Three species of mango hoppers namely Idioscopus niveosparsus, Idioscopus clypealis and Amirtodus atkinsoni are serious pests in the entire mango growing regions of India.
They remain active throughout the year but the incidence is severe during the months from February to April.
Infested flowers shrivel, turn brown and ultimately fall off. Besides feeding injury, the hoppers also excrete honey dews on which black mould develops that interferes with photosynthesis and arrests new shoot development.
Poor fruit set
These damages result in weakening of the plants, reduction in fruit set and premature dropping of fruits, leading up to 60 per cent yield loss.
Egg laying starts from February to March. Each female lays around 150 eggs, laid singly by inserting into florets and stalk of the inflorescence. The eggs hatch in 4 to 7 days. Freshly hatched nymphs are white and gradually turn yellowish-green. They undergo 4-5 moultings in 10-13 days and become adults which are light greenish-brown in colour with black and yellow markings.
There may be 2-3 generations during the blossoming period. Adult hoppers are found all through the year hiding on the bark of the tree.
Management
Avoid close planting and prune dense orchards during winter for better light interception. Keep the orchard clean by regular ploughing and removal of weeds.
Collect and destroy affected inflorescence.
Spray Carbaryl at 2gm/lit, Phosalone 1.5ml/lit, Etofenprox 0.03 per cent, acephate 75 SP at 1gm/lit, or imidacloprid 0.2ml/lit twice in February and March.
The first spray should be given during flower formation stage and the second, two weeks after the first spray.
Wettable sulphur at2 gm/lit may be sprayed after spraying carbaryl to avoid mite resurgence.
(J. Jayaraj, Prof and R. K. Murali Baskaran Professor and Head, Dept. of Agrl. Entomology, Agricultural College and Research Institute, Madurai 625 104, email: vu2jrj@rediffmail.com, Phone:0452-2422956 Extn.214)
