Biological Activity and Field Persistence of Pelargonium graveolens (Geraniales: Geraniaceae) Loaded Solid Lipid Nanoparticles (SLNs) on Phthorimaea operculella (Zeller) (PTM) (Lepidoptera: Gelechiidae)

A new delivery system (was used) to control the potato tuber larvae Phthorimaea operculella (Zeller) (PTM) (Lepidoptera Gelechiidae) based on incorporation of geranium essential oil into solid lipid nanoparticles (SLNs) was prepared using ultrasonic-solvent emulsification technique. EO-SLNs were characterized using Transmission Electron Microscopy (TEM). The results were compared with geranium essential bulk and post loading solid lipid nanoparticles tested in the laboratory and field for their efficiency on larval development, pupal mortality and adult longevity. Laboratory bioassay indicated that geranium essential oil loaded nanoparticles was more effective on both larval and pupal development as well as the adult longevity and female fecundity accordingly the percentage of hatchability. Field-laboratory experiments were conducted to show direct and residual effects of the tested oil free and post loading against the first larval instar of the pest in terms of toxicity and stability. The results indicated that geranium essential oil loaded solid lipid nanoparticles was stable under field conditions and give high percentage of mortality at the two concentrations used. Data presented in this work show greater efficiency of geranium essential oil nanoparticles in controlling Ph. operculella in field.