Effect of soil-applied silicon on the development, survival, and reproduction of Alabama argillacea (Lepidoptera: Noctuidae)

Abstract

Abstract The cotton leafworm, Alabama argillacea (Hübner, 1818) (Lepidoptera: Noctuidae), is a major defoliating pest of cotton. Although Bt cotton technologies currently available in Brazil effectively control this species, it remains an important pest in structured refuge areas, organic production systems, and colored-fiber cotton crops, where alternative management strategies are required. This study evaluated the effects of silicon (Si) fertilization on the development, survival, and reproduction of A. argillacea. The experiment was conducted under greenhouse and laboratory conditions using cotton plants grown without Si or fertilized with 150 (300 kg ha−1) or 300 mg Si kg−1 soil (600 kg ha−1). Silicon accumulated in cotton leaves in a dose-dependent manner, significantly impairing insect performance. Larval survival declined from 89.6% in the control to 10.4% at the highest Si dose, and no larvae completed pupation under this treatment. The intermediate Si dose reduced pupal weight, increased the proportion of males in the offspring, and decreased fecundity and egg viability. These results demonstrate that soil-applied Si enhances cotton resistance to A. argillacea by reducing its survival, development, and reproductive potential, supporting its use as a sustainable component of integrated pest management.