BROWN PLANT HOPPER IN PADDY

Telugu name: sudi doma

Scientific name: Nilaparvata lugens

 Identification of the pest:

Egg:

Eggs are laid in a group of 2 to 12 in leaf sheath (near the plant base or in the ventral midribs of leaf blades).White, transparent, slender cylindrical and curved eggs are thrust in straight-line in two rows. (They are covered with a dome shaped egg plug secreted by the female. Only the tips protrude from the plant surface).

Nymph:

Freshly hatched nymph is cottony white, 0.6 mm long and it turns purple-brown, 3.0 mm long in the fifth instar.

Adult:

Adult hopper is 4.5-5.0 mm long and has a yellowish brown to dark brown body. The wings are sub hyaline with a dull yellowish tint. It has two characteristic wing morphs: macropterous (long winged) and brachypterous (short winged).

Lifecycle:

Eggs are laid in the midrib of the leaf blades, 4-10 in an egg mass; they are cylindrical, slightly curved, 1 mm long, white at first, darker when about to hatch, with two spots - the eyes of the nymph. The eggs hatch in 4-8 days. Nymphs are creamy white with a pale brown tinge, later becoming dark brown. There are four to five moults. The final nymphs are nearly 3 mm long, with a line from the top of the head to the middle of the body where it is widest. Adults are brownish black with a yellowish-brown body. There are two forms, long winged and short winged.

          Infestations start with the arrival of the winged form, which lay eggs and produces the wingless form. Winged forms develop when numbers are high; females are about 4 mm and males 4.5 mm; wingless forms are smaller. After harvest, the planthoppers migrate to grasses,   or spread to new crops of rice. Brown planthoppers live for up to 20 days.

Symptoms:

• Premature yellowing of leaves and drying of plants in isolated circular patches.
• Drying of plants spreads in a circular fashion.
• Sooty mould.
• Exuviae at the base of plants.
• Affected stems become soft and are unfit for use as straw.

Favourable conditions:

Warm temperatures: Brown plant hopper prefers warm temperatures around 27°C to 33°C, with optimal development rates within this range.Higher temperatures (above 38°C) and lower temperatures (below 15°C) can hinder their survival and reproduction.

High humidity: Brown plant hopper populations flourish in humid environments with relative humidity above 70%. Dry conditions can desiccate eggs and nymphs, reducing their survival rates.

ETL: 1 hopper/tiller in the absence of  predatory spider

            2 hoppers/tiller when spider is present at 1/hill.

Management:

• Cultural practices:
• Draining the rice field for 3-4 days is recommended during the early stage of infestation.
• Nitrogen application can be split to reduce Brown plant hopper buildup.
• Synchronous planting within 3 weeks of staggering and maintaining a free-rice period could also decrease the build-up of Brown plant hopper.
• There are varieties released by IRRI, which contain genes for Brown plant hopper resistance, like IR26, IR64, IR36, IR56, and IR72.
• Use resistant varieties like PY 3, CO 42, ADT 35, ADT 37, PTB 33 and PTB 21, Aruna, Kanaka, Karthika, Krishnaveni, Makon, Abhey, Asha, Divya.
• Avoid close planting and provide 30 cm rogue spacing at every 2.5 to 3.0 m to reduce the pest incidence.

Biological methods:

• Release of natural enemies like Lycosa pseudoannulata, Cyrtorhinus lividipennis adult (200-250 bugs/ha) during the peak incidence of brown plant hopper at 10 days interval.
• The common parasites of the eggs are the hymenopteran wasps. Eggs are preyed upon by mirid bugs and phytoseiid mites. Both eggs and nymphs are preyed upon by mirid bugs. Nymphs and adults are eaten by general predators, particularly spiders and coccinellid beetles.
• Hydrophilid and dytiscid beetles, dragonflies, damselflies, and bugs such as nepid, microveliid, and mesoveliid eat adults and nymphs that fall onto the water surface.
• Fungal pathogens also infect brown plant hoppers.

Trap methods:

• Set up light traps during night. 
• Use yellow pan traps during day time.
• Care should be taken not to place light traps near seed beds or fields.
• Installation of light traps with incandescent light at 1-2 m height @ 4/ acre to monitor the population.
• At the base of light trap put a tub filled with water to which kerosene was added to kill the trapped insects.

Chemical control:

• Drain the water before use of insecticides and direct the spray towards the base of the plants. Avoid use of insecticides causing resurgence such as synthetic pyrethroids, methyl parathuion, fenthion and quinalphos.
• Spray any one of the following:
• Carbaryl 10 D 25 kg/ha  (or) Acephate 75 SP 625 gm/ha (or)Carbofuran 3 G 17.5 kg/ha (or) Dichlorvos 76 WSC 350 ml/ha.
• For effective control of hoppers use Biopesticide “Dr.ELIMINATOR”@250ml/acre.
• Use of botanical methods: Neem oil 3% 15 lit/ha (or) Iluppai oil 6% 30 lit/ha (or) Neem seed kernel extract 5% 25 kg/ha.

FAQs:

1.What are the signs of a brown planthopper attack?

Look for yellowing leaves, wilting plants, and "hopper burn," where plants dry up quickly. Inspect stems for hoppers clustering at the base.

2.How can I prevent brown planthopper infestations?

Use resistant paddy varieties, plant at optimal spacing, and avoid overusing nitrogen fertilizers. Healthy practices reduce pest risks.

3. Are there eco-friendly ways to control brown planthoppers?

Yes! Introduce natural predators like spiders or apply neem-based sprays. These methods are safer for crops and the environment.

4.Can water management help with brown planthoppers?

Absolutely. Draining fields occasionally disrupts their habitat. Avoid waterlogging, which creates perfect breeding conditions.

5.When should I start monitoring for brown planthoppers?

 Begin monitoring early in the season, especially during warm, humid conditions. Regular checks can catch infestations early.

6. How do chemical pesticides fit into controlling brown planthoppers?

 Use pesticides as a last option. Target them specifically and avoid overuse to prevent resistance and protect beneficial insects.For effective control of brown plant hopper use Biopesticide “Dr. ELIMINATOR”@250 ml/acre.