Crop stage and pest

Economic threshold levels

A. Nursery

1. Green leaf hopper

1-2 insects/m2

2. Gall midge

1 silver shoot (gall)/m2

3. Stem borer

1 moth or 1 egg mass/m2

4. Blast

5% disease severity

B. Planting to pre-tillering

1. Leaf folder

2 freshly damaged leaves/hill

2. Yellow stem borer

10% dead hearts or one egg mass or one moth/m2

3. Gall midge

1 gall/m2 in endemic areas or 5% affected tillers in non-endemic areas.

4. Brown plant hopper

5 to 10 insects/hill

5. Green leaf hopper

10 insects/hill (in RTV endemic areas 21 insects/hill)

6. White backed plant hopper

10 insects/hill

7. Rice Hispa

2 adults or 2 damaged leaves/hill

C. Mid-tillering

1. Leaf folder

2 freshly damaged leaves/hill

2. Stem borer

10% dead heart or 1 moth or 1 egg mass/m2

3. Gall midge

10% silver shoots

4. Brown plant hopper

10 insect/hill

5. Green leaf hopper

10-20 insects/hill

6. Hispa

2 adults or 2 damaged leaves/hill

7. Blast

Light (5-10% disease severity)

8. Bacterial blight

Light (2 to 5% disease severity)

9. Sheath blight

10% or more affected tillers

10. Tungro

1 affected hill/m2

D. Panicle initiation to booting

1. Stem borer

1 egg mass or 1 moth/m2

2. Leaf folder

2 freshly damaged leaves/hill

3. Green leaf hopper

20 insects/hill

4. Brown plant hopper

15 to 20 insects/hill

5. White backed plant hopper

15 to 20 insects/hill

6. Blast

5 to 10% leaf area damaged

7. Bacterial blight

Light to moderate (2-5% disease severity)

8. Sheath blight

10% or more tillers affected

E. Flowering and after

1. Brown plant hopper

25 to 30 insects/hill

2. Climbing cutworm

4-5 larvae/m2

3. Rice bug

1 or 2 bugs/hill

4. Blast

5% leaf area damaged or 1 to 2% neck infection

5. Sheath rot / brown spot / slight panicle discolouration

2-5% tillers affected

6. Sheath blight

10% or more tillers affected

7. Stem borer

2% white ear head