Biological control of varroa with entomopathogenic fungi : a sustainable solution for a globally important pest?

There is a very worrying decline in the number of colonies of the Western honeybee, Apis mellifera, in the northern hemisphere. This comes at a time when the worldwide demand for crops pollinated by bees and other insects is increasing as never before. While no single factor accounts for the loss of all colonies over the world, there is now overwhelming scientific evidence that the varroa mite, Va Varroa destructor, is the primary cause for bee decline in Europe and is a key participant in bee declines in North America. Why is varroa is such a problem and is there a micro biologically based opinion for its management