Large Wasps on Lilac: Hornets, Moths, or Cicada Killers?

South Jersey lilac attracts 1.5″ wasps post-bloom. What are they? Harming plant? How to remove?

Three Likely IDs

1. Giant Hornet (European hornet)
2. Hummingbird Moth (day-flying, hovers)
3. Cicada Killer (large, digs burrows)

Google images to match. Most are beneficial or neutral.