Control efficacy of
Bt
‐(
Cry1Ab
+
Cry1F
) maize against
Spodoptera frugip
Lingyun Gao, Wei He, Haitao Li, Wenhui Wang, Xianming Yang, Kongming Wu Abstract
BACKGROUND
Spodoptera frugiperda (J. E. Smith) is a major invasive pest of maize in Asia, with migration pathways extending annually in July into North China, a key maize‐producing region. However, the potential utility of Bt maize for controlling this pest remains unclear. In this study, we evaluated the insecticidal activity and field control efficacy of Bt‐(Cry1Ab + Cry1F) maize against the insect in North China.
RESULTS
Bt insecticidal protein levels in Bt‐(Cry1Ab + Cry1F) maize tissues followed the order: V6–8 leaves > V12 leaves > VT tassels, R4 kernels > R1 silks. Correspondingly, larval mortality was 100 ± 0% after leaf feeding for 7 days and 84.49 ± 1.71%, 75.65 ± 1.50%, and 82.57 ± 1.08% after feeding on VT tassels, R1 silks, and R4 kernels, respectively. V5 leaf feeding significantly reduced pupal weight, pupation and emergence rates, and fecundity of 1st‐ and 3rd‐instar S. frugiperda , while prolonging larval development. Field infestation experiments showed significantly lower larval density and leaf and plant damage rates of S. frugiperda in Bt‐(Cry1Ab + Cry1F) maize than those in conventional maize fields, with larval control efficacy of 61.14–100%. Field surveys in 2023–2025 revealed no S. frugiperda larvae in Bt‐(Cry1Ab + Cry1F) maize fields throughout the entire growth period, with plants exhibiting no damage. In contrast, conventional maize suffered continuous damage during the reproductive growth stage, with a peak larval population of 9.33–12.67 per 100 plants and a plant damage rate of 64–74%.
CONCLUSION
This study demonstrates that Bt‐(Cry1Ab + Cry1F) maize can effectively control this pest in the region and provide a green tool for area‐wide management of S. frugiperda . © 2026 Society of Chemical Industry.