Hello.  My local bee inspector told me last year that if the varroa mites
and the tracheal mites were not held in check, they would wipe out the
native bees.  The prediction was that if a major breakthrough was not
found the native bees would be wiped out in 5 to 10 years.  It's the
only time I have heard this.  Hope it helps.  Jane Power the powerthatbees