Ecological costs of botanical nano-insecticides

Botanical nano-insecticides are a trend in pest control. The natural origin of the active substances, alongside with the methodological approach granted by nanotechnologies are a promising combination of innovation and eco-sustainability, hot topics in the context of ecological transition in agriculture. Nevertheless, their field application is still limited, due to production challenges and risk assessment concerns. Nanoformulations have some advantages over traditional bioinsecticides, including increased bioactivity and persistence, and slow-release rates. Recent research reported promising insecticidal activity of nano-emulsions, micro-emulsions, and nanoparticles loaded with different botanical extracts, oils, and essential oils. Though, despite their proven efficacy against insect pests and vectors, a limited number of studies investigated their safety towards nontarget organisms and fate in the environment. This mini-review provides an overview of the side-effects of botanical nano-insecticides and the main challenges to improve their sustainability in term of ecological and production cost.