Disease and pest infestation forecasting station :

Heavy infestation of Brown plant hopper (Nilaparvata lugens Stal.) and rice bug (Leptocorisa acuta Fabr.) in rice in coastal saline belt of West Bengal.

Date: 1^st October to 15^th October, 2011

Possibility of the Insect pest :

Highest level of infestation was observed in the field which in many cases crossed ETL. Proper management need to be taken without further delay.

Diagnostic summary :

Brown plant hopper: Brown colour, small size nymphs and adults suck sap from basal portion of the hill just above the waterline. As a result infected plants looks like burning in appearance.

Rice Bug: The nymphs and adults having very bad and offensive smell suck juice from the developing grains in the milking stage and cause chaffy or black spotted incompletely filled grains.

Economic threshold level (ETL):

Brown plant hopper: 5-10 insects / hill

Rice Bug: 1-2 bugs/hill

Factors favouring development:

Brown plant hopper:

·                    Cultivation of high yielding varieties

·                    Lack of sufficient light and air at the basal portion of each and every hill.

·                    Presence of continuous water in the field

·                    high levels of nitrogen fertilizer

Management at this particular moment:

Brown plant hopper:

1)                  Reduce or delay top dressing of nitrogenous fertilizers and apply in 2 or 3 split doses.

2)                  Spray Thiamethoxam (@ 0.20 gm/l), Imidachloropid (@ 0.14 ml/l), Acetamiprid (@ 0.20 ml/l) at the base of the plant

Rice Bug:

1)         100 gm vermin meat + 100 gm molasses + 8-10 drops Chloropyriphos or Phosphamidon      in a cloth bag will have to keep at the same level of panicle by a stick. Approximately 15-20 such bags are required for 1 bigha.

2)         Spray carbaryl (@ 2.5 gm/l) or Chloropyriphos (@ 1.50 ml/l) or Dichlorovos (@ 0.75 ml/l) or cartap hydrochloride (@ 1.00 gm/l).