ABSTRACT
Plant products and their components that cause insects to make oriented movements toward their source are known as insect attractants. They influence both gustatory and olfactory receptors or sensilla. Isothiocyantes from seeds of Crucifera and sugar and molasses and terpenes from bark with pheromones are natural attractants for various insects of Cruciferae and bark beetles. Repellents are desirable chemicals offering protection with minimal impact on the ecosystem by driving away insect pests from treated materials by stimulating olfactory or other insect receptors. Plant products and their pesticides inhibit feeding or disrupt insect feeding by rendering the treated materials unattractive or unpalatable. Some botanical pesticides are toxic and cause death to stored product insects. Toxicants are specific types of chemicals that directly kill insects and are also referred to as insecticides. Ground plant parts, extracts, oils and vapors also suppressed the fecundity and fertility of many insects.
