JASMINE (Jasminum sambac) known as `gundu malli' in Tamil Nadu is attacked by a number of pests which cause considerable damage. Among them red spider mite, Tetranychus urticae, is gaining importance due to prevailing drought and hot weather.
In jasmine, flowering commences during March-April and comes to peak in May-July. During this period, the weather is too hot and is favourable for multiplication of this mite population.
The mites are tiny eight-legged arthropods. Eggs are laid on the underside of leaves. An adult female can lay more than 100 eggs in three weeks.
Eggs hatch in four to five days and the entire life cycle from egg to adult is completed in one to three weeks, depending on the temperature.
During summer, mite populations increase quickly.
Mites are typically found on the undersides of leaves, but may colonise entire plants during outbreaks.
The mites suck sap from cells on the underside of plant leaves, in the early stages and characteristic white speckles can be seen from the upper leaf surface.
As mite numbers increase these white speckles also increase and the leaf exhibits a bleached appearance.
In case of severe infestation, the whole plant becomes pale in colour, and affects production and size of the flower buds.
Such buds fetch a low market price. Silk webbing on the undersides of leaves are characteristic signs of spider mites.
Red spider mite can be controlled by spraying with either dicofol 18.5 EC at 2 ml/litre or wettable sulphur at 50WP 2g/litre.
Two sprays should be given at 15 days interval. Repeated spraying of the same chemical should be avoided.
As the infestation by T.urticae and the jasmine leaf webber, Nausinoe geometralis coincides with the flushing stage, application of profenofos against leaf webber will also check the pest.
Department of Agricultural Entomology