Grapevine thrips is the most destructive pest in India.
It also damages other crops such as jamun, guava, mango, cashew nut, rose, etc.
It is active during March-May and September-October. Adults and nymphs feed by rasping on the ventral side of the leaves and flowers’ stalk and suck the oozing sap.
As a result of their intensive feeding, leaves develop silvery white scorches and gradually get deformed and fall down.
The attack on flower stalks result in flower shedding. The feeding on the developing berries results in scab formation.
Two speciesThere are two other species of thrips such as Scirtothrips dorsalis and Thrips hawaiiensis which exclusively attack blossoms and developing berries causing scarred fruits resulting poor quality and low price in the market.
The life cycle of this thrips is completed in 11 to 25 days according to weather conditions and there are five to eight generations in a year.
They undergo hibernations as pupae deep into the soil surface during winter. Young nymphs appear reddish and adults are yellowish brown. They reproduce both in sexual and parthenogenetic ways.
Integrated Management— Varieties of grapevine with thick and hairy leaves are known to be tolerant to thrips attack.
— Collect and destroy damaged leaves, fruits and flower.
— Install 10-13 blue / yellow sticky coloured sheets traps/ha
— Grow cowpea around the field bunds to conserve predatory coccinellid beetles.
— Raise eco-feast crops viz. castor, mustard, sunflower, marigold and coriander around the crop to conserve and encourage entomophagous insects.
— Spray beauveria bassiana at 5 ml or 5 g/lit under humid climatic conditions.
— Apply 500 ml of malathion or 1.5 kg of carbaryl 50 WP in 500 litres of water per 100 vines.
— Spray methyl demeton 25 EC at 2 ml/ lit, dimethoate 30 EC at 2 ml / lit, monocrotophos 36WSC at 1.25ml/lit, quinalphos 25EC at 1ml/lit, or ethion 50EC at 1ml/lit
(Dr. J. Jayaraj, Professor and Dr. M. Kalyanasundaram, Professor and Head, Department of Entomology, Agricultural College and Research Institute, Madurai 625 104, Phone: 0452-2422956 Extn.214, email: agentomac@tnau.ac.in)
