Update on Colony Collapse Disease in honey bees

The cause of the decline in European honeybees known as Colony Collapse Disease (CCD) is unclear. Pesticides, mites, viruses and perhaps other chemicals may have contributed to the decline.  In a recent article (Science 351:555, 2016), the authors focus on the host/vector relationship of the honeybee and a mite (Varroa destructor).  The vector mite transmits a virus called deformed wing virus (DMV) to the honeybee that has been clearly linked to colony collapse.  Factors driving CCD that have lead to a reemergence of DMV are thought to include human managed movement of bees, adaptation of this mite to a new host and change in the virus lethality.  Future studies will need to continue to focus on how viruses spread to new hosts and adapt to new environments in light of the importance of the honeybee in pollination of agricultural crops.