Pests and diseases

Leafhoppers and jassids

Jassids · Planthoppers · పచ్చదోమ · దీపపు పురుగు

Insects and mites

The advice below comes from each crop's guide — every item shows its source, region and date. It is pending expert review; ask your local officer whether it suits your area.

Paddy

  • Pest prevention in the main field

    Remove or destroy stubble after harvest, keep fields free of weeds, trim field bunds and provide effective drainage. Avoid excessive nitrogen fertilizer. Avoid close planting, especially in brown planthopper (BPH) and leaf folder prone areas or seasons, and leave a 30 cm space after every 2.5 m. Use light traps (1 per hectare) and pheromone traps (12 per hectare) to monitor stem borer and leaf folder, and remove and destroy stem borer egg masses. In BPH-prone areas, avoid chemicals that cause resurgence, such as synthetic pyrethroids and quinalphos, and avoid repeated use of the same insecticide.

    Pending expert review
    Source
    Crop Production Guide – Agriculture 2020 (Directorate of Agriculture, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Rice – Pest management, main field, p. 50
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Groundnut

  • Leafhopper and leafminer: non-chemical measures

    For leafhopper, intercrop lablab with groundnut in a 1:4 ratio. For leafminer (leaf webber), set up a light trap at ground level between 8 and 11 pm.

    Pending expert review
    Source
    Crop Production Guide – Agriculture 2020 (Directorate of Agriculture, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Groundnut – Leafhopper & leafminer, p. 194
    Region
    Tamil Nadu
    Last updated
    2026-11-04
  • Chemical insecticides: ask before you spray

    The source lists insecticides for red hairy caterpillar, tobacco caterpillar, leafhopper, leafminer, earwig, white grubs, aphids, thrips and termites. Many are hazardous, and some may be restricted. Choose a product only with your local Agriculture Officer, and spray only after the pest crosses the threshold level.

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

    Pending expert review
    Source
    Crop Production Guide – Agriculture 2020 (Directorate of Agriculture, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Groundnut – Pest management strategies, pp. 193–195
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Cotton

  • 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.

    Pending expert review
    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

Sesame

  • Root rot and phyllody

    Root rot: apply Pseudomonas fluorescens or Trichoderma asperellum at 2.5 kg/ha with 50 kg of well-decomposed FYM or sand at 30 days after sowing. Phyllody (spread by a leafhopper): remove and destroy infected plants; neem seed kernel extract 5% or neem oil 2% against the vector, combined with intercropping sesame + red gram (6:1).

    Pending expert review
    Source
    Crop Production Guide – Agriculture 2020 (Directorate of Agriculture, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Sesame – Disease management (Root rot, phyllody), p. 203
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Okra

  • Chemical pesticides: ask before you spray

    The source lists chemical sprays for fruit borers, leafhopper, aphids, mites, whiteflies, powdery mildew and nematodes. Many are hazardous, and some may be restricted. Vegetables are eaten fresh, so choose any product only with your local Agriculture Officer.

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

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Bhendi – Plant protection, pp. 70–71
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Cucumber

  • Pests and weeds: ask before you spray

    The source lists a chemical spray for aphids and jassids and pre-emergence weedicides. 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.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Cucumber – Plant protection; sowing (herbicide), pp. 98–99
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Bottle gourd

  • Pests and diseases: ask before you spray

    The source lists chemical sprays for aphids, jassids, fruit borers and caterpillars, red spider mite, powdery mildew and downy mildew. 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.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Bottle gourd – Plant protection, pp. 90–91
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Bitter gourd

  • Pests and diseases: ask before you spray

    The source lists chemical sprays for aphids, jassids, fruit borers and caterpillars, red spider mite, powdery mildew and downy mildew. 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.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Bitter gourd – Plant protection, pp. 93–94
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Ridge gourd

  • Pests and diseases: ask before you spray

    The source lists chemical sprays for aphids, jassids, fruit borers and caterpillars, red spider mite, powdery mildew and downy mildew. 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.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Ribbed gourd – Plant protection, p. 88
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Snake gourd

  • Pests and diseases: ask before you spray

    The source lists chemical sprays for aphids, jassids, fruit borers and caterpillars, red spider mite, powdery mildew and downy mildew. 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.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Snake gourd – Plant protection, pp. 85–86
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Pumpkin

  • Pests and diseases: ask before you spray

    The source lists chemical sprays for aphids, jassids, fruit borers and caterpillars, red spider mite, powdery mildew and downy mildew, and lists red pumpkin beetle, leaf miner, thrips, whitefly and pumpkin caterpillar among the pests. 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.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Pumpkin – Plant protection, p. 83
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Ash gourd

  • Pests and diseases: ask before you spray

    The source lists chemical sprays for aphids, jassids, fruit borers and caterpillars, red spider mite, powdery mildew and downy mildew. 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.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Ash gourd – Plant protection, pp. 96–97
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Cluster bean

  • Pests and diseases: ask before you spray

    The source lists chemical treatments for leafhoppers, aphids, whitefly, ash weevils, leaf spot and powdery mildew (neem-based azadirachtin is listed for ash weevils). 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.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Cluster bean – Plant protection, pp. 107–108
    Region
    Tamil Nadu
    Last updated
    2026-11-05

French bean

  • Pests and diseases: ask before you spray

    The source lists chemical treatments for white grub, stem weevil, leafhoppers, aphids, ash weevils, pod borer, powdery mildew, rust, anthracnose, leaf spot and root rot. 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.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), French bean – Plant protection, pp. 111–113
    Region
    Tamil Nadu
    Last updated
    2026-11-05

Potato

  • 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.

    Pending expert review
    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

Rose

  • Pests: non-chemical measures in the source

    Rose chafer beetle: hand-pick the beetles during the day and destroy them. White grub: set up a light trap to attract the adult beetles. Red scale: rub off the scales with cotton soaked in kerosene, and cut and burn affected branches. Neem oil 3% is listed for thrips, aphids and leafhoppers.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Rose – Pests (non-chemical measures), pp. 248–249
    Region
    Tamil Nadu
    Last updated
    2026-11-05
  • Pests and diseases: ask before you spray

    The source lists chemical sprays for chafer beetle, white grub, red scale, mealybug, thrips, aphids, leafhoppers, two-spotted mite, black spot and powdery mildew. 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.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Rose – Plant protection, pp. 248–249
    Region
    Tamil Nadu
    Last updated
    2026-11-05