What to do with a rude co-worker that is senior to you?

The best thing to do is to talk to his supervisor and let him know how you feel. It seems that if you let the Senior yst person know he will get worse he probably will not lay off. If you talk to his supervisor in a professional matter and letting him know that its nothing personal and that you feel like you are being micro-managed by this guy and that you don't feel comfortable approaching this guy on your own they should do something about it. Good Luck I have gone through the same thing but luckily management took care of it after a long time and more complaints were filed.