BLACK BUGS, AS A PEST OF RICE

Chairman Dr. G. RAVI

Associate Professor (Entomology),

Tamilnadu Rice Research Institute,

Aduthurai.

Members Dr. S. MOHAMED JALALUDDIN

Professor (Entomology),

Tamilnadu Rice Research Institute,

Aduthurai.

Dr. A. KARTHIKEYAN

Professor (Plant Pathology),

Tamilnadu Rice Research Institute,

Aduthurai.

Presented by S. Venkatesh babuji

09-602-011

Introduction

• Rice – Important staple crop (>65% in world)

• More than 75 species of insect pest

• Black bug – also an important pest (Ooi, 1981)

Black bugs

• Greenish or pinkish rounded eggs

• Brown or yellow nymphs

• Brownish black to black adults

• Sucking bugs cause serious damage

• Damage symptom – similar to BPH

• Highly attracted towards light

• Emits pungent odor

Taxonomy

Order : Hemiptera

Suborder : Heteroptera

Family : Pentatomidae

Genus : Scotinophara Stal

Species : before = 41 species

now = 60 - 71 spp.

Common Names:

Rice black bug, Malaysian black bug, Node-feeding black bug, Japanese black bug

Two Major sp i.e. S.coarctata and S.lurida

(Ooi, 1981)

Species Differences S. coarctata (Fabricius)

S. lurida (Burmeister)

Species complex

• S. parva

• S. tarsalis

• S. scotti

• S. harvathi

• S. inermiceps

• S. latiuscula

• S. affinis

• S. inermis

• S. ochracea (Reissig et al., 1986)

More…

(Anthony, 2010)

Species Complex

• 11 spp. were common in rice field.

• In India

• S. coarctata Fabricus (Pathak. M. D, et al., 1994)

• S. lurida Burmeister

• S. bispinosa Fabricus

• S. scottii Hovarth

• S. westwoodi Westwood (Ravi et al., 2008)

Species Complex

• In Cauvery delta zone

• S. lurida Burmeister (96%)

• S. bispinosa Fabricus (2%)

• S. scottii Hovarth (1%)

• S. westwoodi Westwood (1%)

Species identified by Heinrichs, IRRI (Ravi et al., 2008)

Black bug in rice production

• Occurrence - First recorded in 1903 (Pathak et al., 1994)

• In Malaysia - 1920s (Corbett and Yusope, 1920)

• 1979 at Phillipines.

• Its entry to india – lacks evidences (Saroja et al., 1993)

• Entry into Tamilnadu recorded in Tiruchirapalli Dt.,

(Uthamasamy. S, 1985)

Habitat

• Abundant in ill drained rice fields.

• Population is low under rainfed conditions and increases with expanded irrigation (Anon., 1983)

• Bugs were sluggish in day time and active in night (Pathak et al., 1994)

• Day time - Adult congregate at base of plants just above the water level

• Night time - Move upwards and sucks the sap

• Crowding was high – full moon day. (Abdul Latif et al., 1982)

• Aestivate in soil (Ravi et al., 2008)

Biology

• Life cycle - 37 days.

• Longivity - 203-210 days

• Female lays 200 eggs in its life span

• Egg - hatch in 4-7days. (Jalaluddin et al, 2010)

• Oviposition - 12-14 days after mating

• Egg mass contains – 40 – 60 eggs (Wilma et al., 2007)

• 90% hatchability (Magsino, 2009)

Egg

• Laid in masses (40-60 eggs in several parallel rows).

• Dry conditions - bug deposits its eggs on the leaves and stem.

• Also laid in cracks on the soil and on roots.

• Egg incubation is 4 to 7 days.

Nymphs

• Brown and yellow coloured (Reissig et al., 1986)

• 5 nymphal instars - 29-35 days

• Feeds at night

Adults

• Oval-shaped and about 8-9 mm long

• Lives for upto 7 months

• Female lays about 200 eggs

• Guards the eggs until hatching (Reissig et al., 1986)

Biology S. No Stage Min

(days) Max

(days)

1 Eggs in egg mass 40 60

2 Row in egg mass 3 5

3 Hatching % 65 90

4 hatching 4 7

5 I Instar nymph 4 6

6 II instar nymph 6 8

7 III instar nymph 6 8

8 IV instar nymph 7 10

9 V instarnymph 8 10

10

Adult longevity 203 210

(7 months)

(Saroja et al., 1993)

(Ravi et al., 2008)

(Magsino et al., 2009)

(Wilma, 2007)

(Jalaludin et al., 2010)

• Pakistan Philippines

• India Indonesia

• Srilanka (Anon, 1976)

• Bangladesh

• Burma

• Thailand

• Vietnam

• Malaysia

(Corbett and Yusope, 1924)

Distribution

India

China

Vietnam

Japan

Malaysia

Phillippines

Indonesia

Pakisthan

Bangladesh Burma

Distribution

• 1903 – Indonesia

• 1918 – West Malaysia

• 1933 – Thailand

• 1940 – Sri Lanka

• 1967 – East Malaysia

• 1975 – Vietnam

• 1977 – India

• 1979 – Philippines

1903

1918

1933

1940

1967

1975 1977

1979

(Magsino, 2009)

Distribution in Tamilnadu

• Trichy

• Tirur, Tirunelveli

• Vellore

• Thiruvarur, Nagapattinam, Thanjavur (Ravi et al., 2008)

Population Dynamics

• Light trap catches were high in full moon week

(Anon, 1985)

• Study on RRS, Tirur in 1992 elucidate that

• 80 watts black light have high performance than 125 watts, 200 watts, and 40 watts M. V. lamp

(Saroja et al., 1993)

Rice Technology Bulletin, 2000

Population dynamics - ADT

Month Catches(Nos.)

April 09 7077

May 0

June 15

July 0

August 24,890

September 93

October 46

November -

December -

January 10 330

February 3395

March 2380

(Ravi et al., 2008) and (Jallaluddin et al 2010)

Environment favorable for RBB • Irrigated wetland environments

• Vegetative stages of the rice plant

• Continuously cropped irrigated rice areas

• Poorly drained fields

• Densely planted fields

• Presence of alternate hosts/plants

• Lunar phase

(Rice Knowledge bank, IRRI)

Feeding

• Both nymph & Adult feeds base of plant.

• Desaping– predominantly from culm and also from leaf sheath, leaves and panicle.

• Preferred sites stem nodes

• Reservoirs of sap - meet out feeding requirement.

Alternate host

• Zea mays L.

• Colocasia esculenta Schott.

• Hibiscus esculentus L

• Vigna unguilanta L.

• Weeds, Hymenachne pseudointerrupta

• Panicum amplexicaule Rudge Pl. Guian.

• Scirpus grossus L.

• Scleria sumatrensis Retz.

• Typha angustfolia

• Echinochloa crus-galli

(IRRI , Rice Knowledge bulletin)

Damage

• In Phillipines

• Production loss 2.2 million 1992 (Fernandez ,1993)

• 10,000 ha of rice field in 1995 (Apao et al., 1998)

• 6,202 ha in Leyte provinces in 2000 (Tempo, 2004)

Damage

• Tiruchirapalli dt black bug regularly affect 800 ha Uthamasamy. et al., 1985

In Cauvery delta zone (100% loss)

• In summer 2006 Paruthikottai ( Tanjore) 4 acre

• In Andalam pettai 6 acres 2005

• Tsunami bugs

Susceptible stages of Infestation

Damage

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

Barrion, 2010

Damage

Damage

• Drying of leaf from the tip

• Reddish brown or yellow

Dead heart

• At early stage of attack.

White ears

• At late stage of the crop period.

Magsino, 2009

Damage

• Plant stunting & reduced tiller number

Damage

• Incomplete and unfilled spikelets at crop maturation

Bug Burn

• Heavy attack ultimately leads to Bugburn

Differentiation between Stem borer and Black bug damage

• The deadheart/ white ear damage caused by black bug cannot be pulled at the bases.

• Deadheart/ white ear in all the plants in a hill

• The symptom “bugburn” occurs, but No honeydew deposits or sooty molds.

Anonymous 2010. Rice Knowledge Bank, IRRI

www.knowledgebank.irri.org

Bugs/hill and the yield

(Saroja et al., 1993)

Economic Threshold Level

• Economic Threshold Level 6 bugs / Hill

• Economic Injury Level 3 bugs /Hill (Heinrichs et al., 1987)

Management

• Time of planting

• Standing crop

• During Outbreaks

• At harvest time

Management

• Summer ploughing reduce the black bug population that present in the weeds and stubbles of the land

(Zahirul Islam, 2006)

Ploughed and unploughed land

Days after plough

Bugs No.

(Shepard et al., 1987)

Management

• Trimming of Bunds Reduces the alternate hosts and hiding places of black bugs

• Sanitation crop sanitation is very important

(Zahirul Islam, 2006)

Management • Selection of Varieties

• Moderately resistant

• IR1314 and IR44526

• CO 37

(IRRI Rice Knowledge bank)

• Moderately susceptible

• ADT 37, TKM 1, TKM 2, TKM 10

• Susceptible

• ADT 38, ASD 16, ASD 17, CO 45, IR 20

• Highly susceptible

• ADT 36, TKM 9, CO 43, IR 50

(Saroja, 1993)

Varietal screening

Management

• Synchronous planting with same maturity

• Same maturity in large contiguous area with regular gap between season

• Use early maturing variety Rice Technology Bulletin, 2000

Management

• Crop rotation

• Rotation with the non-prefered crop will distrubs the lie cycle

Zahirul Islam, 2006

Management

• Direct seeded rice (highly recommended in endemic areas)

(Zahirul islam, 2006)

(IRRI Rice Technology Bulletin, 2000)

Management

• wider spacing (Avoid Dense planting)

• Rouge space - for effective monitoring

• Crop background - Azolla covering enhance the activity of natural enemies – assisting their movement from hill to hill

Dry season vs wet season

(Mochida et al., 1986)

Management

• Water management

• Alternate flooding minimize the RBB significantly

• RBB population was high in 2cm water level than 10 cm water level

(Tadle F.P.J, 2002)

• Higher water level - submerge the egg mass and reduce the hatchability

(Barrion T, 2010)

Management

• Fertilizer management

• High N levels increases RBB incidence (Pathak. et al., 1994)

• Use of Neem coated urea.

• Leaf Colour Chart.

• N in split doses (Jalaluddin et al., 2010)

Management

• Predatory Birds

• Bird perches

• Black drongo, Dicrurus adsimilis

• Herding of Ducks (Zahirul Islam, 2002)

Light trap

• Install light traps in areas nearer.

• Use 20 watt fluorescent tube.

• 5 m above ground.

• 6 p.m. to 6 a.m.

• Kill the catch and bury it in soil (IRRI Rice Technology Bulletin ,2000)

• Setting up 1 tap /5 acre. (Ravi et al., 2008)

Management - Out brakes

• Mass trapping with light traps

• high intensity light (2000-3000 watts)

• mounted on 5-10m high bamboo pole

• Super light covers a 5km radius. (Rice Technology Bulletin, 2000)

Natural enemies

Natural Enemies

• Wasp (Telenomus triptus) egg

• Metarhizium anisopliae (Cahatian et al., 2000)

• Beauveria bassiana

• Ground beetle - Agonium daimio

• Spider - Lycosa pseudoannulata, Oxyopes javanus, Tetragnatha virescens

• Cricket - Tetragnatha virescens

• Red ant - Solenopsis geminata

• Coccinellid beetle - Micraspis crocea

• Damsel bug – Stenonabis tagalicus

(Rice Technology Bulletin, 2000)

Management

• Insecticides • Raise the water level-bugs to the top or the spraying at the

base of the plant

(Parducho ,1988)

• Monocrotophos 36 SL (500g a.i. /ha) reduce the black bug population most effectively

(Subramanian et al., 1986)

• Acephate 75SP @ 625 g/ha

• Chloripyriphos 20EC 1250 ml ml/ha

• Dichlorvos 76 WSC 625 ml/ha

(Jalaluddin et al., 2010)

Sprays and leaf damage

(Saroja et al., 1993)

Sprays Leaf damage

Control 78.1 %

NSKE 5% 31.0 %

Neem oil 3% 47.9%

Acephate 28.4%

Monocrotophos 30.7 %

Management

• Light trapping - newly harvested area.

• Submerging stubbles – until decompose

• Cut up to the base (Rice Technology bulletin, 2000)

• Ploughing with raised water level.

• Submerge and plough the field to kill eggs, nymphs and adults.

(Barrian, 2010)

CONCLUSION

Discussion