Nanostructured lipid carrier of oregano essential oil for controlling Tuta absoluta with minimal impact on beneficial organisms

Tuta absoluta is a significant invasive pest, severely impacting the global tomato industry. Prolonged application of chemical insecticides has led to varying degrees of resistance in T. absoluta populations. Additionally, chemical insecticides are causing serious threats to the environment. Aiming to develop a novel bioinsecticide based on Origanum vulgare essential oil (OVE) against T. absoluta, we carried out its nanostructured lipid carrier formulation (OVE-NLC). The obtained OVE-NLC had spherical particles approximately 94.26 nm in size with a uniform size distribution of less than 0.3 and a zeta potential of - 18.75 mV. The formulated NLC also had encapsulation efficiency up to 96% and was stable at 25 °C for 3 months. The FTIR results indicated no significant chemical interaction between EO and NLC components. OVE-NLC demonstrated significant toxicity towards T. absoluta larvae and a remarkable oviposition deterrence for females. The nanoformulation also negatively affected the population growth parameters of T. absoluta, significantly reducing its fecundity by approximately 70% and 42% in contact and topical assays, respectively. Additionally, OVE-NLC had no lethal effects on the generalist predator Macrolophus pygmaeus and pollinator bee Bombus terrestris as non-target organisms. Results suggested that OVE-NLC could be successfully used as a potential tool for tomato integrated pest management programs.