Phytochemical strategies for combating Spodoptera litura (Fab.): a review of botanicals and their metabolites

The adverse effects of the lepidopteran pest, Spodoptera litura (Fab.) on crops, result in significant economic losses due to decreased crop productivity and the cost of pest control measures. Using synthetic chemicals to manage this polyphagous pest can adversely impact the environment and contribute to the development of pesticide resistance in other insects. Integrated pest management strategies, including biological control agents, are often recommended to manage S. litura infestations in a more sustainable and environmentally friendly manner. Compared with synthetic chemicals, herbal pesticides are generally considered nontoxic for the environment. They often have lower toxicity toward non-target organisms, thus reducing the risk of harming beneficial animals and other wildlife. Botanicals include a variety of phytocompounds that can potentially help in managing polyphagous pests, such as S. litura. Improving herbal-based nano-pesticides (Hb-Np) that can serve as carriers for bioactive compounds would enable their controlled and targeted release. Therefore, the present review aims to highlight the impact of different resistance mechanisms employed by the lepidopteran larvae against synthetic chemicals and efficacy of herbal extracts, essential oils, and herbal-based nano-formulations in targeting the polyphagous pest, S. litura, and the key challenges associated with sustainable pest management in the agriculture sector.