The Locust Emblem is a Collectible in Gears of War 2 and is the equivalent of the Coalition of Ordered Governments COG Tags. It is believed that the Locust may keep track of their soldiers in the same manner that the COG does.
COG Intel reportEdit
Do the Locust have their own version of COG tags?
I just found an iron pendant attached to a silver chain, so either they keep track of their soldiers in a similar way that we do... or they just have really bad taste in jewelery.
My guess is the latter.