A serious threat to the Portuguese landscape
(Artículo en formato original original con fotos en http://www.aambiental.org/_en/PalmWeevil.htm )
In May 2008, Manuel Rodrigues of the Parks and Landscaping division in Silves, spent half a day showing the author the damage caused in that concelho by the “Gorgulho Vermelho” or Red Palm weevil. Thisarticle is the result of research undertaken since that experience. Almost nothing has been done to warn the public of a serious threat and how to tackle it, past and present official policies must change radically and much needs to be learnt about controlling the insect sustainably.
From Porto on the northern coast to the Algarve in the south, palm trees, and particularly theCanary Island Date, Phœnix canariensis, a sturdy, showy plant which once established could almost be forgotten about, constitute an important part of Portugal's landscape. (Figure 1)
Figure 1. Canary Island Dates in Silves.
With the arrival of the Red Palm Weevil, Rhynchophorus ferrugineus, in the Algarve less than two years ago, that has begun to change. In the first eight months of 2008alone, over 10,000 palm trees have been destroyed because of the weevil just in neighbouring Andalucía. This should warn us about what Portugal can expect. Since then the insect, which almost certainly entered the country in trees imported from Egypt or Spain early last year, has probably penetrated hundreds of palms in the Algarve and scores have already been killed. (Figure 2)
Figure 2. Theweevil's legacy in a garden in Figueira.
The problem is still new to Portugal but it is just another stage in a process which began in the 1980s when the beetle, native to Southeast Asia and Melanesia, started to spread west and north. Moreover, this new arrival in the Algarve is only a small part of a much larger picture the naturalist E.O. Wilson recognised long ago asa major challenge of our age - the invasion of exotic species. Portugal has certainly not been exempted and most of us would be astonished at how much foreign flora and fauna has become naturalised here. On its journey, the weevil has attacked coconut palms in India and ravaged date groves across the Gulf and parts of North Africa before spreading to much of the remaining Mediterranean.
Aswell as the common Agave and sugarcane, over 30 palm species including both of Europe’s two native palms are known victims. But the insect is particularly fond of date palms and, for reasons which remain a mystery, it is especially drawn to males of the Canary Island Date. According to a knowledgeable Spanish source, about 80% of trees lost to the weevil there are Canary males.
This is bad news for Portugal. Although it has no harvestable crop (apart from a little ‘honey’ tapping in its habitat), this handsome tree is the most visible and significant palm in the local landscape and it has been extensively planted, especially in the Algarve, in parks, hotels, villa developments and private gardens as a beckoning suggestion that the tropics aren’t so far away.Much of Portugal will look very different without its most common palms and there is every indication we will lose these exotics as well as true dates and Washingtonias in addition to other more unusual members of the family if serious, national and community-wide measures are not taken.
Brussels’ reaction has been too little, too late. The Commission adopted “emergency measures”to keep the insect out 14 years after it first arrived. By that time the weevil was well established across most of southern Europe. The response of different countries ranges from the exemplary - Israel overcame the weevil threat with a no-nonsense strategy in a few years - to deplorable - Spain identified Egyptian date palm imports as the source of the weevil, closed its borders but then...