Botanical Insecticides: Major Sources, and Chemical and Mechanistic Insights

The agriculture sector is one of the largest users of various synthetic (chemical) insecticides. However, extensive use of synthetic (chemical) insecticides has raised significant concerns, including environmental pollution, harm to non-target organisms, the development of pest resistance, and potential health risks to humans. Botanical insecticides, pest control products derived from plants, have become an important environmentally friendly alternative to synthetic (chemical) insecticides. In addition to their environmentally friendly nature, botanical insecticides offer benefits like low toxicity to non-target organisms, biodegradability, and reduced risk of pest resistance. Taking into account recent literature, this chapter aims to: (i) provide an overview of important insect pests and their impacts on crop health and productivity; (ii) highlight, with examples, the sources and chemical nature of major botanical insecticides (such as azadirachtin, pyrethrum, rotenone, allicin, and lemongrass essential oils); (iii) discuss important mechanistic insights (working principles) underlying botanical insecticides; and (iv) enlighten readers on the major challenges and future directions in this field.