lanternfly, ailanthus, tree of heaven
Just watched MPT's Farm & Harvest episode that featured lanternfly invasion. It was suggested we 1) be visually vigilent, and 2) remove any ailanthus which is a favorite host. Since ailanthus is a weed tree with no known benefit, why wouldn't they be preserved in monitored areas as natural traps to facilitate eradicating colonies? Am assuming that albeit a preferred host, if not available, the lanternfly will just go to other plants.
Good deduction, and yes, this is being done. While ailanthus will be used as a trap tree in some situations, the vast majority of homeowners will not be willing or able to monitor and kill the spotted lanternfly on their ailanthus. For that reason, homeowners are encouraged to remove them.
Much is still not known about spotted lanternfly and a great deal of research is ongoing. They are so strongly attracted to ailanthus that there is speculation that it is critical in their life cycle, so removing it weakens them.