Managing red palm weevil in coconut
RED PALM weevil (Rhynchophorus ferrugineus) is a major pest of coconut plantations in India. Once the palm is attacked it succumbs to the infestation in 6 to 8 months if timely control measures are not adopted. The infestation is more severe in young plantations.
Stem infestation
As the leaf axils are soft they provide congenial sites for oviposition of red palm weevil.
In the palms subjected to toddy tapping, the steps cut or wounds made on the tender stems for climbing purpose and broken or cut petioles also invite the adult weevils.
In the affected trees, holes are seen with exudation of a thick brownish viscous fluid and extrusion of chewed up discarded fibres.
Crown infestation
Infestation on the spindle leaves or an incidence of fungal diseases like bud rot or leaf rot lead to the attack of red palm weevil in many cases
The eggs are usually laid in fresh wounds or injuries on the coconut palm. The apodous (absence of legs) grub bores into the interior of the palm, feeding voraciously on the inner soft succulent tissues.
Larval period ranges from one to two months. At the end of the larval period the grub makes an elongated, oval cocoon made out of fibrous strands and pupates inside.
The total life is completed in four months. Adults are reddish brown with a long, curved and pointed snout.
The damaged palm should be destroyed, and mechanical injuries on trees should be avoided.
The crown of the palm should be kept clean and tidy
Root feeding with moncrotophos at 10ml plus 10ml of water is effective. After root feeding up to 45 days nuts must not be harvested.
The weevil infested palms can be saved by the application of Endosulfan or carbaryl at 0.1 per cent.
G. BALAKRISHNAMOORTHY
& D. VIJAYALAKSHMI
Department of Spices and Plantation Crops
Tamil Nadu Agricultural University
Coimbatore, Tamil Nadu
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