Nanoinsecticide toxicity of the essential oil of Eucalyptus camaldulensis toward date palm white scale insect Parlatoria blanchardii

Naser Aldosary, Ihab Alnajim, Fatima A. Hasan, Muhammad A. Al-Darwish

Abstract: The date palm white scale insect Parlatoria blanchardii is a serious pest of date palm trees. Traditional chemical pesticides are ineffective as these pests hide under a thick cuticle layer that protects them from insecticides and other control factors. Therefore, the study aimed to formulate nanoemulsion of Eucalyptus camaldulensis essential oil utilising low energy method to prepare eco-friendly insecticide. One nanoemulsion phase diagram was constructed by employing mineral oil as the oil phase, span 80 and tween 80 as the non-ionic surfactants, and water. Six points were selected from the phase diagram and mixed with 20% of E. camadulensis leaves and seeds essential oil, which was obtained by hydrodistillation. Two formulations exhibited high stability under centrifuge and storage conditions with good physical characterisations. These formulations were nanoemulsion formulations with particle sizes (65.44 to 54.65 nm). The toxicity of the leaves and seeds essential oil nanoemulsion formulations against P. blanchardii was higher than non-formulated essential oils. The toxicity increased with increasing concentration and exposure time. Depending on these findings, the nanoformulations of E. camadulensis essential oil can present a promising, reliable alternative to conventional pesticides to control P. blanchardii as an eco-friendly insecticide.

Keywords: formulation; mortality; nanoemulsion; Phoenix dactylifera; toxicity

Date published: 2023-10-23