Disease : Rhinoceros beetle

This is the most important pest belonging to the group popularly known as cockchafer beetle.

  • Rhinoceros Image1
  • Rhinoceros Image2
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  • The beetle causes harm by boring in to the unopened tender fronds (spindle),spathe and leaf petioles.
  • The beetle bites the fibrous portion, chew the juice and throws out the dry fibrous mass.
  • This mass is commonly seen covered in the burrow made by the beetle and also in the leaf axils.
  • When the central spindle is attacked it breaks at the point of attack and the functional leaf area of the frond is reduced considerably.
  • Damage to the spathe reduces the yield. Petiole damage results in breaking of the whole fronds.
  • Injury caused by the beetle may lead to secondary infestation by red palm weevil; and infection by pathogenic microbes.
  • Seedling when attacked is killed.
  • When growing point is cut, as it sometimes happens, the tree suffers seriously and in some cases dies off.

Procedure for Observation

Look for the damaging symptoms from twenty trees selected at random from a plot and record the number of trees showing damage.


2 trees

Control Measures

  • Destroy the early stages of the insect incorporate Clerodendron infortunatum namely grub and pupae. For this in cow dung pits/manure pits.
  • Inoculate breeding sites with Metarrhizium anisopliae @ 20 g per litre of water.
  • Spray the fluid in manure pit with regular inversion of the manure. This will result in the mortality of grubs.
  • Provide field sanitation to prevent breeding of beetles.
  • Treat manure pits and other possible breeding sites with carbaryl 50 WP/ at one g in 5 lit. of water.
  • Treatment will have to be repeated every three months if found necessary.
  • Hook out the beetle from the affected palms using beetle hook.
  • Top most three leaf axils around the spindle are to be filled with any one of the following mixtures.
  • 250 g neemcake or Marotti cake mixed with equal volume of sand in the innermost 2-3 leaf axils.
  • This treatment has to be done twice a year viz. during April to May before the onset of monsoon and during September to October after South West monsoon.
  • For easy application the mixture may be taken in a 750 ml bottle with long neck.