Efficacies of a bioinsectidde (Xentari), chemical insecticide (PYretbroid), and an I.G.R. (Mimic) and combinations of Xentari and LCID of Baythroid or Mimic were assayed on parasitized and unparasitised larvae of Spodoptera littoralis by Miaoplitis rufiventris. Treated larvae showed lower mortality percentages, higher LCso values and longer LT_so values than the unparasitised ones. Lowest concentration of Xentari (4 x 10⁴ Diamond-back moth Units (OBMU) + LC_io of Baythroid caused 16.67 and 23.33 % mortalities among parasitized and unparasitised larvae, respectively, and the mixture showed potentiative effect. Also, the mbture at 4 x 10⁴ DBMU of Xentari + LC_ao of Mimic led to 30.00 and 33.33 % mortalities, respectively, and showed also potentiative effect.