 "Trehuaquino" is the demonym for a man from Treguaco, and "Trehuaquina" is a woman from Treguaco.As a commune, Treguaco is a third-level administrative division of Chile administered by a municipal council, headed by an alcalde who is directly elected every four years.For the years 2008-2012, the alcalde is Luis Cuevas Iarra (Ind.