Four plant oils at the concentrations of 2.5, 5 and 10% viz.; Jatropha, (Jatropha curcas) Ocimum, (Ocimum grattisimum) Kapoor, (Cinnamomum camphora) Lantana, (Lantana camara) were tested for the growth regulatory activities against 8 day old larvae of S. litura and S. obliqua larvae and plant oil composition testing by GC-MS analysis for selected oils. Among four oils J. curcas (10%) showed better results for both the insects while least effective were L. camara (2.5%) and C. camphora (2.5%) for S. litua and S. obliqua larvae respectively. J. curcas (10%) also showed highest terminal larval mortality followed by C. camphora > O. grattisimum > L camara for mentioned insects. The analysis of plant oils revealed the presence of over 43 compounds, contributed to 99.16, 92.78 and 94.97 % of the total tested oils (J. curcas, O. grattisimum and C. camphora) respectively. In tested oils by GC-MS analysis among other compounds in highest quantity terpenoids were found. These plant secondary metabolites can be the responsible factor for effect of plant oils against insect-pest growth and development or as plant based insecticides.