Hi, Jen! Welcome to NGA.
Speaking of "gall", that exterminator has plenty already. By any chance do you live on Cape Cod? We used to call them "Cape Cod Craftsmen", since that sounds better than "lazy, lying #$##^###!!! liars" .
Or maybe he just doesn't know the difference between a leaf and a bug, or a mite and a termite.
Maybe he thinks a "ter-mite" is one kind of mite!
I'm going to put my bet down on "lying #$##^###!!! liar" !
Good luck with your maple tree!
"Maple leaf galls seldom, if ever, cause permanent injury to a tree, but they do detract from the beauty of the leaves."