It looks like it is an invasive species. This definition says it was introduced:
http://en.wikipedia.org/wiki/Varroa_destructor
Reducing the size of the wax foundations' cells sounds more logical than chemically treating a colony, as the mites build up a resistance and the honey may not be fit for human consumption. Coating the bees with powdered sugar sounds good though probably not perfect.
With smaller cells the bees will be smaller, and the honey/pollen production will be less. Italians are nice and big, good housekeepers, too.
You're talking big money if purchasing new queens to introduce and force swarming. For every swarm, you'll need more woodenware, frames.
Egad! don't get me started talking about beekeeping ....