Fall armyworm (Spodoptera frugiperda) is a highly destructive lepidopteran pest belonging to the family Noctuidae, with maize (corn) as its primary host. Its life cycle comprises four stages, egg, larva, pupa, and adult moth, each contributing to its persistence and rapid spread in maize-growing regions.
Why Fall Armyworm Is Difficult to Control
Fall armyworm exhibits several biological and behavioural traits that make management particularly challenging:
1. Rapid Reproduction
A single female can lay up to 1,500 eggs, enabling populations to build up quickly and cause severe infestation in a short period.
2. High Mobility
The adult moth is a strong flyer capable of travelling long distances on wind currents. This long-range dispersal allows the pest to spread rapidly across regions and reinfest previously treated fields.
3. Nocturnal Feeding Behaviour
Larvae feed mainly at night, making them difficult to detect through daytime scouting. This hidden feeding behaviour often delays identification until damage is already advanced.
4. Polyphagous Feeding
Although maize is the preferred host, fall armyworm can feed on over 80 plant species, including rice, sorghum, cotton, and vegetables. This broad host range allows populations to survive across diverse ecosystems and cropping systems.
5. Cryptic Habits
Larvae conceal themselves deep inside maize whorls and leaf folds, where they are protected from predators, environmental conditions, and chemical sprays. This hidden feeding location reduces contact with applied insecticides.
6. Overlapping Life Stages
Eggs, larvae, and pupae often occur simultaneously in the same field. As a result, no single insecticide application can eliminate all stages, complicating control efforts.
Effective Fall Armyworm Management in Maize
Successful control of fall armyworm requires integrating an understanding of its biology with well-timed insecticide use.
1. Early Detection and Monitoring
Scout fields frequently, especially during the whorl and pre-tassel stages. Early detection allows targeting of small larvae, which are more susceptible to insecticides.
2. Insecticide Selection
Use insecticides with multiple modes of action to reduce the risk of resistance development and achieve thorough control across life stages.
3. Proper Timing of Application
Apply insecticides when larvae are young and actively feeding. Since feeding occurs mostly at night, early morning or late evening applications improve effectiveness.
4. Application Technique
Ensure thorough coverage of the plant particularly the whorl, leaf folds, and internal feeding sites. Adjust spray pressure and nozzle type to penetrate the canopy and reach concealed larvae.
5. Correct Rates and Adherence to Label Instructions
Always apply insecticides according to recommended rates and safety guidelines. Over- or under-dosing reduces efficacy and increases resistance risk.
Recommended Insecticide Combinations for Fall Armyworm Control
The most reliable control has been achieved using strong, complementary insecticide combinations. The following Greenlife-recommended mixtures are effective when applied correctly:
Benzoron 110 ME 2.5ml + Integra 3 ml per 20 L of waterÂ
Escort 50 EC:
20–25 ml + Integra 3 ml per 20 L of waterOccasion Star 200 SC:
3 ml + Integra 3 ml per 20 L of waterIndoking 300 SC:
3 ml + Integra 3 ml per 20 L of waterLegacy Extreme 500 WDG:
2 g + Integra 3 ml per 20 L of water
These combinations deliver strong knockdown and residual activity, ensuring effective suppression of FAW populations and protection of maize crops.
Expert Support
For tailored recommendations, field diagnosis, or technical guidance, Greenlife Crop Protection Africa is available to support farmers in implementing the most effective FAW management strategies.