Just as a general disclaimer, note that I am proposing Ice / Bug and not Bug / Ice. I don't think there is any precedent for types flipping upon evolution in game, but perhaps I am wrong on that front; lemme know if I'm wrong. I know it's super nit picky, but just making sure you all are aware!
While Ice / Bug is the obvious choice, I think there could be a strong case for solely Bug-type as well. The design certainly hints at Ice-typing, but the design doesn't rely heavily on it, in my opinion. For comparison, I think that Shelmet screams Bug / Steel, and yet it is only Bug-type. Perhaps that is because of its unusual evolution method, but the point still stands. Keep up the discussion; I like how this is going.
Also Snover is one of my favorite Pokemon; pwnemon, you monster ;__;