Red weevil, that fearsome plague treatment

Rhynchophorus ferrugineus  ( red palm weevil ) carries out its biological cycle inside the palm tree, so in most cases we only become aware of the palm tree when it already has physical symptoms. There are a number of guidelines for identifying palm invasion. We will see these keys below.


The fact that the weevil carries out all of its biological cycles inside the palm tree gives it protection and adaptability to different geographical areas. Of the different varieties of the genus Palmae, a higher incidence is observed on  Phoenix spp , specifically in  Phoenix dactylifera L.  and  Phoenix canariensis.

Life cycle of the red palm weevil

To identify the presence of the red palm weevil, this symptom appears:

  • External leaves drooping, with evidence of tearing and gnawing at the end of new leaves.
  • Presence of fibers in the soil as a result of the excavation of galleries by the larvae.
  • Appearance of collapse or decay of the leaves.
  • Presence of galleries in the pruned palms.

Next, different forms of treatment, physical, chemical and biological against the red palm weevil are mentioned.


Pruning is a fundamental practice for the cleaning and sanitation of the palm tree. Excessive pruning should be avoided at all times, especially green palms, since these, when the cut is made, release pheromones (kariomone) that are attractive to the red palm weevil.

The goal of pruning should be the removal of old or dead leaves. Pruning or brushing of the stipes (trunk) should be avoided to avoid the production of pheromones and the complete elimination of pruning by burning or burying them.


One technique used as prevention is to apply an extra dose of nutrients and risks. Although this practice will not prevent the invasion of the palm weevil, it can delay the damage in order to carry out a detection and treatment with the different control methods.




The main drawback of this pest is due to the fact that the weevil carries out its entire biological cycle inside the palm tree. An external treatment (foliar application with insecticide spraying) avoids the introduction of more specimens to the affected palm tree or prevents the palm tree without affecting it, but it can rarely affect the pathogenic activity inside the palm tree.

Recommendations for “shower” type application at the base of the palms are as follows:

Imidacloprid-based insecticide (brands such as confidor, nuprid, etc.) liquid solution in concentrations of 1 ml per liter of water.

The application of imidacloprid can be alternated with microencapsulated diazinon 24%, Thiamethoxan 25% (in doses of 0.04%, Chlorpyrifos 48% (in doses of 0.2%)

It is also recommended, for dates with the presence of suckers, to take a shower over them since it is a source of infection.


It is made through holes with drills (previously sanitized). A hole is made in the trunk of the palm tree with a downward inclination and a length equivalent to the radius of the palm tree, (corresponding to the center of the trunk). Different perforations can be made at different heights in order to achieve greater absorption of the product (separation of 25-30 cm in vertical height) and between 0.5 and 1 meter from the crown of the palm tree.

The usual or recommended applications against the weevil consist of commercial brands of Imidacloprid 20% in concentrations of 1 ml per liter of water. Applicable amounts are based on covering the palm tree bore to overflow. Repetitions of the application are recommended every 45 days – 50 days

In order to avoid the onset of resistance to the product, imidacloprid 20% can be alternated with thiamethoxan 25% or abamectin 4.8%.

Possible treatment to carry out against the red weevil:


ALL YEARIMIDACLOPRID trunk injectionIMIDACLOPRID trunk injection
JUNE TO SEPTEMBERIMIDACLOPRID 20% every 45 daysIMIDACLOPRID 20% every 45 daysIMIDACLOPRID 20% (shower)
FROM OCTOBER TO MAYNEMATODOS (20 – 30 mill every 45 days)NEMATODOS (20 – 30 mill every 45 days)Nematodes (20-30 mill) every 45 days



This biological treatment against the weevil is based on a bioinsecticide (entomopathogenic nematode) which, once introduced inside the palm tree, comes into contact with the larva causing its death after 2 – 3 days.

The main problem it presents is the difficulty of penetration into the weevil pest, the price of the product and the sensitivity of the nematodes to conditions of temperature, dryness, etc.


This instrument consists of the placement of traps with attractants (pheromones such as kariomone) by which the weevil in adult stage is trapped. It is not a method of fighting the plague but a technique to evaluate the number of adults and their distinction between males and females.


Ecoring is a pioneering method developed by the Ecopalm company (Castellón), from the controlled emission of high frequency microwaves. Through a crane a ring is installed that surrounds the crown and base of the leaves (greater concentration of the pest).

These microwaves heat the water that is part of the weevil molecules (or other pathogenic organisms) destroying the organism in a matter of minutes.


The idea is to apply a concentrated broth to the palm tree’s eye that houses the Beauveria bassiana fungus   which attacks the weevil. This procedure is in the experimental phase although applications have been made in different areas of Spain. In optimal conditions it has a high percentage of efficiency (70% of larvae and around 100% of pupae and adults) and a power of action after 3 months of its application.

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