I don't think even the authorities know which of their efforts are most effective. Their numbers do seem to be declining in some places, which is heartening at least.
As far as I know, the authorities have done... nothing? I don't know that I would want them to do anything either, I suspect like stink bugs before them, they will enjoy a season or 2 of rapid population growth followed by a decreased population in subsequent years as they acclimate to their new environment.