Ysachron pilosus gen. et sp. nov. is described from the Caribbean region of Colombia, and an updated key to genera of South American Achrysonini is provided. Moreover, the geographical distribution of 45 species of Cerambycidae, belonging to the subfamilies Cerambycinae, Lamiinae and Prioninae, is expanded, including nine new country records for Colombia and a further locality in Colombia for nine species.