Signs of an infestation by the Red Palm Weevil and methods of combating
Green leaves hanging down
Red Palm Weevil:
...and its larvae:
The Red Palm Weevil
The Rhynchophorus ferrugineus (Red Palm Weevil) is an about 3.5cm long, reddish-brown beetle (Coleoptera) from the family of the weevils (Curculionidae), originally coming from Southeast Asia. He was deported in 1994 to Spain and the Canary Islands by the export of plants and can be found now in other Mediterranean countries, as in France or Italy for example. The Red Palm Weevil has various and numerous host plants. Here in Portugal, it is primarily palms and among these especially the Phoenix canariensis, which are preferred infested by him. The Phoenix canariensis is a feather palm that can reach a height of up to 15m and its original home are the Canary Islands. The infestation of other palm species such as the Phoenix dactylifera or the Washingtona robusta has been reported rarely in Portugal.
The Red Palm Weevil can cause considerable damage to an infested palm tree. Usually the female drills a whole for each egg in the crown area of the host plant. Even wounds in the root area are a preferred storage location for those egg. Rarely is the attack via the root system (eg in the Phoenix dactylifera), in which the eggs are deposited nest-like. After hatching, the larvae, which are in full-blown state about 5cm long and 2cm wide, drill inside the palm and eat there, starting from the top drilling meter long passages in the trunk of their host plant. The entire crown area is decomposed in succession through the feeding activity. As an outward sign seemingly healthy palm fronds break off from the middle of the crown region.
Combat against the Red Palm Weevil
Because of the “importation” of the Rhynchophorus ferrugineus from Asia to Europe, the weevil does not encounter any of his natural enemies (although there have been attempts to settle those antagonists as a countermeasure for his unhindered spread in the Algarve). As an appropriate and financially reasonable palm protection the use of systemic insecticides for plant protection is advised in the Algarve at this moment. Curative treatments or preventive measures in order to combat or prevent an infestation of the Red Palm Weevil can be carried out. Official institutions in Portugal call for a fight against the Palm Weevil as well.
Some carefully treated and finally saved palm trees:
Rhynchophorus ferrugineus: Signs of an infestation
Treatment against the red palm weevil
New leaves start growing
Finally saved palm tree
More palm trees...
Some saved palm trees: