GREEN LEAF HOPPER IN PADDY

GREEN LEAF HOPPER IN PADDY

Telugu name: Pacha doma

Scientific name: Nephotettix virescens

Identification of the pest:

Eggs: 

Greenish transparent eggs are deposited in the midrib of leaf blade or sheath of rice or green grass. They are laid in batches of 10 to 15 arranged in a single row.

Nymph: 

The nymphs are soft bodied, yellow white in colour. Gradually the colour changes to green.

Adult: 

Adults are 3-5 mm long, bright green with variable black markings, wedge shaped with a characteristic diagonal movement. Male insect has a black spot in middle of the forewings that is absent in females. The insect is active during July to September. 

Lifecycle:

➤ Female inserts 200-300 eggs in batches of 8-16 in midrib of the leaf blade.Egg period 6-7 days.

➤Nymphs undergo 5 instars & become adult in 25 days.

➤ Adult longevity 20-30 days.

➤Population normally increase from August onwards, reaches maximum during Sep-Oct and declines from November.

Symptoms:

  • Yellowing of leaves from tip to downwards.
  • Plant stunted with reduced vigor.
  • Withering or complete drying of plant by sucking the plant sap.
  • White or pale yellow eggs inside leaf sheaths or midribs.
  • Pale green adults feeding on upper parts of the crop.

Favourable  Conditions:

Temperature: Leafhoppers favor warm temperatures, with 25-32°C being ideal for their development and activity.

Humidity: Moderate humidity levels (50-70%) provide favorable conditions for egg laying, nymph survival, and adult activity.

ETL: 5/hill at vegetative stage (or) 10/hill at flowering (or) 2/hill in tungro endemic area.

Management:

Cultural practices:

  • The most effective means of GLH management is to use GLH-resistant and tungro-resistant varieties like IR 50, IR 54, IR 64, CR 1009, PY 3, Co 46 and white ponni.
  • Apply neem cake @ 12.5 kg/20 cent nursery as basal dose.
  • Transplanting older seedlings (>3 weeks) reduces viral disease susceptibility transmitted by leafhoppers.
  • Nitrogen should be applied as needed to avoid contributing to population or hindering plant recovery from plant hopper damage by applying insufficient nitrogen.
  • Good weed control in the field and on the bunds removes the preferred grassy hosts of Green leaf hopper and promotes crop vigor.
  • Crop rotation with a non-rice crop during the dry season decreases alternate hosts for diseases.
  • Upland rice intercropped with soybean reduces the incidence of leafhoppers on rice compared to rice alone.

Biological Methods:

  • The major egg parasitoids are:
  • Oligosita yasumatsui (Hymenoptera:Trichogrammatidae).
  • Anagrus spp. (Hymenoptera: Mymaridae).
  • Gonatocerus spp. (Hymenoptera: Mymaridae).
  • The most abundant predator is the green mired bug Cyrtorhinus lividipennis which predate on both eggs and nymphs.Strepsipterans, small wasps, pipunculid flies, and nematodes parasitize both the nymphs and adults.
  • They are also attacked by aquatic veliid bugs, nabid bugs, empid flies, damselflies, dragonflies, and spiders.
  • A fungal pathogen infects both the nymphs and adults of the green leafhopper.

Trap methods:

  • Set up light traps to attract and kill the moths. Set up light trap one for at least 5 ha.
  • Set up bird perches (40 to 50/ha) of Insectivorous Birds at vegetative phase of crop.
  • Monitor through phermone traps (@ 10 to 12/ha for timely control measures. Change the lure at 15-20 days intervals.

Chemical Control:

  • Scout the field for the presence of Tungro and Green leaf hopper. Check 20 hills while walking diagonally across a transplanted field.
  • Spray insecticides twice, 15 and 30 days after transplanting.

Spray any one of the following:

  • Fenthion 100 EC 40 ml (or) Quinalphos 25 EC 80 ml (or) Phosalone 35 EC 120 ml (or) Monocrotophos 36 SL 40 ml.
  • Maintain 2.5 cm of water in the nursery and broadcast anyone of the following in 20 cents Carbofuran 3 G 3.5 kg (or) Phorate 10 G 1.0 kg (or) Quinalphos 5 G 2.0 kg
  • For effective control of green leaf hopper use Biopesticide “Dr. ELIMINATOR”@250ml/acre.

FAQs:

1. How to spot green leaf hopper infestations early?

 Look for yellowing or stunted rice plants and an increase in hopper activity on the leaves. Regular field monitoring helps.

2. What are the resistant varities available for green leaf hopper?

Yes, varieties like IR36 and IR64 show resistance to green leaf hoppers. Check with your local agriculture office for region-specific recommendations.

3. How often should I apply insecticides to control green leaf hoppers?

 Use insecticides only when infestation crosses the threshold (10 hoppers per hill) and rotate chemicals to avoid resistance.

4. Can weather affect green leaf hopper populations?

Yes, warm, humid conditions often lead to outbreaks. Be extra vigilant during these periods.

5. What cultural practices can reduce green leaf hopper attacks?

Avoid excess application of nitrogen, ensure proper drainage, and maintain field hygiene by removing weeds and stubble.

 

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