In natura and nanoencapsulated essential oils from Xylopia aromatica reduce oviposition of Bemisia tabaci in Phaseolus vulgaris

Bemisia tabaci is an agricultural pest of worldwide distribution that causes serious damage to several crops. It is of crucial importance to control this pest, especially for large-scale production. Accordingly, formulations based on essential oils of pesticidal action are potentially promising in the agricultural sector. Additionally, the nanoencapsulation of these bioactive compounds promotes their protection from environmental degradation and prolongs their biological activity. Here, we develop PCL (poly-epsilon-caprolactone) nanoparticles containing essential oils of Xylopia aromatica leaves and fruits and evaluate their insecticidal effect in B. tabaci Middle East Asia Minor 1 biotype B. The average yields of essential oils from leaves and fruits of X. aromatica were 0.05 and 0.80%, respectively. The major compounds in the essential oil of leaves were bicyclogermacrene (44.80%), alpha-pinene (8.23%) and beta-pinene (7.75%) while in fruits were alpha-pinene (35.40%), beta-phellandrene (31.05%) and beta-pinene (22.51%). The PCL nanoparticles containing the essential oils exhibited encapsulation efficiency of 95% and particle diameter smaller than 500 nm. Biodegradable nanospheres substantially protected the essential oils from accelerated degradation caused by UV light and also prevented possible phytotoxic activity of the in natura essential oil from leaves of X. aromatica in high concentrations, probably due to the gradual release. In natura and nanoencapsulated essential oils from leaves and fruits decreased (up to 98%) the oviposition of B. tabaci in common bean leaves. Our results indicate that both in natura and nanoencapsulated oils of X. aromatica may potentially be used as alternative to the chemical control of B. tabaci. Graphic abstract