Rice crop insects damage and identification A Lecture By Mr Allah Dad Khan

RICE CROP INSECTS A PRESENTATION TO IPM COURSE/FFS PARTICIPANTS

BYMR. ALLAH DAD KHAN

PROVINCIAL COORDINATOR IPM KPK FOR MINFAL PAKISTAN

White backed plant hopper: Sogatella furcifera

Suck the sap and cause stunted growth

“Hopper burn” is caused in irregular patches

Ovipositional marks exposing the plant to fungal and bacterial infections

Ragged stunt or grassy stunt virus disease plant may be observed

Symptom of damage: Complete desapped plant

White backed plant hopper: Sogatella furcifera

Egg: Cylindrical eggs are laid in groups when the rice plant is small but in the upper part of the rice plant when the plant is large. (They are laid with the micropylar end protruding from the tissue, the operculum is long and narrow. The eggs in a group are not sealed together by the material secreted by female.)

Nymph: White to a strongly mottled dark grey or black and white in colour and 0.6 mm size when young. Fifth instar nymph with a narrow head and white or creamy white body. Dorsal surface of the thorax and abdomen marked with various amounts of grey and white markings.

Adult: The adult hopper is 3.5-4.0 mm long. The forewings are uniformly hyaline with dark veins. There is a prominent white band between the junctures of the wings. Macropterous males and females and brachypterousfemales are commonly found in the field.

Identification of insect pest: Nymph and Adult

Thrips: Stenchaetothrips biformis

Symptoms of damage: Leaf shows discoloration and

rolling 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 Leaf tips wither off when

severely infested Unfilled grains at panicle stage

Damage of Thrips in Nursery

Thrips: Stenchaetothrips biformis

Egg: Freshly laid egg is hyaline and turns pale yellow when about to mature. The egg is very tiny and measures 0.25 mm long.

Larva: Neonate larvae are transparent and towards the second molting, they turn to pale yellow. The legs, head, and antennae of the second instar larvae are slightly darker than those of the first instar larvae

Pupa: The pupa has long wing pads that reach two-thirds the length of the abdomen. It also has four pointed processes on the ninth abdominal tergite. The pre-pupa is brown. Four pointed processes are present on the hind margin of the ninth abdominal tergite.

Adult: The adult has a slender body. It is dark brown and 1-2 mm long. It exists in two forms, winged or wingless. The winged form has two pairs of elongated narrow wings that are fringed with long hairs.

Identification of insect pest: Nymph and Adult

Green leafhopper: Nephotettix virescens

Yellowing of leaves from tip to downwards

Vector for the diseases viz., Rice tungro virus, rice yellow & transitory yellowing cause direct damage to the rice plant

Retarded vigorous and stunted growth

Drying up of plant due to sucking up of the leaf

Symptom of damage: Yellowing

Green leafhopper: Nephotettix virescens

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.

Identification of insect pest: Adult

Rice case worm: Nymphula depunctalis

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

Cutting off leaf tips to make leaf cases

Symptom of damage: White scrapings on leaf due to feeding


Egg: Individual egg is circular, flattened, and measures 0.5 mm in diameter. It is light yellow and has a smooth surface. Mature eggs are darker and develop two purplish dots.

Larva: Pale translucent green with orange head. It has filamentous gills on the sides of the body. The larvae are found hanging from the leaf and measures upto 15mm long.

Pupa: The pupa is cream in color and about 5.5 mm long. Mature pupa is silvery white.

Adult: Moth is small, delicate white with pale brown wavy markings. The adult moth is about 5 mm long. It is bright white with light brown and black spots.

Identification of insect pest:


Adult Hydrophilid beetle preys caseworm larva

Paddy stemborer: Scirpophaga incertulas

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”

Plants could be easily pulled by hand

Symptom of damage:

Paddy stemborer: Scirpophaga incertulas

Egg: are creamy white, flattened, oval and scale like and laid in mass and covered with buff coloured hairs

Larva: pale yellow with dark brown head

Pupa: White silken cocoon are found inside the stem

Adult: Female moth: bright yellowish

brown fore wings with a black spot possess a tuft of yellow hairsMale moth: Smaller with pale yellow forewings without black spot


Chilo polichrysus

Larva Adult

Chilo suppressalis

Larva Adult

Scirpophaga incertulas

Larva Adult

Sesamia inference

Larva Adult

Swarming caterpillar: Spodoptera mauritiaSymptom

Larvae cut the seedlings in large scale

Cattle grazed appearance is found at severely infested fields

They feed gregariously and march from field to field

Symptoms of damage:


: Egg: eggs are spherical and creamy in

colour, which are laid in a group covered over with grey hairs

Larva: caterpillars are light green with yellowish white lateral and dorsal stripes in the early stages and later become dark brown or grayish green in colour with a crescent (semi-circular) shaped black spot on the side of each segment

Pupa: pupates in an earthen cocoon in soil. Pupa is dark brown and measures 16-17 mm long.

Adult: moth is medium sized, stout built dark brown with a conspicuous triangular black spot on the forewings. Hind wings are brownish white with thin black margins.

Identification of insect pest


Egg: eggs are spherical and creamy in colour, which are laid in a group covered over with grey hairs

Larva: caterpillars are light green with yellowish white lateral and dorsal stripes in the early stages and later become dark brown or grayish green in colour with a crescent (semi-circular) shaped black spot on the side of each segment

Pupa: pupates in an earthen cocoon in soil. Pupa is dark brown and measures 16-17 mm long.

Adult: moth is medium sized, stout built dark brown with a conspicuous triangular black spot on the forewings. Hind wings are brownish white with thin black margins.



pupa Adult

Gall midge: Orseolia oryzae

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.

Symptom of Damage Tube Gall

Gall midge: Orseolia oryzae

Egg: The fly lays elongate, cylindrical, shinning white or red or pinkish eggs singly or in clusters (2-6) at the base of the leaves.

Larva: Maggot is 1 mm long after hatching with pointed anterior end. It creeps down the sheath and enters the growing bud. An oval chamber is formed round the site of feeding.

Pupa: At the time of emergence the pupa wriggles up the tube with the help of antennal horn to the tip of the silver shoot and projects half way out.Adult: fly is yellowish brown and mosquito like. The male is ash grey in colour. Adults feed on dewdrops.


Rice skipper: Pelopidas mathias

Edges of the leaves are fastened with webbing

Backward rolling of leaves

Caterpillar feeds from margin to inwards

Symptom of damage: Floating of tubular cases around the tillers

Rice skipper: Pelopidas mathias

Eggs: are white or pale yellow and spherical. They are pearl-like in appearance.

Larva: The larval bodies of both species are green. They differ in the coloration on the head. One larva has reddish vertical bands at each lateral side of the head and the other one has brown bands that are closer together and W-shaped. The mature caterpillar measures 50 mm long.

Pupa: The pupae of both species are light brown or light green. They have pointed ends.

Adult: The adults of the two species are light brown with orange markings and white spots on the wings. They can be distinguished by the pattern of white spots on the wings. One adult has seven C-shaped white spots on the front wing and four white spots on the hind wing. The other one has four small spherical white spots and two elongated spots on the front wing and the hind wing lacks spots

Identification of insect pest: Larva and adult

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

Leaves fold longitudinally and larvae remains inside

Larva scrapes the green tissues of the leaves, becomes white and dry

During severe infestation the whole field exhibits scorched appearance

Symptom of damage: White and dried Leaves


Egg: Flat, oval in shape and yellowish white in colour

Larva: Greenish translucent

Adult: Moth is brownish with many dark wavy lines in centre and dark band on margin of wings.



Rice horned caterpillar: Melanitis ismene

Larva feeds on leaf blades of rice.

Leaves are defoliated from the margin or tip irregularly

Symptom of damage:

Rice horned caterpillar: Melanitis ismene

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Yellow hairy caterpillar: Psalis pennatula

Caterpillar causes defoliation

Symptoms of damage:


Egg: yellow coloured pubescent eggs are found in groups on leaf surface

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



Caterpillar Adult

Grasshopper: Hieroglyphus banianShort horned grasshopper: Oxya nitidula

Irregular feeding on seedlings and leaf blade

Cutting of stem at panicle stage

Completely defoliate the plants leaving only the mid ribs

Symptoms of damage:

Grasshopper: Hieroglyphus banianShort horned grasshopper: Oxya nitidula

Eggs: 30-40 yellowish eggs are laid in groups and covered with gummy like substance

Nymph: Nymphs feed on grasses and paddy

Adults:

Identification of insect pest : Grass Hopper

Spiny beetle: Rice hispa, Dicladispa armigera

Tunneling through leaf tissue causing irregular translucent white patches that are parallel to the leaf veins

Adults feed on chlorophyll by scraping and causing white parallel streaks

Grubs mine into the leaves and make blister near leaf tips.

Damaged leaves fall down At server infestation, field looks

like burnt appearance.

Symptoms of damage:


Egg: Eggs are laid inside minute slits on the tender leaves generally toward the tip

Larva: The grub is whitish yellow and flattened. It feeds inside the leaf tissue by mining. It pupates inside

Adult: The adult beetle is somewhat square shaped about 1/6 to 1/8” in length and width. Dark blue or blackish in colour with spines all over the body.



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Whorl maggot: Hydrellia sasakii

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

Symptom of damage:

Whorl maggot: Hydrellia sasakii

Egg: White, cigar shaped egg laid singly on either side of the leaves

Grub: Newly hatched larva is transparent to very light cream in colour but later become yellow. The larvae move down the leaf into the whorl on a film of dew and feed within developing whorls. The larvae mostly remain outside the leaves and feed on the mesophyll tissue of the foliage. When leaves emerge from the whorl damage can be seen as pinholes in the leaves and white and yellowish lesions on the leaf edge.

Pupa: Pupation takes place in between the leaf sheath where the pupa is loosely attached to the stem. The puparium is light to dark brown ovoid and sub-cylindrical in shape.

Adult: Adult dark grey flies, 1.8-2.3 mm in size

Identification of the pest: Adult Pupa Larva

Mealybug: Brevennia rehi

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

Symptom of damage: Symptom of Mealybug Infestation

Mealybug: Brevennia rehi

Egg: The female lays numerous yellowish white eggs/ simply deposits nymphs in outer leaf sheaths.

Nymph: The newly hatched nymphs crowded within the waxy threads for 6-10 h before they disperse to various parts of the same plant. The pale yellowish nymph is active and crawls about the plant for a while and settled itself on the plant/ stem and turns dark yellow after a day. Body gets covered with waxy material on second day.

Adult: Nymphs and adults being wingless look alike. Females are reddish, oval, soft-bodied living in colonies inside the leaf sheath. Males are small, slender, pale-yellow, having single pair of wings and a style like process at the end of the abdomen but lack mouthparts. Males are seldom found in the colonies, so it reproduces parthenogenetically.

Identification of insect pest: Mealy bugs

Rice earhead bug: Leptocorisa acuta

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

Symptoms of damage:

Rice earhead bug: Leptocorisa acuta

Egg: Are circular, brownish seed like 2mm long laid in clusters in two rows along the midrib on the upper surface of the leaf blade

Nymph: First instar is small, 2mm long, pale green in colour which grows to deepen green through different instars

Adult: Adults are greenish yellow, long and slender, above ½ inch in length with a characteristics buggy odour


Education

Rice crop insects damage and identification A Lecture By Mr Allah Dad Khan