Introduction
Fall Armyworm (Spodoptera frugiperda) has become a major concern for Punjab’s maize growers. Known for its destructive feeding behavior, this pest has not only spread across various districts of Pakistan but is now showing signs of resistance to conventional control methods. As 2025 unfolds, new resistance reports are emerging, urging stakeholders to rethink their pest management strategies.
What Is Fall Armyworm?
The Fall Armyworm (FAW) is a migratory pest native to the Americas. Since its arrival in Asia, it has devastated cereal crops, especially maize, in various agro-ecological zones. The pest:
Attacks over 80 plant species
Is active year-round in warmer climates
Damages the whorl stage of maize and reduces yields by up to 40–60%
FAW is now permanently established in Pakistan and requires integrated pest resistance management.
Resistance Reports from Punjab (2024–2025)
Recent field surveys and resistance monitoring in Punjab show alarming trends:
Key Districts Reporting Resistance:
Okara
Vehari
Lodhran
Pakpattan
Khanewal
Observed Resistance Patterns:
Reduced efficacy of synthetic pyrethroids (e.g., cypermethrin, deltamethrin)
Cross-resistance to organophosphates (e.g., chlorpyrifos)
Overuse of same mode-of-action (MoA) pesticides
Improper spray intervals & dosages
According to Ayub Agricultural Research Institute (AARI) trials (2024), over 50% of tested FAW populations showed moderate to high resistance levels to two or more pesticide groups.
Factors Driving Resistance
Understanding the drivers of resistance helps mitigate future risk. Key causes include:
Continuous exposure to single pesticide classes
Lack of rotation between different MoAs
Unregistered or low-quality formulations
Poor scouting and delayed response
Climate conditions favoring rapid reproduction
Economic Impact on Punjab’s Maize Growers
Average yield losses reported: 18–32%
Additional costs for chemical sprays: PKR 4,000–7,000 per acre
Smallholder farmers most affected due to limited awareness
Rising input cost per acre may reduce farmer profitability drastically
For a complete guide on maize, visit Maize in Pakistan – Agronomy & Value Chain.
Integrated Resistance Management (IRM) Strategy
To tackle Fall Armyworm resistance, experts recommend IRM principles:
1. Pest Scouting and Early Detection
Monitor maize fields twice a week
Use pheromone traps to detect male moth populations
Identify egg masses and larvae at early stages
2. Biological Control Options
Release of Trichogramma chilonis for egg parasitism
Encourage natural predators like ladybird beetles and lacewings
3. Rotate Pesticide Classes
Follow IRAC classification for rotating active ingredients
Avoid back-to-back sprays of same MoA
Apply insecticides at recommended doses only
4. Use of Biopesticides
Neem-based formulations or Bacillus thuringiensis (Bt)
Minimize environmental impact and delay resistance development
5. Crop Diversification and Rotation
Avoid continuous maize monoculture
Practice intercropping and rotation with legumes or vegetables
| Resistance Level | Insecticide Name | Chemical Group (IRAC MoA) | Mode of Action | Remarks / Notes |
|---|---|---|---|---|
| Resistant | Cypermethrin | Pyrethroid (3A) | Sodium channel modulator | High resistance reported in Punjab |
| Resistant | Deltamethrin | Pyrethroid (3A) | Sodium channel modulator | Ineffective in multiple districts |
| Resistant | Chlorpyrifos | Organophosphate (1B) | Acetylcholinesterase inhibitor | Cross-resistance increasing |
| Resistant | Lambda-cyhalothrin | Pyrethroid (3A) | Sodium channel modulator | Decreased efficacy |
| Low Resistance | Emamectin Benzoate | Avermectin (6) | Chloride channel activator | Some early tolerance detected |
| Low Resistance | Spinosad | Spinosyn (5) | Nicotinic acetylcholine receptor modulator | Use in rotation only |
| Low Resistance | Indoxacarb | Oxadiazine (22A) | Sodium channel blocker | Avoid repeated use |
| Susceptible | Chlorantraniliprole (Coragen) | Diamide (28) | Ryanodine receptor modulator | Highly effective & preferred |
| Susceptible | Flubendiamide | Diamide (28) | Ryanodine receptor modulator | Low resistance risk |
| Susceptible | Methoxyfenozide | Diacylhydrazine (18) | Ecdysone receptor agonist | Selective & safe for beneficials |
| Susceptible | Bacillus thuringiensis (Bt) | Microbial | Toxin disrupts midgut lining | Use early in larvae stage |
| Susceptible | Neem Extracts / Azadirachtin | Botanical | Feeding deterrent / growth regulator | Use as part of IPM only |
Government and Research Interventions
Ongoing Measures:
Punjab Agriculture Department has launched a Fall Armyworm Monitoring Cell.
FAO and CIMMYT are supporting capacity building through workshops and trainings.
Subsidized pheromone traps and demo plots are being promoted.
📈 Future Recommendations:
Establish a nationwide resistance monitoring system
Train field assistants and extension workers
Promote Integrated Pest Management (IPM) adoption at farm level
For global updates, see the FAO Fall Armyworm Platform
Conclusion
The growing resistance of Fall Armyworm in Punjab poses a significant threat to food security and farmer livelihoods. Without strategic, science-backed approaches, reliance on chemical control will only worsen the situation. Through early detection, diversified control methods, and responsible pesticide use, Punjab can still manage this pest sustainably.