INDIA IS the largest producer of sugarcane and sugar in the world. The woolly aphid C.lanigera has become a serious pest in almost all the sugarcane growing areas of the country.

Nature of damage:

The pests suck the sap from the cane, leading to stunted growth. A waxy secretion results in yellowing of leaves. Copious amount of honeydew excreted covers the entire upper surface of the leaves leading to growth of sooty mould, which ultimately inhibits photosynthesis. Continuous infestation leads to reduction in the length, circumference, weight and sugar content of the cane.

Factors responsible

Active movement of nymph is the primary cause of dispersal within and between fields. Wind plays the major role in spreading of the aphids. The ants attracted to the honeydew excretion also carry the nymphal stages of the aphids from one field to another. Transportation of infested cane and planting of setts with infested leaves should not be done.

Natural enemies

Releasing 2,500 eggs of Chrysoperia carnea or larvae per hectare of green lacewing can be helpful in checking the aphid population .

Management

- Do not use infested seed material for planting.- Regular monitoring of the field at least once in a week with special emphasis on crop under shaded areas.- Movement of infested seed material, green leaves or trash from infested area should be avoided.- Spacing between the beds should be one metre or wide enough for a person to walk and carry out the spraying operations.- Apply nitrogenous fertilizers at recommended dose.- Remove alternate host like Cynodon dactylon (weed) prevents the breeding of the pest in off-season.J. MAHENDRA KUMAR

Agricultural Research Station
Siruguppa, Bellary
Karnataka