Another post about bees and pesticides.
It's very much you can't have it both ways. Bees pollinate rape seed crops but the agrochemical industry wants farmers to use pesticides that even they do not directly kill bees, appear to be fatal for honeybee colonies.
Check out the article in the Guardian;
http://www.theguardian.com/environment/2015/aug/20/pesticides-neonicotinoids-linked-bee-decline-first-time-large-scale-field-study?CMP=Share_AndroidApp_Outlook