Rice, the staple diet of over half of the world's population, is grown on over 145 million ha in more than 110 countries, and occupies almost one-fifth of the total world cropland under cereals. Classified primarily as a tropical and subtropical crop, rice is cultivated as far north as 53° N latitude on the border between the USSR and China and as far south as 39° S latitude in Central Argentina, and from sea level to altitudes of 3,000 m. The crop is established either by direct sowing (broadcast or drilled) or by transplanting. Rice grows under diverse water regimes: it is an upland crop where there is no standing water and rains are the sole source of moisture, or a lowland crop under conditions in which water, derived either from rain or irrigation systems, is impounded in the fields. Rice is cultivated on terraces, on slopes, and in valleys or other lowlying sites. Floating rice may be grown in several meters of standing water. Most of the world's rice production is from irrigated and rainfed lowland ricefields where insect pests are constraints. The warm and humid environment in which rice is grown is conducive to the proliferation of insects. Heavily fertilized, hightillering MVs and the practice of multicropping rice throughout the year favor the buildup of pest populations. The intensity of the insect problem in such an area can be illustrated by the experience at IRRI. In 117 experiments conducted over 15 yr, plots protected from insects yielded almost twice as much as unprotected plots.Average rice yield loss due to various insect pests was estimated to be 31.5% in Asia (excluding mainland China) and 21 % in North and Central America in 1967. 1 Estimates for tropical South and Southeast Asia are considerably lower. In a 1989 survey of 50 rice entomologists from 11 countries, average yield losses due to insect pests were estimated at 18.5%. Yield increases of this magnitude frequently result from effective insect control in the different South and Southeast Asian countries. The rice plant is subject to attack by more than 100 species of insects; 20 of them can cause economic damage. Together they infest all parts of the plant at all growth stages, and a few transmit viral diseases. The major insect pests that cause significant yield losses are leafhoppers and planthoppers, which cause direct damage as well as transmit viruses; stem borers; and a group of defoliator species.

1. Borer and defoliator
pests of rice
By
Dr. U. Pirithiraj, P.hD.
Assistant Professor (Entomology)
JSACAT
Affiliated to Tamil Nadu Agricultural University

2. Borers pests of rice

3. Paddy stem borer, Scirpophaga incertulas,
Pyraustidae, Lepidoptera
Symptoms of attack
Vegetative stage, dead hearts Reproductive stage, white ear
1
Distribution: Afghanistan, Nepal, north-eastern India, Sri Lanka, Bangladesh, Burma, Vietnam, Thailand,
Malaysia, Singapore, Sumatra, Java, Borneo, Sumba, Sulawesi, the Philippines, Taiwan, China and Japan.
Dr. U. Pirithiraj, P.hD. (Entomology)

4. Eggs are creamy white. Each egg mass
consists of 15-80 eggs and covered with
buff coloured hairs.
The hatched larvae move downward
They may hang down by a sliver thread and get to other plants
with the help of the wind.
They can also swim over the water and reach other tillers.
They enter the leaf sheath and feed upon the green tissues of the
stem for 2-3 days.
Generally only one caterpillar is seen inside a tiller. It may come
out and attack fresh tiller.
The full-grown caterpillar measures about 20 mm, white or
yellowish white in colour with a conspicuous prothoracic shield.
Dr. U. Pirithiraj, P.hD. (Entomology)

5. Pupation takes place inside the rice
stem, straw or stubble. Before
pupation it make a exit hole in the
internode and covers it with a thin
web for the adult to come out later.
The female moth is bright
yellowish with a black
spot at the centre of the
forewing and a tuft of
yellow hairs at the anal
region.
The male is small in
size and brownish.
Dr. U. Pirithiraj, P.hD. (Entomology)

6. Pink rice borer, Sesamia inferens,
Noctuidae, Lepidoptera
Dark headed borer, Chilo polychrysus,
Crambidae, Lepidoptera
Striped rice borer, Chilo suppressalis,
Crambidae, Lepidoptera
White rice borer, Scirpophaga innotata,
Pyraustidae, Lepidoptera
Dr. U. Pirithiraj, P.hD. (Entomology)

7. Pink rice borer, Sesamia inferens,
Noctuidae, Lepidoptera
Dark headed borer, Chilo polychrysus,
Crambidae, Lepidoptera
White rice borer, Scirpophaga innotata,
Pyraustidae, Lepidoptera Dr. U. Pirithiraj, P.hD. (Entomology)
Striped rice borer, Chilo suppressalis,
Crambidae, Lepidoptera

8. ETL: 10% Dead heart symptoms 2% white ear symptoms
•Clip the seedling tips before transplanting to eliminate egg masses.
•Install light trap @ 1 / ha and pheromone trap @ 5/ac or 12/ha.
•Release egg parasitoid, Trichogramma japonicum @ 2cc /ac 3 times at weely interval.
•Spray Neem seed kernel extract 5% or Azadirachtin 0.03% 400 ml/ac.
•Spray any one of the following insecticides
• Acephate 75 % SP 267-400 g/ac, Carbofuran 3% CG 10 kg/ac, Carbosulfan 6% G 6.7
kg/ac, Carbosulfan 25% EC 320-400 ml/ac, CartapHydrochloride 50 % SP 400 g/ac,
Chlorantraniliprole 18.5% SC 60 ml/ac, Chlorantraniliprole 0.4% G 4 kg/ac,
Chlorpyriphos 20% EC 500 ml/ac, Fipronil 5% SC 400-600 g/ac, Fipronil 80%WG 20-25
g/ac, Flubendiamide 20% WG 50 g/ac, Flubendiamide 39.35% M/M SC 20 g/ac,
Thiacloprid 21.7% SC 200 g/ac, Thiamethoxam 25% WG 40 g/ac
Dr. U. Pirithiraj, P.hD. (Entomology)

9. Paddy gall midge, Orseolia oryzae, Cecidomyiidae,
Diptera
Maggot bores into the growing point of the tiller
and causes abnormal growth of the leaf sheath,
which becomes whitish tubular and ends bluntly
Further growth of tiller is arrested. This is called
onion shoot, silver shoot or anaikomban.
The feeding by the maggot and the larval secretion,
which contains an active substance called cecidogen,
is responsible for cell proliferation of the meristematic
cells and gall formation.
Symptoms and nature of damage
2
Distribution. It is a major insect pest of rice in Southern and Southeast Asia.
Dr. U. Pirithiraj, P.hD. (Entomology)

10. Elongate, cylindrical, pinkish
eggs singly or in clusters (2-6)
at the base of the leaves
Maggot is 1 mm long, enters the
growing bud, oval chamber is
formed around the site of feeding
The pupa projects half
way out at the time of
emergence .
The adult fly is yellowish to
orange brown and
mosquito like. The male is
ash grey in colour.
Dr. U. Pirithiraj, P.hD. (Entomology)

11. Management
ETL: 10% silver shoots
•Release Platygaster oryzae parasitised galls at 1/10
sq.m on 10 days after transplanting (DAT)
•Harvest the crop and plough immediately
•Remove the alternate hosts and adopt early planting
•Setup infra red light trap and monitor the adult flies
•Spray any one of the following insectcides
• Phosalone 35 EC 600 ml/ac
• Fipronil 5% SC 400-600 g/ac
• Thiamethoxam 25% WG 40 g/ac
Dr. U. Pirithiraj, P.hD. (Entomology)

12. Defoliators

13. Swarming caterpillar, Spodoptera Mauritia,
Noctuidae, Lepidoptera
Caterpillars march in large numbers in the
evening hours and feed on the leaves of
paddy seedlings till the morning and hide
during daytime.
Under severe infestation crop gives the
appearance of cattle grazed plants.
Nature/ Symptom of attack
3
Distribution. India, Myanmar, Sri Lanka, Malaya to Australia and widespread in the Pacific Islands
Dr. U. Pirithiraj, P.hD. (Entomology)

14. Eggs are spherical and
creamy in colour
Later become dark brown or
grayish green in colour with a
crescent (semi-circular) shaped
black spot on the side of each
segment
The caterpillars are
green with yellowish
white lateral and
dorsal stripes
Dr. U. Pirithiraj, P.hD. (Entomology)

15. They pupate inside the soil in earthen
cocoons. Pupa is dark brown and
measures 16-17 mm long.
A conspicuous triangular black
spot on the forewings and white
hind wings with brown margins.
Dr. U. Pirithiraj, P.hD. (Entomology)

16. Management:
•Flood the nursery to expose the hiding larvae to the surface for birds to pick
them up.
•Allow ducks into the field to feed on the larvae.
•Dig trenches around the infested field and place ashes in the trenches to
make it difficult for the larvae to escape.
•Insecticides should be the last resort for armyworm control.
•In nursery, drain the water and spray chlorpyriphos 20 EC @ 80ml + 20 lit of
water for 8 cents.
•In main field, spary Chlorpyriphos 20% EC @ 500 ml/ac during late evening in
case of severe infestation.
Dr. U. Pirithiraj, P.hD. (Entomology)

17. Rice case worm, Nymphula depunctualis,
Pyraustidae, Lepidoptera
Leaves of plants are eaten by the larvae, which remain within
small cylindrical leaf cases and are seen hanging on the
leaves. Leaf cases found floating on water.
4
Distribution and Status: India, South East Asia, Australia
Dr. U. Pirithiraj, P.hD. (Entomology)

18. The larva is light green with a light
brownish-orange head. (18-22 days)
Eggs are pale, yellowish green, laid
in one or two long rows on under
surfaces. (4-6 days)
Pupates inside the case 5-6 days Moth is immaculate white with light brown and
black spots on the wings
Dr. U. Pirithiraj, P.hD. (Entomology)

19. Management:
•ETL–2 FDL/hill (FDL- Fully Damaged Leaf)
•The pest is semi aquatic and hence draining is the most effective
method for the management of the pest.
•Dislodge the cases by passing a rope and then drain water; collect
the cases and destroy.
•Maintain field and bunds weed free. Do early planting and follow
wider spacing.
•Encourage biological control agents like hydrophilid and dytiscid
water beetles which feed on larvae and spiders, dragonflies, and
birds which feed on adults.
Dr. U. Pirithiraj, P.hD. (Entomology)

20. Rice skipper, Pelopidas mathias, Hesperidae,
Lepidoptera
Nature of damage
Larva feeding from margin inwards
Symptom of damage
Defoliation
5
Southeast Asia and Philippines
Dr. U. Pirithiraj, P.hD. (Entomology)

21. Adult: Brown coloured wings with white spots
on the wings.
Eggs: laid singly on the leaf blades. Larva: pale green with constricted neck. Red ‘V’
mark on the head
Pupa: Light green
Dr. U. Pirithiraj, P.hD. (Entomology)

22. Management
•Parasitoids and predators usually control skippers in nature in the field.
•Eggs of rice skippers are parasitized by small wasps. The orb-web spiders
feed on the adults during flight.
•A nuclear polyhedrosis virus also infects skipper larvae.
•Drain the water and spray chlorpyriphos 20 EC 500 ml/ac.
Dr. U. Pirithiraj, P.hD. (Entomology)

23. Leaf folder/ roller, Cnaphalocrocis medinalis,
pyralidae, lepidoptera
6
Damage symptoms
• Roll up leaf blades.
• Feed by scrapping the chlorophyll.
• Leaves dry up
• Sporadic pest
Distribution: All the rice growing tracts of humid
tropical and temperate countries in Asia, Oceania,
Australia and Africa
Dr. U. Pirithiraj, P.hD. (Entomology)
Silk strands attached to leaf margins

24. Egg: Flat, oval in shape and yellowish
white in colour, laid undersurface of the
leaves. 3-5 days
Adult: Orange brown moth with many dark wavy
lines in the center and dark band on the margins
of wings. 7 days.
Larva: Pale green,
transparent, actively
moving caterpillar.
22-28 days
Pupa: Pupates in the base of
the leaf fold. 7-10 days
Dr. U. Pirithiraj, P.hD. (Entomology)

25. Management:
ETL: 10% leaf damage at vegetative phase and 5% of flag leaf damage at flowering
•Release Trichogramma chilonis @2 cc (40,000/ac) thrice at 37, 44 and 51 days
•Avoid excessive nitrogenous fertilizers
•Keep the bunds clean
•Spray NSKE 5 % or Azadirachtin 0.03% 400 ml/ac
or
•Spray any one of the following insectcides
• Phosalone 35 EC 600 ml/ac, Chlorpyriphos 20 EC 500 ml/ac, Acephate 75 %
SP 267-400 ml/ac, Carbosulfan 6% G 6.7 kg/ac, CartapHydrochloride 50 % SP
400 g/ac, Chlorantraniliprole 18.5% SC 60 g/ac, Chlorantraniliprole 0.4% G 4
kg/ac, Fipronil 80%WG 20-25 g/ac, Flubendiamide 39.35% M/M SC 20 g/ac,
Flubendiamide 20% WG 50-100 g/ac, Thiamethoxam 25% WG 40 g/ac
Dr. U. Pirithiraj, P.hD. (Entomology)

26. Rice horned caterpillar, Melanitis ismene,
Nymphalidae, Lepidoptera
Symptom of damage
Defoliation along margins & tips
7
Distribution: Africa, South Asia and South-east Asia extending to parts of Australia
Dr. U. Pirithiraj, P.hD. (Entomology)

27. Shiny eggs (4 days)
Large light green larva with horns in head and
elongated processes in the tip of abdomen (27 days)
Chyrsalis
suspending from
leaves (10 days)
Dark brown adults
with eye spots in
wings
Dr. U. Pirithiraj, P.hD. (Entomology)

28. Management
The eggs are parasitized by trichogrammatid wasps.
Chalcid wasp and two species of tachinid flies parasitize the
larvae and a vespid wasp preys on the larvae.
Spraying nuvan 100 EC @ 200 ml/ha (or) malathion 50 EC@
2.5 lit/ha.
Dr. U. Pirithiraj, P.hD. (Entomology)

29. Yellow hairy caterpillar, Psalis pennatula,
Lymantriidae, Lepidoptera
Nature of damage : Larva feed on leaves
Symptoms of damage : Defoliation
8
Distribution: India, Sri Lanka, Thailand, Australia
Dr. U. Pirithiraj, P.hD. (Entomology)

30. Yellow coloured pubescent eggs are
found in groups on leaf surface
Yellow brown with red stripes and tuft of hairs all
over body
Pale white cocoon
Moth is stout and straw-
coloured with longitudinal
dark band on fore wings.
Management:
Spray the crop with chlorpyriphos 20 EC 500 ml/ac
Dr. U. Pirithiraj, P.hD. (Entomology)

31. Grass hoppers, Hieroglyphus banian (Large grasshopper)
Oxya nitidula (Small grasshopper), Acrididae, Orthoptera
Rice grasshoppers feed throughout
the year on rice, maize, millet,
sugarcane and other grasses
Polyphagous pest
Damage : Caused by both adults and
nymphs. Both nymphs and adults
feed the leaves from margin inwards.
9
H. banian is widespread throughout India and Pakistan
Oxya sp. - Asia, Africa,. Northern Africa, and Algeria
Dr. U. Pirithiraj, P.hD. (Entomology)

32. Female lay eggs in soil. The eggs are laid 5-8 cm deep in pods each containing 30-40 eggs
O. nitidula - green, smaller with
brown band on lateral sides of
thorax
H. Banian - green, larger with
three transverse black lines
on pronotum.
Dr. U. Pirithiraj, P.hD. (Entomology)
Management:
Cut the soil with a spade or rake and plaster the lands especially in rice field and water channels
to destroy the egg pods.

33. Spiny beetle/ Rice hispa, Dicladispa armigera,
Chrysomelidae, Coleoptera
Nature of damage
Leaf mining by grubs and scrapping by
adults
Symptoms of damage
Narrow white lines in leaves due to leaf
mining.
10
Distribution: Bangladesh, India, and Laos.
Dr. U. Pirithiraj, P.hD. (Entomology)

34. Pupa - inside leaf mines (5 days)
Small shiny blue / black beetle
recognized by numerous short
spines on the body.
Eggs embedded in leaf tissues
near leaf tips (4-5 days)
Flat yellowish grubs with
brown heads (7 -12 days)
Dr. U. Pirithiraj, P.hD. (Entomology)

35. Management
Leaf tip containing mines should be destroyed.
Manual collection and killing of beetles – hand nets.
To prevent egg laying of the pests, the shoot tips can be cut.
Reduviid bug eats upon the grubs.
Spraying insecticides
Dr. U. Pirithiraj, P.hD. (Entomology)

36. Whorl maggot, Hydrellia sasakii, Ephydridae,
Diptera
Nature of damage
Maggot feeds on the tender tissue inside the
whorl
Symptoms of damage
Dicoloured longitudinal blotches, Shriveling of
leaves
ETL
25%
Damaged
leaves
11
Distribution and status: Philippines and India
Dr. U. Pirithiraj, P.hD. (Entomology)

37. Grey to black fly
1.8-2.3 mm in size
Small, Elongate Cigar
shaped, Laid singly on
leaves (2 – 6 days)
Light cream to yellow. (10 – 12 days)
Pupates outside feeding stalk.
(5 – 10 days)
Dr. U. Pirithiraj, P.hD. (Entomology)

38. Blue beetle, Alticia cyanea, Chrysomelidae,
Coleoptera
12
Harmless and breeds on weeds
Dr. U. Pirithiraj, P.hD. (Entomology)

39. Root Feeders

40. Rice root weevil, Echinocnemus oryzae,
Curculionidae, Coleoptera
Damage symptoms
Grubs feed on the roots of rice plants
resulting in stunting and non formation of
tillers.
Presence of dead plants in large patches
is a typical symptom.
Bionomics: Adult weevil is shiny black
with greyish scales.
13
Dr. U. Pirithiraj, P.hD. (Entomology)

41. Rice root weevil, Hydronomidus molitar,
Curculionidae, Coleoptera
Damage symptoms: Yellowing of newly
transplanted seedlings and presence of dead
plants in large patches.
Bionomics: Adult is shiny black weevils with
oblong body covered with greyish scales.
14
Dr. U. Pirithiraj, P.hD. (Entomology)

42. Rice root grub, Arthrodeis sp., Tenebrionidae
Coleoptera
Damage symptoms: They feed on roots and cause yellowing and gradual wilting
of entire plants.
Bionomics: Black coloured shiny beetle.
Harvester termite, Anacanthotermes viarum
(Hodotermitidae: Isoptera)
15
16
Dr. U. Pirithiraj, P.hD. (Entomology)