A new species of Compsibidion Thomson, 1864 is described from Piauí. Sydacini, a new tribe of Cerambycinae, is validated. Species of Cerambycidae currently recorded for Piauí (118) and for Ceará (126) are presented. Twenty-two new records for Piauí and eleven for Ceará are reported. Two species are excluded from the fauna of Ceará: Hippopsis lemniscata lemniscata (Fabricius, 1801), and Oncideres saga (Dalman, 1823).
Cerambycidae fauna; Cerambycinae; Lamiinae; Neotropical; Taxonomy
