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PESTS OF SORGHUM :: Major Pests :: Earhead Bug


5. Earhead bug: Calocoris angustatus (Miridae: Hemiptera)

Distribution and status: South India 

Host range: Pearl Millet, maize, tenai, sugarcane and grasses

Damage symptoms: The adults and nymphs damage the earheads by feeding on them. They suck the juice from the grains when they are in the milky stage. The sucked out grains, shrink and turn black in colour and become ill filled (or) chaffy.  Older grain shows distinct feeding punctures
that reduce grain quality.


 

Bionomics: Adult male is green in colour and female is green with a brown margin.  Blue cigar shaped eggs are laid under the glumes or into the middle of the florets.  Each insect lays between 150 and 200 eggs.The egg period is seven days.  Nymphs are slender, green in colour.  First instar is orange in colour.  The nymphal period is 10 - 14 days.  The life cycle from egg to adult occupies less than 3 weeks. At least 2 generations of the bug can feed on the same crop when the panicles do not ripen at the same time.


ETL: 10 Nos/ear head.


Management 

    • Dust with carbaryl 10% at 12 kg/ha (or) quinalphos 1.5% 12 kg/ha synchronising during  milky stage
    • Grow resistant cultivars like IS1760, IS 17645, CSM 388, Chencholam, BBR -1(ICS V239)