The coconut palm weevil causes major economic damage to coconut trees, especially the dwarf varieties. It causes the young leaves to turn yellow and die. It can spread red ring disease and mites. The weevils bore in to oil palm and trunks of coconut trees and feed on them. An infested tree grows slowly and the crown or tip of the palm starts to wilt. The young and mature nuts drop, green branches fall off and the young clusters dry up.
The adult female weevil lays eggs between the branch and the bunch on the living tree. The eggs hatch into larvae (worms) that tunnel inside of the tree destroying the tubes which help transport plant food. They develop (pupate) and emerge as adults and fly to infest other trees. These weevils can lay up to 700 eggs in 60 days. They are most active early in the morning and late in the afternoon. The number of weevils is greatest in the dry season.
- Manual control involves catching and destroying the weevils by hand. The infested trees are cut down and infested regions chopped in smaller sections. The beetles and larvae are collected and destroyed.
- Trapping the beetles is most effective method used with the use of a chemical compound to attract mainly the male weevils.
How to make a bottle attractant trap:
Collect three 2 Litre cola plastic bottles or similar.
- Remove the neck and bottom of one bottle to make a tube and only the neck of another.
- Cut a window 2 inch square in the side but near the base of a third bottle (without removing the neck or bottom) join all three bottles together as seen in the photo (the whole bottle with the window at the top tube in middle and bottle with neck removed at the bottom) and seal with tape. Use tape on edges of window.
- Place small bits of split sugarcane in the trap to attract the weevils. If available add pheromone for the pest (make a pin size hole in the packet without emptying its content) and use tape to attach to the inside of trap to attract the weevil. Place trap within the crown of the palm tree. Check trap every 2 days. Kill the weevils caught by crushing (outside the trap) and keep a record of the number caught.