These are European hornets. I never really thought of them as tree pests before. When I see them on trees, usually they’re feeding on sugar that’s been excreted by aphids or scale insects, or on the alcoholic wetwood flux oozing from a mulberry or a dying elm. But I may be changing my mind a little bit , after what I saw today. Renee, from Audubon, showed me these insects, which she had attempted to identify by searching on the internet. She had noticed them before, but coul