Insecticidal formulation based on essential oil from Ocimum basilicum Linn. Herb supported onto modified kaolinite for stored maize protection

Abstract

In this study, essential oil was obtained by hydrodistillation from the leaves of Ocimum basilicum and it was analyzed by GC-MS. Eucalyptol (11.19 %), trans-iso eugenol (13.12 %), hexadecanoic acid methyl ester (19.26 %) and 9-octadecenoic acid (z)-methyl ester (25.12 %) had been the leading four main components of the plant leaves of the essential oil. The unmodified and modified kaolin was characterized and analyzed by XRD, FT-IR, TGA and SEM/EDX and thus the principal mineral of the nanoclay was proved to be kaolinite. The hydrodistiled essential oil in the absence of the clay support was evaluated within 24 h of exposure time and the outcome revealed that it was insecticidally active against the maize weevil, S. zeamais adults. Moreover, the exposure time effect, the formulation efficiency, the effect of remnant and stability of the prepared formulations were investigated and the results indicated an enhancement of bioinsecticides for a long period with upgraded persistence against the S. zeamais. Finally, the results recommend that O. basilicum essential oil - modified kaolinite formulations should be used as best options to chemical insecticides in pest control of stored products like stored maize grain insects, S. Zeamais.

Keywords

• Ocimum basilicum
• Essential oil
• Modified kaolinite clay
• Insecticidal formulation
• Control released
• Sitophilus zeamais