Notes and keys to the species of Ischnoleomimus Breuning 1940; Malthonea Thomson, 1864 and Mimasyngenes Breuning, 1950 are given. Parablabia Breuning, 1959 is considered a synonym of Malthonea Thomson, 1864, and the following new combinations are made: M. guttata (Kirsch, 1889), comb n. and M. ruficornis Belon, 1903, both transferred from Parablabia. New taxa described: Ischnolea piim sp.n. (Bolívia); lschnoleomimus fovealus sp.n. (Bolívia); Malthonea cumbica sp.n. (Venezuela); Cicuiara gen.n., types pecies Exocentrus striatus Bates, 1866; E. nitidulus Bates, 1866 is transferred to Cicuiara; Mimasyngenes quiuira sp.n. (Brazil, São Paulo); M. icuapara sp.n. (Brasil, São Paulo; Argentina, Misiones); M. ytu sp.n. (Brazil, Minas Gerais and São Paulo). Additional records are provided for; lschnoleomimus excavatus Breuning, 1940; Malthonea guttata (Kirsch, 1889): M. ruficornis Belon, 1903; Cicuiara striata (Bates, 1866); Mimasyngenes lineatipennis Breuning, 1950 and M. inlineatus Breuning, 1956.
Cerambycidae; Desmiphorini; lschnoleomimus; Malthonea; Mimasyngenes