Management of red palm weevil, Rhynchophorus ferrugineus (Olivier), in palm agro-ecosystems: An overview

Globally, red palm weevil (RPW), Rhynchophorus ferrugineus Olivier, (Curculionidae/ Rhynchophoridae/Dryophthoridae), attacks 17 palm species in diverse agro -ecosystems. It has its home in South and South–East Asia where it is a key pest of coconut, Cocos nucifera and is reported from 15 per cent of the coconut growing countries world wide. During the mid nineteen eighties it gained foot hold in date palm Phoenix dactylifera plantations of the Middle East and has since then caused wide spread damage to date plantations in the region. Reports suggest that nearly 50 per cent of the date growing countries are currently infested by RPW. By mid nineteen nineties this pest, was reported from Africa on date palm in Egypt from where it moved in to Europe (Spain) through infested planting material and is now a major threat to the Canary island palm, Phoenix canariensis in several Mediterranean countries. Currently, only the American continent is free from this lethal pest. Often, injury to the palm due to shaving of fronds and removal of off shoots (date palm) pre disposes the crop to attack by attracting female weevils for egg laying. RPW is managed in several countries using area-wide pheromone based integrated pest management (IPM) programmes. Due to the high value of the palm species involved and the hidden and lethal nature of this pest, action thresholds for initiating control of RPW are low. At the individual farm level infested palms need to be treated on priority, while area–wide RPW-IPM programmes are initiated at a level of one per cent infestation and require substantial investment over a period of time. However, the key to the success of any RPW-IPM strategy lies in the early detection of infested palms which respond to treatment with insecticide (stem injection). Palms in the late stage of attack, often harbor several overlapping generations and usually donot respond to chemical treatment.