Residues in bee-relevant matrices
Application of pesticides during flowering of crops can result in exposure of pollinating insects such as honey bees, bumble bees and wild bees. In addition, residues of pesticides in bee products like honey may result from such applications. One of the overall goals of the German "FitBee" project was to determine the transport of plant protection products into the honey bee colony via individual bees and reduce the exposure to plant protection products by application technology approaches. One of these application technologies is DroplegUL, with which row crops can be sprayed underneath the canopy level, avoiding spray onto the blossoms. In the scope of the "FitBee" project (2011 to 2015), we conducted during five years semi-field experiments in Germany comparing conventional and DroplegUL spraying techniques regarding their implications to honeybee colony exposure. In this context, various trials were conducted in which residues in in-hive matrices (stored nectar, pollen) of bee colonies foraging on a model crop (oilseed rape) which was pesticide-treated with DroplegUL vs. conventional technology were measured.