Evaluation of Silicon Impacts on Spodoptera frugiperda (Lepidoptera: Noctuidae) Larvae for Sustainable Management

Maize ranks as the 3rd most economically valuable cereal crop worldwide but its productivity is under severe threat by an invasive pest, Spodoptera frugiperda (Lepidoptera: Noctuidae). The 3rd instar S. frugiperda larvae are most damaging stage of lifecycle, that's why the present study is planned to evaluate the impacts of silicon dioxide (SiO2), potassium silicate (K2SiO3), and sodium silicate (Na2SiO3) @ 400 and 800 ppm against the 3rd instar larvae of S. frugiperda by using two application methods (soil drenching and foliar spray). Moreover, the impact of Si supplementation on biological parameters (pupation, adult emergence, and egg laying) was also recorded. The findings showed that SiO2 application through foliar spray @ 800 ppm concentration caused maximum mortality (12-36%) followed by K2SiO3 (8-32%) and Na2SiO3 (4-24%). The soil drenching method of silicon application was less effective in comparison to foliar spray. The surviving larvae showed negative impacts on growth and development, including pupation (48, 52, and 60%), adult emergence (41.67, 46.15, and 53.33%) and fecundity (46.20, 52.60, and 54.20) by SiO2, K2SiO3 and Na2SiO3 foliar spray @ 800 ppm respectively. The present study revealed that Si had a significant detrimental impact on immature stages of S. frugiperda. Consequently, Si treatment can reduce S. frugiperda reproduction which may ultimately decrease S. frugiperda establishment and early harm in maize. Silicon applications may offer a sustainable way to lessen S. frugiperda infestations, improving maize protection and lowering the need for conventional insecticides.