Global warming isn't helping things either. Lots of pests that used to stay down south are marching north as the years warm.
Frost would typically kill a lot of species, except a few that are specialized to withstand it. Withstanding frost is often a trade-off. So if this threat is removed, many native species have a disadvantage.
(I'm beekeeper and many of the threats to native honeybees are because (European) honeybees put a lot of energy into preparation for long periods of frost,while their adversaries don't do that. It's a bit like the story of the Ant and the Grasshopper. Only now it turns out the grasshopper was right all along, in not caring)
the pine beetle in particular is problematic because it will swarm and kill tons and tons of pine trees -- which is fodder for massive forest fires.
I've never seen its kind before, and I've lived all over Canada. And yes, it wasn't a one-off, I've seen many, and a friend commented on the same.
I imagine it is invasive. Bah.