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The Red Palm Weevil (Rhynchophorus ferrugineus - Olivier)

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A serious pest of palms in the Mediterranean area.
The red palm weevil is a member of Coleoptera: Curculionidae. The male and female adults are large reddish brown beetles about 3 cm long, with a characteristic long curved rostrum. Having strong wings they are capable of undertaking long flights.

The insect first appeared in Arabian Peninsula and very soon was spread in the southern Asia North Africa and recently in the Mediterranean area. It infests all types of palm trees of economic importance such as Coconut palms, oil palms and also ornamental palms.

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Damage to palms is made mainly by the larvae. Adult females lay about 200 eggs at the base of the young leaves or in wounds to the leaves and trunks; the grubs feed on the soft fibers and terminal bud tissues. They reach to a size of more than 5 cm before pupation. Except just before pupating, they move towards the interior of the palm making tunnels and large cavities. They can be found in any place within the palm, even in the very base of the trunk where the roots emerge. Larval period is long, varies from 2 to 3 months. Pupation occurs generally outside the trunk, at the base of the palms. Pupation takes place within a cocoon made of brown dried palm fibre under the bark and lasts 14 - 21 days. The total life cycle is completed in 4 months.
The red palm weevil can lead to a devastating damage to palm plantations and total destruction of the production of economic important crops. Usually the damage caused by the larvae is visible only long after infection, and by the time the first symptoms of the attack appear. Damage is very serious and generally results to the death of the tree. This late detection of the presence of the weevil constitutes a major problem in the fight against the pest and in any attempt to guarantee pest-free status in adult trees.

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Pheromone application

Specially designed traps loaded with an aggregation pheromone dispenser of the red palm weevil are used to determine population level in localized zones. This trap is also useful for mass trapping in large or small groves.
The traps are placed in the specific area during the first flight period of the beetle or as advised by an agronomist. Place on the ground near the trunk of the palm or on the trunk of the palm at a height of 1,5-2,0m .

Monitoring: The recommended trap density is 1-2 traps per hectare depending on the density of the plantation. By counting the number of insects caught, the user gets information about the flight activity and the population density. An IPM program can therefore establish. If the traps stay empty there is no need for further treatment with insecticides.

Mass Trapping: Application of 4-8 traps per hectare can significantly reduce the active population of the insect and minimize or even eliminate the use of chemical insecticides for the control of this devastating pest.

Lures
The basic lure is an aggregation pheromone dispenser, loaded with 600 mg of active ingredient known under the name of ferruginol. VIORYL's dispensers contain also a powerful synergistic food attractant in the same formulation.
It is recommended to add in the trap a small recipient (about 50 ml) containing a 15% aqueous solution of sugar can molasses.
Both lures have to be changed every 6-8 weeks depending of the average temperature of the area where traps have been placed.

 

Afidnes, August 2008