Abstract : The black beans Aphid, Aphis fabae L. are very important pest species of many greenhouses and field plants in the world which causes damages through feeding on sap and transmitting viral diseases. In this research, the essential oils of medicinal plants: Myrtus communis L. (Myrtaceae) and Rosmarinus officinalis L. (Lamiaceae) were investigated for their fumigant toxicity and repellent activity against Aphis fabae L., under laboratory conditions. The LC50 values indicated that Rosmarinus officinalis L. oil exhibited higher toxicity with LC50 of 1.14 µL/cm³, whereas Myrtus communis L. showed LC50 of 2.31 µL/cm³. The chemical composition of the essential oils was analyzed using GC-MS, revealing a diverse array of chemical compounds that constitute the essence of each oil. Basil essential oil contains α-pinene, 1,8-cineole, α-terpinol, and linalool, while rosemary oil consists of 1,8-cineole, β-pinene, D-camphor, and camphene. Sensitivity tests were conducted under laboratory conditions against the black bean aphid, showing that this biological activity is primarily due to the richness of these oils in terpene compounds known for their effectiveness against pests. The results obtained from this study indicate that essential oils have significant potential for use in agriculture against Aphis fabae L., as an alternative to chemical pesticides for pest control in the near future.