If this weren't obviously a serious post I would have bet money that a "winter moth" in New England was a myth or a practical joke or put-on. How low of a temperature will they be active in? Can you literally have snow on the ground and moths buzzing around porch lights?

No Joke. As I understand it, yes, there can be snow on the ground and Winter Moths in the air. You can search around on Google for "Winter Moths" for more info, but the UMass link below is not too far from me. -Glenn

Here is a link that might be useful: UMass Winter Moths

Here (Montana) we occassionally see "snow flies", which apparently need only a little sunlight to emerge, and then do whatever it is they do until it gets cold again. Fly fishermen will try to fish a snowfly hatch from time to time, but it's hard if the air temperature isn't consistently above freezing, as the wet fly line freezes up! But these are very small, almost midges. I'm not aware of any bugs that bother fruit trees in the winter. I've seen spiders walking on snow- go figure.

Yeah, from what I've read, Winter Moth is active from late Nov through and all of Dec. It will lay it's eggs during this time in the bark of trees, under the branches, etc. It's later, when the very small caterpillars emerge that they do the damage to the buds. Apparently, it's quite easy for them to wipe out a whole crop of blueberries, and apple trees are another favorite. From the responses so far, it doesn't seem like there's a lot of first hand experience with these buggers, so I'll probably just stick with the dormant oil for now and cross my fingers. Thanks again,
-Glenn

I'd stand astounded if I ran into a bunch of flying bugs with the temperatures at or below freezing and had been for a month. I don't know why though; high-latitude cold-blooded fish can swim around just fine in 28 degree water.