Nanomaterials for Postharvest Management of Insect Pests: Current State and Future Perspectives

Globally, between one quarter and one-third of total grains produced each year are lost during storage mainly through infestation of insect pests. Among the available control options such as chemical and physical techniques, fumigation with aluminum phosphide (AlP) is so far considered the best control strategy against storage insect pests. However, these insect pests are now developing resistance against AIP due to its indiscriminate use due to non-availability of any effective alternative control option. Resistance to AIP among storage insect pests is increasing, and its inhalation has shown adverse effects on animals and human beings. Nanotechnology has opened up a wide range of opportunities in various fields such as agriculture (pesticides, fertilizers, etc.), pharmaceuticals, and electronics. One of the applications of nanotechnology is the usage of nanomaterial-based insecticide formulations for mitigating field and storage insect pests. Several formulations, namely, nanoemulsions, nanosuspensions, controlled release formulations, and solid-based nanopesticides, have been developed with different modes of action and application. The major advantage is their small size which helps in proper spreading on the pest surface, and thus, better action than conventional pesticides is achieved. Besides their minute size, these have no or reduced harmful effects on non-target species. Nanopesticides can therefore provide green and efficient alternatives for the management of insect pests of field and storage. However, an outcry against the utilization of nano-based pesticides is also revealed. It is considered by some that nano-insecticides may also have hazardous effects on humans as well as on the environment. Due to limited available data, nanopesticides have become a double-edged weapon. Therefore, nanomaterials need to be evaluated extensively for their large-scale adoption. In this article, we reviewed the nanoformulations that are developed and have proved effective against the insect pests under postharvest storage of grains.