how can i get rid of a nest of asian hornet living in a hole inside a tree
Sullivan County Pennsylvania
Are you sure these are asian hornet's? And not european hornets or cicada killer wasps? I don't think the asian hornet has been found in the US yet.
European hornets will nest in tree cavities. Penn State has a fact sheet on these insects at http://ento.psu.edu/extension/factsheets/european-hornet
Control recommendations can be found at: