In the Old Testament famine was always sent by God in areas where they knew God.
(Jeremiah 14:12 NIV) Although they fast, I will not listen to their cry; though they offer burnt offerings and grain offerings, I will not accept them. Instead, I will destroy them with the sword, famine and plague."
I don't know that God causes famines today. But there's nothing in the Bible to suggest that famines were caused by the devil.