Is this a Robber Fly?
I see that many of the pictures identified as Robber Flies look very different from each other. Some are slender and dark, others look like mutant, Klingon bumblebees. Anyway, this guy really gave me a start when I nearly brushed the leaf he was on with my head. He took off, but was back several times, once with a meal (I don’t mind anyone making meals of the Japanese Beetles.) Is something like this harmless to mammals, or does it have a bite/sting/searing wit/whatever?
This is one of the Bee-Like Robber Flies in the genus Laphria. We are not certain of the species, but there are many pictured on BugGuide. Sadly, too few things in the world are damaging because of their searing wit. Robber Flies do not have stingers, but if handled, we suspect they can bite. They will not attack unprovoked. We wish more predators fed on the invasive exotic Japanese Beetle.