Fall Armyworm (Spodoptera frugiperda) in Maize
Fall Armyworm (Spodoptera frugiperda) in Maize
The fall armyworm (FAW), Spodoptera frugiperda, is a highly destructive pest of maize and other crops. Native to the Americas, it has rapidly spread to Africa, Asia, and Australia, posing a significant threat to global food security. FAW larvae feed voraciously on maize leaves, whorls, and ears, leading to severe yield losses.
Identification and Damage
- FAW larvae are green to brown with a distinctive inverted "Y" marking on the head and four black spots arranged in a square on the last abdominal segment.
- Early feeding results in window-pane-like damage, while later instars create large, ragged holes and extensive defoliation.
- Infestation in the whorl causes "shot-hole" damage, and ear feeding reduces grain quality.
Management Strategies
- Cultural Control
- Early planting and crop rotation disrupt FAW life cycles.
- Intercropping with legumes or cover crops can reduce infestation.
- Biological Control
- Natural enemies such as parasitoid wasps (Telenomus remus, Cotesia marginiventris) and predators like lady beetles help regulate FAW populations.
- Entomopathogenic fungi (Metarhizium anisopliae, Beauveria bassiana) and bacteria (Bacillus thuringiensis) offer eco-friendly control options.
- Chemical Control
- Selective insecticides such as spinosad, chlorantraniliprole, or Bt-based products can be effective when applied early.
- Overuse of synthetic pyrethroids and organophosphates may lead to resistance, making integrated pest management (IPM) crucial.
- Host Plant Resistance
- Some maize varieties with native resistance or transgenic Bt maize provide protection against FAW feeding.
Conclusion
Managing FAW in maize requires an integrated approach combining cultural, biological, and chemical strategies. Regular monitoring, early intervention, and sustainable practices are key to minimizing FAW damage and ensuring maize productivity.
