successful management of pest in paddy cultivation

SUCCESSFUL MANAGEMENT OF PEST IN PADDY CULTIVATION

1. Green leafhopper Nephotettix virescens

• Adults - are green with black spot and black patch on wings.

Symptom of damage

• Both nymphs and adults feed on rice by sucking the plant sap

• They migrate to the field soon after seedlings have emerged.

• Yellowing of leaves from tip to downwards. Vector for the diseases viz., Rice tungro virus, rice yellow & transitory yellowing

Yellowing Rice tungro virus

Management

• biological control :wasps parasitize the eggs. They are attacked by aquatic veliid bugs, nabid bugs, empid flies, damselflies, dragonflies, and spiders

• Use resistant varieties.• The vegetation on the bunds should also be sprayed

with the insecticides • Set up light traps

2. Rice case wormNymphula depunctalis

Larva Adult

Symptom of damage

• Caterpillars feed on green tissues of the leaves and leave become whitish papery

• Tubular cases around the tillers by cutting the apical portion of leaves

• Floating of tubular cases on the water

• Eg:Case tubes

Management

cultural control: • the use of correct fertilizer application, • wider spacing (30 × 20 mm)• early planting• draining the field• transplanting older seedlings• growing a ratoon can also help control this insect• dislodge the cases – running rope

biological agents: • snails are useful (predate on eggs), Spiders,

dragon flies, birds

Chemical control• larvae are highly sensitive to insecticides. • The use of foliar treatments-

carbamate• Pyrethroids should be avoided

3.Black bugScotinophara lurida

• The newly emerged adult is white and tinged with green and pink

• Mature adults are shiny dark brown or black.

Symptoms of damage

• Both the adults and nymphs remove the plant sap• They prefer the stem nodes because of the large sap

reservoirs• Black bugs feed on the rice plant from seedling to

maturity growth stages• Heavy infestation and “bug burn” is usually visible after

heading or maturing feeding damage of black bugs causes half-filled and empty grains.

• Ten adults per hill can cause losses of up to 35% in some rice.

Management• maintain a clean field by removing the weeds

and drying the rice field during ploughing• Direct-seeded rice crops tend to have less tillers

in one planting point and thus discourage population growth

• During early infestation, the water level in the field may be raised for 2-3 days to force the insects to move upwards.

• Flooding the fields can also cause higher egg mortality. After harvest, fields might be ploughed to remove remaining insects.

• In the field, there are biological control agents such as small wasps that parasitize the eggs.

• Ground beetles, spiders, crickets, and red ants attack the eggs, nymphs, and adults.

• Both the eggs and the nymphs are fed-upon by coccinellid beetles

Egg Larva Adult

4. Yellow stem borerScirpophaga incertulas

Symptom of damage • Presence of brown coloured egg mass near leaf

tip. • Caterpillar bore into central shoot of paddy

seedling and tiller• Causes drying of the central shoot known as

“dead heart” • Grown up plant whole panicle becomes dried

“white ear”.Dead heart White ear

Management

Cultural control• proper timing of planting and synchronous planting.• harvesting at ground level to remove the larvae in

stubble.• Ploughing and flooding • egg masses should be handpicked • The level of irrigation water can be raised

periodically to submerge the eggs deposited on the lower parts of the plant.

larvaAdult

5. Swarming caterpillar(Rice armyworm)

Spodoptera mauritia

Symptom of damage

• This pest attacks all stages of the rice crop• Larvae cut the seedlings in large scale • It becomes very destructive when the

population is high that it can totally devour the host plant

• Mature panicles are cut off from the base of the plants

• Severe infestation - cattle grazing appearance to the field.

Management

• Parasitoids such as tachinids, ichneumonids, eulophids, chalcids, and braconid wasps parasitize this pest

• Ants, ducks and birds feed on the pest. • Fungal diseases and viruses also infect the

larvae• Chemical control :when populations are

extremely high E.g Pyrethroids

Egg Adult

6. Gall midgeOrseolia oryzae

Symptom of damage

• Maggot feeds at the base of the growing shoot

• Causing formation of a tube like gall that is similar to “onion leaf” or “Silver-shoot”.

• Infested tillers produce no panicles.

Tuber gall

Management

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

• Optimum recommendation of potash fertilizer • Setup light trap and monitor the adult flies

Cultural control :• Ploughing ratoon of the previous crop• Harvest the crop and plough immediately • Use early maturing varieties • removing all off-season plant

Biological control: • The pupa is host to some species of wasps.• spiders eat the adults. • Resistant varieties

Eg: BG 304, BG 350• installing Light traps, • -Split application of Nitrogen fertilizers application of insecticide

(Eg : Carbofuran, Diaczinon)

7. Rice skipper Pelopidas mathias

• Larva: Pale green with constructed neck. • Adult: Butterfly with brown coloured wings

and curved antenna

Caterpillar Adult

Symptom of damage

• Edges of the leaves are fastened with webbing.

• Backward rolling of leaves,• caterpillar feeds from margin to inwards

Management

• Spray endosulfan 35 EC 1000 ml / ha or monocrotophos 36 WSC 500 ml / ha

Larva Adult

8. Leaf folder (or) leaf roller Cnaphalocrocis mainsails / Marasmia patnalis

Symptom of damage

• Leaves fold longitudinally and larvae remains inside.

• Larvae scrapes the green tissues of the leaves and becomes white and dry.

• During severe infestation the whole field exhibits scorched appearance

Longitudinal folding larva inside the fold white and dried leaves

Management

Cultural control• not use too much • Maintaining of surrounding grass habitatsBiological control• wasps and crickets attack eggs• larval and pupal stages :parasitized by many species of wasps• Damselflies, ants, beetles, wasps, prefer the larva

effective predator of rice leaf folder larvae.

Caterpillar Adult

Pupa

9. Green horned caterpillar Melanitis leda ismene

Damage

• Larva feeds on leaf blades of rice. • Leaves are defoliated from the margin or tip

irregularly.• minor pests of rice

Management

• Natural enemies usually control their populations and rice compensate from the feeding damage of green horned caterpillars

• Spray -Endosulfan -Monocrotophos

10. Mole cricket Gryllotalpa orientalis

• modified for digging• have strong teeth-like structures

Damage

• tunnels into the soil using its enlarged fore legs.

• It feeds on seeds and resulting in loss of plant stand or poor crop stands.

• It feeds on rice during the seed to seedling stages of the crop.

Management

Cultural control –• Maintaining standing water• Bund shaving and plastering of fresh wet soil• The rice field can be flooded for 3-4 days. • Modern varieties with long and dense fibrous can

tolerate damage betterBiological control-a sphecid wasp, carabid beetle, nematodes,

11. Yellow hairy caterpillar Psalis pennatula

• Larva -Caterpillar is yellowish brown with red stripes -Orange head and tufts of hairs all over the body. • Pupa -pale white cocoon of silk and frass attached to

the leaf • Adult -Moth is stout with straw coloured forewings.

Symptoms of damage

• Caterpillar causes defoliation

Management

cultural control :• draining the rice field for 3-4 days during the

early stage of infestation• Nitrogen application can be split to reduce

BPH build up• Synchronous planting within 3 weeks of

staggering and maintaining a free-rice period could also decrease the build-up of BPH.

Biological control :• Eggs are preyed upon by mirid bugs and phytoseiid

mites. • Nymphs and adults are eaten by spiders and

coccinellid beetles.

Resistant varieties:• A number of varieties with moderate level of

resistance to BPH have been developed• Bg 379-2, Bg 300, Bg 403, Bg 304, Bg 357, Bg 358, Bg

360 and 1. AT 402.

Chemical control:• Spray Endosulfan or Monocrotophos

12. Grasshopper Hieroglyphus banian

Short horned grasshopper Oxya nitidula

• Adults - Green, larger with transverse black lines on pronotum

Symptom of damage

• Irregular feeding on seedlings and leaf blade • Cutting of stem at panicle stage • Completely defoliate the plants leaving only

the mid ribs

Management

• Expose the eggs to be picked up by birds after ploughing and trim the bunds

• Dusting the crop with 5-10% BHC or methyl parathion 2% @ 25-30 kg/ha

• Dusting malathion 5% @ 20 kg/ha.

13. Spiny beetle / Rice hispaDicladispa armigera

• Larva - Grub is minute, flat and yellow • Adult - Blue - black shiny beetle with spines on

the thorax and elytra

Adult

Symptoms of damage

• Adults feed on chlorophyll by scraping and causing white parallel streaks

• White patches along with long axis of leaf. • Grubs mine into the leaves and make blister

near leaf tips.

white parallel streaksblister near leaf tips

Management

• Leaf tip containing blotch mines should be destroyed

• Manual collection and killing of beetles – hand nets

• Spray endosulfan 35 EC @1000ml/ha

14. Whorl maggot Hydrellia philippina

• Maggot - Yellowish white in colour.

• Adult - Small dull grey fly.

Symptom of damage

• Maggot feeds on the tender tissue inside the whorl

• Yellowish white longitudinal marginal blotching with hole

• Leaves shrivelled plant stunted and maturity delayed.

• Drooping of young leaves near the tip

Yellowish white blotching

Management

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

• Use early maturing varieties • Optimum recommendation of potash fertilizer • Small wasps parasitized the eggs and the

maggots. • The rice plant can compensate for the damage

caused by the rice whorl maggot.

15. Brown plant leafhopper Nilaparvata lugens

• Adult: Brown body and chestnut brown eyes. It has two forms viz.,

• (Macropterous (long winged) and brachypterous (short winged).

Symptoms of damage

• Nymphs and adults congregate at the base of the plant above the water level

• Affected plant dries up and gives a scorched appearance called “hopper burn”.

• Circular patches of drying and lodging of matured plant

• It is vector of grassy stunt, ragged stunt and wilted stunt diseases

Hopper burn Hopper burn

Management

cultural control • draining the rice field for 3-4 days during the

early stage of infestation• Synchronous planting within 3 weeks• Avoid close planting • Avoid use of excessive nitrogenous fertilizers• Control irrigation by intermittent draining• Set up light traps during night • Drain the water before the use of insecticides

Biological control :• Eggs are preyed upon by mirid bugs and

phytoseiid mites. • Nymphs and adults are eaten by spiders and

coccinellid beetles. Resistant varieties:• A number of varieties with moderate level of

resistance to BPH have been developed Bg 379-2, Bg 300, Bg 403, Bg 304, Bg 357, Bg

358, Bg 360 and 1. AT 402.

16. White backed plant hopper Sogatella furcifera

• Nymph - White in colour and pronotum is pale yellow.

• Adult - Possess a diamond like marking on the thorax and ovipositional site is black streaks.

Nymphs and adults

Damage

• Suck the sap and cause stunted growth.• “Hopper burn” is caused in irregular patches.

Management

• Avoid use of excessive nitrogenous fertilizers• Control irrigation by intermittent draining• Apply any one of the following • Monocrotophos• Carbofuran

17. Mealybug Brevennia rehi

• Adult - Small reddish white, soft-bodied • wingless insect covered with filamentous

materials.

Damage

• Large number of insects remains in leaf sheath and suck the sap.

• Plants become week, yellowish and very much stunted in circular patches.

• Presence of white waxy fluff in leaf sheaths

Management

• Durin field preparation - remove the grasses from the bunds and trim the bunds

• Remove and destroy the affected plants.• Spray any one of the following insecticides in

the initial stage of infestation – dimethoate – methyl demeton – Conserve the natural enemies like Scymnus

sp.,Anatrichus pygmaeus, and Mepachymerus ensifer

Adult

18. Paddy bug Leptocorisa acuta

Symptoms of damage

• Sucking the sap from individual grains, which are in milky stage.

• Individual grains become chaffy • Black spots on the grains at the site of feeding

puncture. • Buggy odour in rice field during milky stage

Eggs Black spots

Management

Cultural control • removal of alternate hosts • early planting • use of late-maturing cultivars. • Netting and handpicking the bugs reduce

their numbers.

biological control: • small wasps parasitize the eggs and the meadow

grasshoppers prey on them. • spiders• coccinellid beetles• dragonflies• use of entomopathogens

chemical control • Fenthoate • Cabaryl• Diacinon

19.Zigzag leafhopperRecilia dorsalis

• found in all rice environments• It is abundant during the early rainy season in

the early growth stages of the rice plant• adults usually stay in the upper parts of the

rice plants.

Zigzag leafhopper nymph adult

Management

• parasites and predators • Mymarid wasp and the mirid bug prey on the

eggs

20. ThripsStenchaetothrips biformis

• Adults - are dark brown in colour

Larvae Adult

Symptoms of damage

• Laceration of the tender leaves and suck the plant sap.• Yellow (or) silvery streaks on the leaves of young seedlings.

Terminal rolling and drying of leaves from tip to base It causes damage both in nursery and main field.

Initial - inward rolling silvery streaks

Management

Cultural control • Flooding to submerge the infested field for 2 days Biological control• Predatory thrips• coccinellid beetles• Avoid staggered cultivation Insecticide application: Dimethoate, Fenthion, Diacinon, Cabaryla

Group Members

• P.M.G.S.K.Attanayake AG/07/08/07• K.L.D.S.Chandradasa AG/07/08/14• K.P.N.K.Chandrasiri AG/07/08/15

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