Cultural, biological and chemical control of stem borer in paddy

Morphology & identification

• Eggs are laid near the tip on the upper surface of tender leaf in small masses, covered with a felt like buff coloured mass of hair and scales

egg mass at leaf tip

   Favorable conditions  

• ★  Cold weather, high humidity and 
•   low temperature in October-December are favourable
• ★High nitrogen

 Nature of damage

• ★Newly hatched larvae which are pale white with dark brown head and prothoracic 
• ★shield, move downward and wander about on plant surface for 1-2 hours. They hang 
• ★down by silk thread, get blown off to other clumps or land on water, swim freely and get 
• ★to the plants. They enter leaf sheath and feed on green tissues for 2-3 days, then bore into the stem near nodal region to feed

Symptom of damage

• ★“Dead-heart” at vegetative stage which turns brownish, curls and dries off “White ears” at heading stage with empty, partially filled grains Presence of egg masses near the tips of tender leaf bladesActivity of moths in the vicinity Frass at the feeding site

Dead hearts  at                 white ears at panical stage

Vegetative stage

Management;

Cultural methods

• Harvesting of crop close to soil surface, ploughing or flooding the field after harvest to kill hibernating larvae in the stubbles
• Clipping the tips of the seedlings prior to transplantation aids in the elimination of egg masses
• Setting light traps or pheromone traps for monitoring the pest
• Collection and elimination of egg masses

Biological control

Chemical methods

Need based application of insecticides on ETL basis

Nursery : 1 egg mass or 1 moth / m2• Main crop : 1 egg mass or 1 moth / m2, 5% dead head 1% white ears

Nursery 

1. 5 days before pulling the nursery application of carbofuran 3G @ 200 g/cent of nursery in a little water (seedling root-dip not required)(or)
   
2. Foliar sprays with monocrotophos 1.6 ml/l or chlorpyriphos 2.0 ml/l at 10 and 17 DAS

Main field