Wasps

While this is interesting (and long-expected), I can't help but feel that there may be a small bit of confusion with the really problematic Asian hornet, Vespa mandarinia. That's the one that's really dangerous to honey bee stocks, as a few of them will kill off an entire hive of European bees, who don't have the heat-smothering defence mechanism that native Japanese bees have. Fortunately, they haven't been found in Europe yet.

I don't think Vespa velutina does anything that European hornets don't do (e.g., ambushing honeybees), but their rate of reproduction may be the main problem. I'll have to do some more reading on that, though.