Taro armyworm moth

Spodoptera litura

1. Identification

• Common name: Taro caterpillar
• Scientific name: Spodoptera litura Fabricius
• Order: Lepidoptera
• Family: Noctuidae

2. Pest description

• Caterpillars of variable coloration, usually greenish-brown to brown, with light and dark longitudinal bands.
• Head with a characteristic reticulated pattern.
• Adults with brownish forewings with well-defined reniform and orbicular spots; pale hindwings with a dark margin.
• A highly polyphagous species, attacking leaves, shoots and reproductive structures.
• Feeding behaviour similar to Spodoptera frugiperda, but with a higher incidence in vegetables and tropical crops.

3. Main hosts

• Taro.
• Soybean.
• Cotton.
• Tomato.
• Pepper.
• Potato.
• Tobacco.
• Various vegetables and wild plants.

4. Symptoms and damage

• Initial scrapings on the leaves, progressing to perforations and partial defoliation.
• Severe damage to young leaves and shoots.
• Attack on tender fruits and floral structures.
• Reduced plant vigour and significant productivity losses.
• In taro crops, it can rapidly destroy the leaf area, compromising the development of the rhizomes.

5. Biological cycle

• Several generations per year, accelerated in warm and humid climates.
• Eggs laid in masses covered by scales from the female.
• Very voracious caterpillars, with rapid development and high damage potential.
• Pupation in the soil, in shallow chambers.
• Adults active for long periods in tropical and subtropical regions.

6. Monitoring

• Observation of scrapings, perforations and defoliation on young leaves.
• Inspection of shoots and reproductive structures.
• Pheromone traps for detection and flight tracking.
• Assessment of the percentage of damaged plants through direct sampling.

7. Management measures

• Cultural: destruction of crop residues, crop rotation and control of wild host plants.
• Preventive: choice of more tolerant varieties, practices that reduce the attractiveness of young plants and balanced management of fertilisation.
• Biological: application of Bacillus thuringiensis on young caterpillars and promotion of natural parasitoids.
• Integrated protection: monitoring with pheromones, definition of intervention thresholds, judicious use of authorised insecticides and rotation of modes of action.

Bibliographic references

• CABI – Invasive Species Compendium – Spodoptera litura.
• EPPO Global Database – Spodoptera litura.
• Ahmad, M., Ghaffar, A., & Rafiq, M. (2013). Host range and damage potential of Spodoptera litura. Crop Protection, 52, 1–7.
• Sparks, T. C. (2013). Insecticide resistance management and the role of Spodoptera species. Annual Review of Entomology, 58, 467–487.