Expert146;s tips on managing mealy bugs in fruit plants

In all, six species of mealy bugs are causing loss to different fruit plants namely citrus, guava, grapes, pomegranate, chiku, jamun and aonla in Punjab.

In all, six species of mealy bugs are causing loss to different fruit plants namely citrus, guava, grapes, pomegranate, chiku, jamun and aonla in Punjab.

Giving details, fruit entomologist Dr DR Sharma said that the nymphs and adult females of these mealy bugs sucked cell sap from different parts of the plant like leaves, twigs, tender shoots, branches and fruits thereby reducing the vigour of plant as well as the drying up the tender shoots. Heavy infestation encourages the growth of sooty mould due to which the leaves, shots and fruits become black in colour, said Dr Sharma. adding that all mealy bugs hibernate on the twigs and branches of trees during winter. It is important to identify the different mealy bug species on different plants, he advised.

The mealy bugs of fruit crops may not be confused with one infesting the cotton crop though the cotton mealy bug is reported to shift to citrus plantation but its development on citrus plantation is yet to be established. Furthermore, it is important to note that mango mealy bug may also not be confused with other mealy bug species.

In the case of citrus, guava and grapes, PAU has recommended: monitor regularly the infestation of trees by observing the underside of leaves, young shoots, fruits and branches; maintain the orchards neat and clean; do not allow the branches of trees to touch the ground; prune or remove the infested branches and destroy the same; destroy the ant nests in the orchards and drench spraying of 1875ml urmet/Dursban/Coroban 20 EC chlorpyriphos in 500 litres of water first on the appearance of pest and repeat the spray, if required.

On mango trees, mealy bug may be managed by digging or ploughing around mango trees during summer to kill the hibernating eggs as well as by the application of mechanical barrier through which the nymphs are prevented from crawling up the trunk by applying a slippery band as a mechanical barrier by mid-December.

The slippery band consists of 15-20 cm wide sheet of alkathene to the basal end of the stem and secures both its upper and lower edges with 1-3 nails 2 cm. The lower end should be covered with compact soil so as to prevent nymphs from climbing up the tree trunk.

Occasional wiping of the band during rains is also desirable. In case of a large-scale emergence of nymphs, apply 50 gm Follidol 2 dust methyl parathion on the compact soil around the tree trunk to kill the nymphs. The slippery band is effective in this case due to the fact that this mealy bug hibernate in soil as compared to other mealy bugs on other fruit crops.