Armyworms guide image
Plant pest guide

Armyworms

Signs: Chewed leaves, fast defoliation, and caterpillars feeding in groups.

Signs: Chewed leaves, fast defoliation, and caterpillars feeding in groups.Organic control list: Prevention note: Inspect in evening and early morning.

Quick facts

Signs: Chewed leaves, fast defoliation, and caterpillars feeding in groups.

Organic control list:

Prevention note: Inspect in evening and early morning.

  • Hand-pick.
  • Use BT while larvae are small.
  • Use row cover.
  • Encourage birds and predatory insects.

What to do next

  • Isolate the plant if it is indoors or in a crowded collection.
  • Inspect leaf undersides, stems, soil surface, and new growth.
  • Physically remove what you can with water, wiping, pruning, or hand-picking.
  • Use the lowest-risk organic control that matches the pest.
  • Repeat checks because eggs and hidden life stages often survive the first treatment.

Watch-outs

Do not spray first and identify later. The wrong treatment wastes time and may stress the plant.

FAQ

How do I use this plant pest guide?

Start with the light, soil, water, symptom, or purpose notes on this page, then make one careful change at a time.

What is the biggest mistake with Armyworms?

Do not spray first and identify later. The wrong treatment wastes time and may stress the plant.

When should I get more help?

Get local help if the plant is valuable, symptoms are spreading quickly, or outdoor disease and pest problems may affect nearby plants.