, lead and zinc present in worker bees significantly correlated with decreased larvae present in the colony after three weeks of exposure. Objectives 1 and 2 of our study should be completed in 2016.

Introduction:

Over the last decade pesticide exposure has been cited as a probable factor contributing to global bee decline (Goulson et al. 2008). In fact, neonicitinoid pesticides such as imidacloprid have been banned from use in Europe starting in 2013 due to concern over their negative impacts on honey bees, particularly their role in Colony Collapse Disorder, or CCD (McDonald-Wilson 2013, Schmuck et al. 2001). However, while there has been some evidence of pesticide exposure incurred by honey bee hives of large-scale beekeeping operations, there is as yet virtually no evidence that the risks are similar for smaller-scale operations like those often providing honey bee hives to fruit and vegetable growers in the north central region (Mullin et al 2010). Additionally, there has been no evidence as to what pesticides bumble bees and other bees native to Ohio are exposed to in their natural foraging environments. These native pollinators provide significant pollination to fruit and vegetable crops as well as non-crop plants, contributing the majority of pollination services in some systems (Greenleaf et al. 2007). Ohio produces vegetable and fruit crops valued at over 135.4 and 45.4 million dollars per year, respectively, which benefit from pollination services rendered by managed and non-managed bees alike (NASS 2007).Our study will be the first to detail the types and concentrations of pesticides encountered by foraging honey bees from small-scale beekeeping operations, as well as the first to document the pesticides encountered by foraging bumble bees of any species worldwide. We will also conduct the first investigation into landscape composition as a predictor of pesticide exposure. In doing so, this research will not only prove invaluable to the sustainable pollination of crops in Ohio and the north central region by identifying risks to pollinator health and function, but it will also investigate a possible mechanism influencing these risks. This study will contribute to NCR-SARE’s broad-based goals by providing beekeepers, fruit and vegetable growers, and extension agents with information regarding the effects of pesticide management practices on pollinators. This information will prove useful in encouraging best management practices and enhancing environmental quality in agroecosystems.