February 2008. Damage caused by Red palm weevil can be devastating in dates. A member from India wanted to know whether neem, Azadirachtin, can control this pest. Is there any success reported? If not, are there any successful biological control measures available?
Good orchard hygiene is best; to a large degree the pest is one of neglected orchards which then spreads as the RPW fly out. Effective trimming of leaves at the stem and, after a couple of week attraction (using pheromones) of the laying females, effective disposal of the trimmings, are all important. It is possible to cut the leaves a bit further away from the stem than usual, females lay their eggs and then the leaves are trimmed again. This increases work, of course. Avoid damage to the trees and, when de-suckering, fill the damage holes with clay.
Biological control is best with pheromone traps, which are quite effective.
Azadirachtin – problem would be keeping a long term deterrent effect against a pest that is difficult to reach in the stems; same problem with fungi and nematodes. Some people think it’s possible to treat around the stems with nematodes or fungi; if done systematically it would probably work.
So, good field hygiene and waste management is the answer; avoid wounds and repair those that occur in the trunks (the leaf cutting damage is unavoidable though); pheromone traps, used properly – right number, replaced as necessary.
Legislate to avoid absentee landowners – where the most neglected plantations are. However, the absentees tend to be the rich and powerful so legislation could be a problem!
Also, a copy of the recommendations of a meeting was sent as an attachment: Recommendations of the International workshop on Red palm weevil control strategy, Spain, Elche, 23-24 April 07.
Note that the infested offshoots are a very quick means to introduce the pest to non-infested area. Therefore, phytosanitary control is very important in the strategy of this serious pest.