Modes of honeybees exposure to systemic insecticides: estimated amounts of contaminated pollen and nectar consumed by different categories of bees Agnès Rortais, Gérard Arnold, Marie-Pierre Halm and Frédérique Touffet-BriensApidologie, 36 1 (2005) 71-83DOI: https://doi.org/10.1051/apido:2004071