Insect Pests of Fruit, Plantation, Medicinal & Aromatic Crops (2+1)

5. Thrips Scirtothrips bispinosus Bagn. (Thripidae: Thysanoptera)

Damage

• Both nymphs and adults lacerate and suck the tender leaves.
• Due to the punctures caused by stylets the feeding site appear as brown spots or as continuos lines called "sand paper lines" In severe cases of infestation leaf growth is arrested, leaves become brittle, crinckled and corky and fall prematurely.
Bionomics

• S. dorsalis - This is known as Assam thrips, causes severe damage to tea bushes in North India.
• Its life cycle is completed in 13-17 days but the duration may vary in the different seasons. S. bispinosus -
• This is yellowish brown in colour which is found in large numbers in most tea growing areas of south India.
• The peak period for the population build up is between May and December.
• This life cycle is completed in 19 days.