This is the No. 1 enemy of palm holders! It takes between 2 and 5 years for a palm weevil to overcome a tree.
Don't panic, there are prevention solutions and ways to eradicate this pest.
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What is the red palm weevil?
Rhynchophorus ferrugineus its Latin name is a large beetle measuring 3cm long. They are recognized by their orange color spotted with black. Their stiff wings are covered with black streaks.
The chilly insect deploys them only at temperatures above 25 ° C. It then flies up to 7km! The larvae have a plump, creamy orange body and an encapsulated tip.
A weevil lives about 3 months and females lay between 100 and 300 eggs during this time. To reproduce, males emit a pheromone that is increased tenfold with the smell of palm trees, which is why these pests make their home there. The females lay eggs in the heart of the tree stipe, a few days later the eggs hatch. Breeding occurs when it is above 15 ° C, with a peak noted in spring and fall. The larva will then begin to feed by digging galleries which will weaken the palm tree. She will use the fibers of the latter to form a cocoon and begin pupation.
Symptoms and damage
By digging galleries, the larvae cause rots. You can recognize an affected palm tree because its palms turn brown, lower, or even fall. The fins also have small notches and the stems are found with clumps of fibers. Two species are more affected than the others: the date palm (Phoenix dactylifera) and the canary palm (Phoenix canariensis).
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The south of France is the hardest hit, for two reasons. On the one hand, the Mediterranean rim is an ideal area for growing palm trees. On the other hand, the red weevil cannot tolerate temperatures below -5 ° C. They cannot therefore be used in regions subject to frost.
Prevention measures against the palm weevil
- Treat your palm wounds immediately witha mastic or a healing paste. Indeed, an injury is an ideal gateway to laying eggs.
- Perform fin pruning in winter, when temperatures are low, weevils do not fly and reproduce.
- Preferably plant species resistant to the weevil, Syagrus and Washingtonia palms would be more robust against this pest.
A struggle governed by law
It is difficult to detect the presence of the pest because it avoids the sun. When the latter is out, it hides in the fibers of the tree, and the same goes when it is too cold. Very often, when we see it, it is already too late ... This is why a national decree was drawn up in 2010 and is regularly amended. The fight is thus compulsory and regulated for any palm owner, whether it is a professional or an individual. This decree requires the declaration of suspected presence of the weevil to the town hall.
The community is then asked to confirm this presence and an action perimeter of around one hundred meters. All the palm trees in this area will then be monitored and even treated so that the pest does not spread. You must then use licensed professionals, you are not allowed to provide the treatment yourself. The trees will then be treated with fungicides and insecticides, before being sanitized. If the terminal bud is attacked, the palm will need to be felled. Following an intervention, the tree will be treated regularly.