Abstract: In this study, variations in idiosomal setae length and genetic similarity using RAPD-PCR technique were evaluated in Oligonychus punicae (Hirst) or Oligonychus biharensis (Hirst) (Acari, Tetranychidae) females collected on grapevines or mango trees growing in Tarabana and El Tocuyo counties, Lara state, Venezuela. Idiosomal seta analysis (v2, sc1, sc2, c1, c2, c3, d1, d2, e1, e2, f1, f2, h3) showed significant differences in sc1 and sc2 in O. punicae from both localities, meanwhile in O. biharensis setae v2, sc1, c1, d1, e1 and f1 were found to be different in same localities. The Component Principal Analysis (ACP) on idiosomal setae showed that O. punicae population from Tarabana (TARVID) is similar to those from El Tocuyo (TOCVID). Meanwhile, O. biharensis populations exhibit higher variability in idiosomal setae length than O. punicae populations. Genetic analysis, DNA amplification by RAPD yielded 218 bands, being 175 (80%) polymorphic and 43 (20%) monomorphic. Higher number of bands was obtained with primer OPB10, suggesting it would be able to detect higher polymorphism in individuals studied.