God of the Philistines in the Old Testament whose name translates as lord of flies (9)
I believe the answer is:
beelzebub
(Other definitions for beelzebub that I've seen before include "devilish beast" , "Tempter of mankind; master of Hell" , "God of the Philistines - the Devil" , "Old Nick" , "A devil, 'Lord of the Flies'" .)