PESTS ON RICE

Rice Leaffolder Cnaphalocrocis medinalis  Pyraustidae  Lepidoptera

Biology

ü  Egg: Flat transparent, single eggs found on the under surface of the leaves.

ü  Larva: pale yellowish green, smooth, which folds of the leaves and webs them and stays inside the folded leaves and scrapes the green portion.

ü  The scrapped portion becomes white and papery.

ü  Grown up larva pupates inside the folded leaf in a loose silken cocoon.

ü  Adult: Moths are small in size and brownish orange in color. The forewings are light brown in color, with two distinct, dark wavy lines on each wing. The hind wings are light brown in color with one dark, wavy line and dark brown band along the margin.

ü  It completes 3-5 overlapping generation in each year.

Management:

v  Grow Resistant varieties: TNAU LFR 831311, Cauveri, Akash, TKM 6

v  Clipping of the affected leaves

v  Keep the bunds clean by  trimming and remove the weeds

v  Avoid use of excess  nitrogenous fertilizers

v  Set up light traps to attract and kill the moths

v  Release Trichogramma chilonis @ 1, 25,000/ha thrice on 37^th, 44^th & 51^st DAT, followed by three sprays of Monocrotophos 35 EC 1000 ml/ha on 58^th,65^th & 72^nd  DAT.

v  3% neem oil emulsion with 5litres of kerosene can be sprayed to control the pests effieciency.

v  Conserve predators like, spider,Mermithids,Damselfly,Ants,Rove beetles.

v  Apply  the fungal pathogens like, Beauveria bassiana, Zoopthora radicans

v  Spray 5% NSKE and 25 Kg of Fenithrothion 50 EC one litre or Chlorpyriphose20 EC 1.25 lit or Phasolone 35 EC 1.5 lit per ha. One spray at boot leaf stage gives adequate protection against RLF.

v  Spray NSKE 5 % or carbaryl 50 WP 1 Kg or chlorpyriphos 20 EC 1250 ml/ ha

v  Avoid resurgence inducing chemicals like Carbofuran.

  Swarming caterpillar or Armyworm:Spodoptera mauritia Noctuidae : Lepidoptera

ü  Sporadic pest appears during July- September.

Egg period: 7 days; Larval period: 20-25 days; Pupal period: 10-15 days

ü  Larva: Long, cylindrical, smooth and dark to pale green in color, with dull reddish and yellowish dorsal and sub dorsal stripes.

ü  Adult: medium size, Grayish brown moth with black spot near the anterior margin and irregular, wavy, black band along the lateral margin of forewing.. Hindwing whitish brown

ü  Cutting of seedlings in large scale, similar to cattle grazing by nocturnal feeding. Peduncles of ears bitten through in maturing crop.     

Management

v  Summer ploughing

v  Collection and destruction of egg masses

v  Flood the nursery to expose the hiding larvae to the surface and thus they picked up by birds.

v  Allow the ducks into the field to feed on the larvae.

v  Kerosinate the water while irrigation to suffocate and kill the larvae.

v  Set up light traps to attract adult moths.

v  Drain the water from the nursery and spray Chlorpyriphos 20EC 80 ml or Endosulfan 35 EC 80 ml during late evening.

v  Dusting neem cake / pungam cake powder @ 10 kg/ac.

v  Dusting of wood ash @ 10-12 kg/ac.

v  Keep neem leaves in bunches at 10 different places per acre.   

Caseworm        : Parapoynx stagnalis: Pyraustidae: Lepidoptera

ü  It is a sporadic pest, become serious in specific weather conditions.

ü  It is serious in young transplanted crop.

ü  Female moth lays about 50 eggs, singly on under surface of leaves, hatches in 2-6 days.

ü  Larva is pale green color, with a light brownish-orange head and thin hairs. It initially scrapes the chlorophyll later cut the leaf into small bits and construct tubular cases, live inside the cases. The case is replenished in each molting.

ü  The grown up larva pupates inside the case, which is attached to the base of the tiller.

ü  The adult moths are small, whitish in color with light brown, wavy markings on the white wings.

Management

·         Nursery - Mix 100 ml kerosene in standing water and  spray endosulfan 35 EC 30 ml / 8 cents nursery

·         The field should be filled with water upto 6 cm. Add one litre of kerosene , Dislodge the cases by running a rope over the young crop, so that the cases fall in the water and then drain the water from the field.

·         Spray  Monocrotophos 36 WSC 500 ml / ha.

 Whorl maggot: Hydrellia sesakii: Ephydridae : Diptera

ü  The pest become severe in water stagnated fields, when the plants are young.

ü  Egg: Long, cylindrical, white pasted on the leaves.

ü  Young maggots are pale white in color later become yellow.

ü  The maggot bore into shoots of young plants and feed on the inner tissues.

ü  Narrow stripes of whitish area are seen on margins, near the leaf tips of unfurled leaves. Leaves shriveled, plants stunted and maturity delayed.

ü  It pupates inside the shoot; adults are very small dull grey fly.

ETL : 25% damaged leaves.

Management

v  Remove the alternate hosts and adjust the time of planting (early)

v  Use early maturing  varieties

v  Optimum recommendation of potash fertilizer

v  Spray  Quinolphose 25 EC 1000 ml/ha.

Green leafhopper: Nephotettix nigropictus: N.cincticeps, N.virescens:            Cicadellidae : Hemiptera.

ü  Female hopper inserts the cylindrical eggs inside the epidermal layer of the leaf sheath of plants. Fecundity is 420.

ü  Nymphs are pale green in color, wingless, but are very active. Adults are green with black spot and black patch on the wings.

ü  Both nymphs and adults suck the sap from the leaves an succulent stem portions.

ü  The leaves of infested plants show yellowing, with drying of leaf tips. In case of severe infestation, the whole plant turns yellow, becomes stunted and finally dies.

ü  It is the vector of rice tungro virus disease and rice yellow dwarf disease.

ETL: 60 nos./25 sweepings-Nursery , 10nos/hill-Flowering stage,

5 nos/hill – Vegetative stage, 2 Nos/hill – Tungro endemic areas

Management

·         Use resistant varieties like IR 50, CR 1009, Co 46,Ptb 2,Ptb 18.

·         Remove wild grasses and weeds from the field bunds and field.

·         Apply neem cake @ 12.5 kg/20 cent nursery as basal dose

·         The vegetation on the bunds should also be sprayed with the insecticides

·         Set up light traps

·         Nursery should not be raised near the lamp post.

·         Dip the seedlings in neem seed kernel extract for 24 hrs before transplanting.

·         Apply neem cake as top dressing @ 50-60 kg/ac.

Brown planthopper: Nilaparvata lugens: Delphacidae : Hemiptera.

ü  It cause yield loss upto 10-70 percent/

ü  Eggs are inserted into the tissues of leaf sheath. Fecundity is 650.

ü  Nymphs are whitish. Adults are yellowish brown with dull white streaks on the thorax and black lines on the lateral side of the head.

ü  Bothe nymphs and adults congregate on the collar region of the plant and suck the sap.

ü  Hopper burn: Drying and browning of young plants. Circular patches of drying in the field, lodging of matured plant.

ü  Two forms namely, Macropterous (long winged) and brachyterous (short winged) are found, of which the former is responsible for migratory movement and colonization in other neighboring rice crops.

ü  Vector of Grassy stunt, Ragged stunt and wilted stunt.

ETL: 5-10 insects/hill.

Management

v  Use resistant/tolerant varieties like Aruna, ADT 36, Co 42, Co 46 IR 36, IR 72, PY 3, Ptb 33, Ptb 21, Divya, Asha.

v  Avoid close planting, provide adequate spacing.

v  Provide 30 cm rogue spacing at every 2.5 m to reduce the pest incidence.

v  Avoid use of excessive nitrogenous fertilizers.

v  Control irrigation by intermittent draining.

v  Set up light traps to monitor the pest population.

v  Set up yellow pan traps during day time

v  Conserve  natural enemies like Lycosa pseudoannulata, Cyrtorhinus lividipennis

v  Avoid synthetic pyrethroids, methyl parathion, fenthion and quinalphos causing resurgence

v  Drain the water before the use of insecticides

v  Spray NSKE 5% or 2% neem oil or  Iluppai oil  6%

v  Apply any insecticide

Preflowering

·         Phosphomodan 85 WSC 200 ml or Monocrotophos 36 WSC 500 ml or Imidachloprid 200 SL 100 ml/ac

Post flowering

·         Caboryl 10 D @ 10 Kg/ac.

Note : Direct the spray and dust towards the base of the plant

Earhead bug: Leptocorisa acuta:Coreidae : Hemiptera

ü  It is commonly known as gundhy bug

ü  Nymph: Green to brown. Adult: Brown, slender with long antennae and legs.

ü  Both nymph and adult suck the sap from the milky grains; the individual grains become chaffy. Black or brown spots appear around the feeding puncture. PECKY GRAINS.

       Management

·         Collection of adults using net and killing them.

·         Remove the alternate host

·         Use light traps.

·         Dust any one of the following at 25 kg/ha twice, the first during flowering and second a week later

1.       Quinalphos  1.5 D                                          

2.       Carbaryl        10 D

3.       Malathion        5 D

4.       KKM             10 D

5.       KKM dust formulation consists of 10% of Acorus calamus rhizome powder and 90% of fly ash

6.       This dust formulation repels the rice earhead bug.                

Spray any one of the following twice as above

·         Fenthion 100 EC @ 500 ml/ha or Malathion 50 EC @ 500 ml/ha    

·         Neem seed kernel extract 5% @  25 kg/ha or Notchi or Prosopis leaf extract 10% .

  Black bug: Scotinophara lurida: Podopidae : Hemiptera

ü  Adult: brownish black bugs with a prominent scutellum and pronotum having a spine on either side.

ü  Presence of bugs at the base of the plants. Plants stunted with reduced number of tillers. Leaves turns reddish- brown or yellow and dry  (bug burn).

ü  Both nymph and adult cause damage to the crop.

  Red spotted bug: Menida histrio: Pentatomidae : Hemiptera.

ü  Orange colored bugs make the individual grains as chaffy.

Striped bug/ Nama  vandu: Tetroda histeroides:Pentatomidae : Hemiptera

ü  Adult: Brown bug with a prominent ‘V’ shaped mark on its back.

ü  Infested leaves become yellow.

Mealy bug: Brevennia rehi: Pseudococcidae: Hemiptera

ü  Both nymph and adult cause damage to the crop.

ü  Nymph: Pale yellowish –white; Adult: Reddish- white, soft bodied and are covered by a white, powdery waxy coatings.

      v  During main field preparation - remove the grasses from the bunds and trim the bunds

v  Remove and destroy the affected plants.

v   Spray any one of the following insecticides in the initial stage of infestation

o   Dimethoate 30 EC 500 ml/ha

o   Methyl demeton 25 EC@ 500 ml/ha.

v  Conserve the natural enemies like Scymnus sp.,Anatrichus pygmaeus, and Mepachymerus ensifer

                Source: TNAU Agritech portal