Similar results were recorded when used potassium silicate for both the second and third larval instars, as the percentage reductions ranged 41.61-51.50 and 22.07-36.50%, respectively,and reduction in feeding consumption of the fourth instars ranged 15.56-31.50% . Goussain et al. (2002) registered increased mortality and cannibalism in groups of fall armyworm, Spodoptera frugiperda for the larvae of the second and sixth instars with silicon application.