Cutworm

Monitoring with traps

Use light traps (modified Robinson type, 125 W mercury lamp) to follow insect populations. Set up species-specific sex pheromone traps at 12 per hectare for pink bollworm, tobacco cutworm (Spodoptera litura) and American bollworm. Apply insecticides only where absolutely necessary, when the pest population or damage reaches the threshold level.

Source

Crop Production Guide – Agriculture 2020 (Directorate of Agriculture, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Cotton – Pest monitoring, p. 272

Region

Tamil Nadu

Last updated

2026-11-04

When to act: pest threshold levels

Economic threshold levels given for cotton: thrips – 50 nymphs or adults per 50 leaves; aphids – 15% of plants infested; leafhopper – 50 nymphs or adults per 50 leaves; mite – 10 per cm² of leaf; spotted and spiny bollworms – 10% of shoots, squares or bolls infested; pink bollworm – 10% of fruiting parts infested; Helicoverpa (American bollworm) – one egg or one larva per plant; whiteflies – 5–10 per leaf; stem weevil – 10% infestation; tobacco cutworm – 8 egg masses per 100 m row.

Source

Crop Production Guide – Agriculture 2020 (Directorate of Agriculture, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Cotton – Economic threshold levels, p. 272

Region

Tamil Nadu

Last updated

2026-11-04

Chemical pesticides: ask before you spray

The source lists chemical sprays for cutworms and Helicoverpa, mealybug, bud borer, thrips and red spider mite. Many are hazardous, and some may be restricted. Choose a product only with your local Agriculture Officer.

Follow the instructions on the product label. Consult your local Agriculture Officer before use.

Source

Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Marigold (precision) – Plant protection, p. 258

Region

Tamil Nadu

Last updated

2026-11-04

When to act: pest threshold levels

Economic threshold levels for green gram: aphids – 20 per 2.5 cm shoot length; pod borers – 10% of pods affected; spotted pod borer – 3 per plant; stem fly – 10% of plants affected; tobacco cutworm – 8 egg masses per 100 m.

Source

Crop Production Guide – Agriculture 2020 (Directorate of Agriculture, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Greengram – Crop protection, ETL, p. 148

Region

Tamil Nadu

Last updated

2026-11-04

Pests and diseases: non-chemical measures in the source

Cutworms: summer ploughing, light traps (7–10 pm), pheromone traps (8/acre), hand-collecting larvae, NSKE 5% or Bacillus thuringiensis 2 g/l. Tuber moth: healthy tubers planted 15 cm deep, pheromone traps (5/acre), earthing up, and covering stored seed tubers with lantana or eucalyptus branches. Nematodes: do not grow potato year after year in the same field. Late blight and brown rot: use disease-free seed, good drainage, and remove affected plants. Viruses: use virus-free seed and pull out affected plants.

Source

Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Potato – Plant protection (non-chemical measures), pp. 135–137

Region

Tamil Nadu

Last updated

2026-11-04

Pests and diseases: ask before you spray

The source lists chemical treatments for cutworms, tuber moth, aphids, jassids, thrips, late blight, early blight and the aphids that spread viruses. Choose any product only with your local Horticulture or Agriculture Officer.

Follow the instructions on the product label. Consult your local Agriculture Officer before use.

Source

Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Potato – Plant protection, pp. 135–137

Region

Tamil Nadu

Last updated

2026-11-04