Symptoms:

The damage usually more pronounced on new vegetative flush. Yellowish grubs feeding on tender leaves through mining are seen as whitish blotches causing twisting and rolling.  The main damage is caused by female D. marginatus, which cuts young leaves. The most obvious symptom of attack by this pest is presence of young leaf bits below the tree.  Stripped shoots can be easily seen on the infested plant from distance. Adult feeding produces “Windowpanes” on young leaves.  Heavy clustering of weevils is observed in the apical portion of new flush.  The weevils are very active and fly away quickly if any slight disturbance is there.

Infested tender shoots become almost leafless. The damage is severe in nurseries and young plantations, where often the seedlings die or growth inhibition was noticed in young plantations.  Weather conditions such as intermittent rains with warm weather can lead to outbreak of this pest.

Control

·         Spraying of insecticides such as Deltamethrin (1 mL/L) or Cypermethrin (0.5 mL/L) or Carbaryl (4 g/L) during new leaf emergence can effectively prevent the weevil damage. 

·    Close monitoring has to be carried out during spraying as these weevils can fly away and stay on the neighbouring plants (orchards) and can return later to cause enormous damage.