 Bumblebees are parasitised by tracheal mites , Locustacarus buchneri ; protozoans including Crithidia bombi and Apicystis bombi ; and microsporidians including Nosema bombi and Nosema ceranae . The tree bumblebee B. hypnorum has spread into the United Kingdom despite hosting high levels of a nematode that normally interferes with queen bees ' attempts to establish colonies . Deformed wing virus has been found to affect 11 % of bumblebees in Great Britain . 
