Silicon(Si)is one of the most abundant elements in the earths crust,although it is not considered essential for plant growth.However,Si uptake is beneficial in alleviating abiotic and biotic stresses.This paper explores the knowledge and recent advances in understanding the role of Si in enhancing resistance of host plants to biotic stress,particularly herbivorous insects.Positive effects of Si are not always obvious since Si accumulation differs among plant species and cultivars.