ENTO 331 :: Lecture 01 :: Pest of Rice

PESTS OF RICE :: Major Pests :: Mealy Bug

6. Mealy bug: Brevennia rehi (Pseudococcidae: Hemiptera)

Distribution and Status: Tamil Nadu, Andhra Pradesh, Karnataka, Orissa, Madhya Pradesh, West Bengal and Kerala in India, Bangladesh, Thailand

Host range: Rice, graminaceous weeds

Damage symptoms: Large number of insects remains in leaf sheath and suck the sap, affecting plants in circular patches. Plants become weak, yellowish and stunted. Presence of white waxy fluff in leaf sheath is a typical symptom of damage.

Field damage caused by mealy bugs (IRRI)

Bionomics: The mealy bug is small reddish white, soft-bodied, wingless insect covered with filamentous materials. It lays 126-139 eggs in the leaf sheath and reproduces parthenogenetically. The egg period 1-2 days; nymphal period 17-34 days, nymphs remain within the leaf sheath and suck the plant sap.

Management
1. Parasitoids such as Adelencyrtus sp., Xanthoencyrtus sp. and Dolichoceros sp. and coccinellid predators can be utilized.
2. Remove the grasses and trim the bunds during the main field preparation before transplanting.
3. Remove and destroy the affected plants.

4. Spray dimethoate 30 EC 500 ml/ha in initial stages of infestation.