The flower it's visiting is Aster novae-angliae 'Chilly Winds', a selection of the native New England Aster from Seneca Hills Perennials in upstate New York. This plant has been a pollinator magnet in my backyard native plant garden for weeks. It's massive and overgrown and poorly placed, crowding out everything else around it. I'll have to find it another place for next year.
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Seneca Hills Perennials