Formulation, characterization, and evaluation of the insecticidal activity of thymus vulgaris oil nanoemulsion against the agricultural pest Aulacophora foveicollis (Red pumpkin beetle) (Chrysomelidae: Coleoptera)
Natural products such as plant essential oils are formulated as nanoemulsion and widely used in the application of insect pest control. Thymus vulgaris, anessential oil has many biological properties naturally. In the present study, using the GC-MS instrumentation the major chemical components of the thyme oil were identified. The chemical component, thymol was identified with the highest peak area of 15.65%. The O/W nanoemulsion was then formulated using the following components such as oil, surfactant, acetone and distilled water by ultrasonication method. The formulated nanoemulsion was investigated for the stability study and the stable nanoemulsion was characterized by DLS method with the mean droplet diameter of 12.81nm, PDI was 0.13 and zeta potential +59.4 mV values, everything together proves to have a good stability of the formulated emulsion and the mean pH value were also found to be 5.43 using pH meter. The nanoemulsion and the bulk emulsion were screened against the adult beetle, Aulacophora foveicollis to assess the insecticidal activity at different concentrations. The nanoemulsion has shown the higher insecticidal activity when compared to the bulk emulsion with an effective LC50 value 73.3% in nanoemulsion and 29.9% in bulk emulsion respectively. Therefore, from our study it could be concluded that nanoemulsion may be used as an effective agent against the agricultural pest Aulacophora foveicollis and also alternative for synthetic chemicals for sustainability of environment.
Farhath Matheen, Kalaiyarasi Lingam, Ananthi Rachel Livingstone. Formulation, characterization, and evaluation of the insecticidal activity of thymus vulgaris oil nanoemulsion against the agricultural pest Aulacophora foveicollis (Red pumpkin beetle) (Chrysomelidae: Coleoptera). International Journal of Entomology Research, Volume 6, Issue 3, 2021, Pages 05-10