ENTO 331 :: Lecture 01 :: Pest of Rice

PESTS OF RICE :: Major Pests :: Rice Earhead Bug

5. Rice earhead bug: Leptocorisa acuta (Alydidae: Hemiptera)

Distribution and status: India and rice growing areas

Host range: Rice, Millets

Damage symtoms: Both nymphs and adults suck the sap from individual grains at milky stage. Affected grains become chaffy with black spots at the site of feeding puncture. Yield loss may be 10- 40%. Obnoxious odour emanates on disturbing the bugs in the field.

Damaged grains caused by
rice bug (IRRI)

ETL: 5 bugs/100 panicles or 1 bug/hill - flowering stage; 16 bugs/100 panicles or 3 bug/hill- milky stage.

Bionomics: Brownish green adults are slender with long legs and antennae, lay 200-300 flat, dark, reddish brown eggs in rows of 10-15 on the leaves or panicles. The egg period 5-8 days, green to brown nymphs undergo five instars in 17-27 days. Adults fairly long lived (30-50 days).

Management

Remove alternate host, Echinocloa from bunds and field.
Ensure synchronous planting on community basis in an area.
Use neem seed kernel extract 5% or notchi leaf powder extract 5% or Ipomoea leaf powder extract 5% or
Prosopis leaf powder extract 5%.
Dust quinalphos 1.5 D or carbaryl 10 D or malathion 5 D @ 25 kg/ha or spray
malathion 50 EC 500 ml or monocrotophos 36 WSC 500 ml/ha.