Acknowledgements
We are grateful to all collaborators who provided specimens for this
study. We would also like to thank Silas Bossert, Gideon Pisanty, Robert
Paxton, Daniel Frei and Beatrice Frey for there valuable repective
contribution in regards to bioinformatic, laboratory and statictical
aspects of this study. This work was mainly funded by the Swiss Federal
Office for Agriculture (FOAG); the sampling of bees was funded by the
Swiss Federal Office for Environment (FOEN).