Moringa oleifera is famous as a vegetable used in southern Indian dishes due to its unique taste and medicinal properties and it is also a highly renumerative commercial crop for farmers.
A specific pest called leaf eating caterpillar Noorda blitealis earlier considered as a minor pest usually infests the crops during during December-January over south India, and is causing serious problems because of its high population buildup.
Females lay creamy, oval eggs on leaves, which hatch in 2-3days. Larvae feed on leaflets in a thin silken web on the lower surface.
The leaves appear papery and get dried. If left untreated, the whole tree is defoliated. Grown-up larvae pupate in the soil. An adults emerge in 6-9 days and life cycle continues.
Severe infestation occurs on new flush of the crop during June-August which later recedes.
It is advisable to go for collection and destruction of leaves with silken webs and caterpillars in the initial stages of infestation.
The young larvae feed voraciously on the foliage and strip the branches completely. The moths are medium sized, having forewings with rectangular, apex with erect outer margin and uniformly dark in colour with small white streak at the inner area of base.
Adult moths may be collected through light traps and destroyed.
Hand picking of larva in early stages may be effective in reducing population built-up.
Provision for sitting arrangement for birds above the height of the moringa crop in field enabling the birds to visit and prey them.
One to two sprays of Malathin (2ml/lit) can be applied to reduce infestation. Dichlorvos (0.04 per cent) and Fenthion (0.05 per cent) were found effective in combating the pest.
Regional Research Station
National Horticultural Research & Development Foundation, Kadapa District