This looks like a job for DDT. It would get the beetles and the stop the incoming plague of Malaria and Dengue Fever that is forthcoming.
—nope—there is something like 100 million acres that would have to be done , tree by tree-—largely , Ma Nature (or Gaia) are gonna take care of this—
Won't work. Once the beetles are in the tree they can't be killed. They have to be killed in the pupae stage when they move to healthy trees. Tree bands work best, but it's impossible to band an forrest. The next best think is harvesting the trees and stopping the spread by creating a buffer zone wider than they are able to migrate.