Imidacloprid, potatoes, and honey bees in Atlantic Canada: is there a connection?

In 2000, some beekeepers in Prince Edward Island (PEI), Canada, experienced substantial, unexplainable honey bee colony losses. Prince Edward Island is an Atlantic Canadian province of approximately 5,684 km super(2) with about 261,482 hectares (46%) of its land base involved in agriculture, and about 135,600 hectares of this agricultural land is in rotation with potato crops (extrapolated from PEI Agricultural Statistics for 1999). About 90% of the potato crop is treated with imidacloprid in-furrow. Some beekeepers in France felt that imidacloprid use on sunflower crops was negatively affecting honey bee health in that country. Beekeepers who experienced the high colony mortality on Prince Edward Island wanted this possible connection investigated as well. Their concerns were heard, and as a consequence, a residue study was done in 2001. The results did not show detectable residues of imidacloprid or two of its metabolites in bee forage plants or hive products at the limit of quantification of 2 ppb. Unexplained and substantial honey bee colony losses continue to plaque and mystify some beekeepers around the world. With increasing demand for honey bees for pollination of fruit crops in Atlantic Canada, this problem is a very real concern. Therefore, a comprehensive, mulitfactor investigation was initiated in the spring of 2002. Project planning input was sought from beekeepers, and partnerships with beekeeper associations, producer organizations, individuals, corporations, institutions and governments were developed. The final version of the project includes seven major components which encompass many of the factors that beekeepers agree can negatively impact honey bee health. Also, these factors are in agreement with those listed in a Canadian Association of Professional Apiculturists (CAPA)/Canadian Honey Council (CHC) joint committee recommendation regarding the need for broad, factor based studies. The results of the 2001 investigation, and the methodologies of the 2002/2003 multi-factor study are presented.