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Slow death in Arabia:  Date palms face extinction

Middle East London Feb 1998.

 

Abstract: 

All 50 million of Arabia's date palms are under threat of extinction from a virulent pest imported from Pakistan.  Million of Red Palm Weevils threaten the multi-million dollar date industry and the survival of a cultural icon.  

All 50 million of Arabia's treasured date palms are under threat of extinction from a virulent pest imported from Pakistan. With relentless efficiency, millions of Red Palm Weevils are now infesting the region's palm groves. At stake is the multi-million dollar date industry and the survival of a cultural icon that dates back 5,000 years. Frank Gardner reports on how the Gulf governments are fighting back with some unusual weapons. From his small, spartan office in the UAF's Ministry of Agriculture, Dr. Salim Hanounik exudes a curious air of calm, considering that he and his colleagues have been tasked with saving the entire population of Arabia's date palms. "The problem," he says, drawing heavily on his cigarette, "is extremely serious. If we do not act now, the date palm industry here is finished."   Syrian-born Dr. Hanounik is the Regional Co-ordinator of the Biological Control of Red Palm Weevils in GCC countries, a weighty title for a weighty task. The problem comes in the form of a five-centimetre-long insect - the Red Palm Weevil. Believed to have crossed into Arabia in ornamental plants from Pakistan in 1985, the weevils have now infested over 10,000 farms across Arabia. As their larvae hatch from weevil eggs laid on the tree, they bore into the trunk then create a labyrinth of tunnels which eventually kills the tree. According to Dr. Hanounik, each infected tree produces enough weevils to infect at least seven healthy new trees a year. Some basic arithmetic produces a sobering statistic. Conservative estimates put the number of infected trees in the region at 300,000. Left unchecked, such an exponential infection rate could, theoretically, blight the last remaining healthy date palm in just over two years' time. The idea of an Arabia without date palms is hard to imagine. For thousands of years this hardy plant has provided food, shade and shelter for the region's Bedu and town-dwellers alike. Since it is also mentioned in the holy Koran, it retains an almost sacred significance for Arabia's 25 million inhabitants, appearing in Qatar's and Saudi Arabia's national symbols and on the UAE's currency. It is also big business. According to official estimates, in 1996 Saudi Arabia produced 570,000 tonnes of dates worth US$203 million, with exports valued at over US$30m. So what exactly are the Gulf states doing to confront this winged plague? "To face this problem," says Dr. Hanounik, "efforts initially focused on the use of traditional control methods like insecticides, quarantine regulations and tree-cleansing. But the cryptic feeding habits of the insect inside the tree trunks made it hard for the insect to be got at with chemicals."

There was also the environmental factor. Throughout the Gulf there is a move away from toxic pesticides and in the UAE - one of the two countries worst affected alongside Saudi Arabia - the government has cracked down on harmful chemicals, recently adding five more organo-phosphates to its list of banned pesticides.  In the latter half of 1997 the six governments of the GCC launched a five-year project to tackle the Red Palm Weevils using naturally occurring organisms that are not harmful to man. The Director General of the Arab Organisation for Agricultural Development (AOAD), Dr. Yahya Bakour, lobbied hard for financial backing and got it. The Islamic Development Bank (IDB) has come up with US$1.7 million of funding, while the Romebased International Fund for Agricultural Development (IFAD) has contributed a further US$lm. But faced with the enormous cost of setting up laboratories, offices and experimental sites as well as putting hundreds of researchers into the field, the project has had to rely heavily on contributions by GCC ministries of agriculture, in particular those of the UAE and Saudi Arabia. Now that the structure is in place, the team are concentrating their energies on a bizarre but effective biological weapon: the entomopathogenic (literally`insect-sickening') nematode. Dr. Hanounik, for whom the biological control of pests has been a lifelong work, has pioneered a method whereby live tropical nematode worms are injected into the trunks of infected palm trees. Once inside, they remote-sense the weevils, bore into them and then release a deadly bacterium which kills them through blood poisoning within 72 hours. Despite their gruesome behaviour, Dr. Hanounik says the nematodes cause no harm to the environment, people or plants, yet they can control more than 200 known pests. As well as the nematodes, he is focusing his energies on the use of naturally occurring fungi, bacteria and viruses to suppress the Red Palm Weevils. Although the nematodes are imported from abroad, Dr. Hanounik is keen to stress that such `beneficial organisms' are extracted and used locally in the Gulf region. The team's tactics are more intricate still. In order to concentrate the destructive weevils in one place and kill them, the project is using two naturally occurring substances known as aggregation pheromones and kairomones. "These pheromones," says Dr. Hanounik, "are chemical compounds produced in minute quantities by male weevils which causes them to gather in a hotspot. Kairomones are compounds emanating in tiny quantities from the fresh scars of trees that have been recently pruned. We use these two compounds to lure, trap and kill the weevils in mass quantities and it's the first time they've been successfully tested against the Red Palm Weevil." But first the team has to locate the infected palm groves. By using satellite remote sensing and imaging technology they aim to build up a comprehensive picture of the weevils' geographical distribution across Arabia. Once a weevil infestation is located from the air through colour changes, the priority is to eradicate them and prevent them from spreading to healthy plantations. Despite the scientific nature of the project, there is an element of intermediate technology about it. The aim of the first phase, which will last until the year 2000, is to develop and implement an effective technology for combatting the weevils. After that, the last two years will be devoted to transferring this technology on a large scale to Arabia's benighted date palm farmers. One of our main objectives," says Dr Hanounik, "is to establish national teams in GCC countries that can carry on the work after the project is completed. To this end we are training field workers and young Gulf scientists in various methods of biological control of pests." As well as setting up laboratories in Qatif, Saudi Arabia, and Ras Al Khaimah, UAE, the project aims to establish a regional research network amongst GCC countries that is closely linked with international research centres around the world. Red Palm Weevils are by no means limited to Arabia; they already have a foothold in the Indian subcontinent, Southeast Asia and other tropical palm-growing regions.  For the past 12 years it seems the Red Palm Weevils have had an almost free rein in Arabia. Largely unaffected by chemicals and often invisible to farmers, they have silently wreaked their damage on the region's most famous plant. Now, as their destructive power is set to magnify, they may finally have met their match. As the Arab Organisation for Agricultural Development's project takes off, the region's scientists will be pitting nature against nature. With millions of weevils still at large, the team members are keenly aware that time is not on their side. Dr. Hanounik is taking no holidays. 


 

Setting a worm to catch a weevil


The Economist; London; Oct 18, 1997

 Abstract:
Arabia's Gulf states are under attack from a powerful enemy: the red palm weevil (Rhynchophorus ferrugineus). The armor plated insect has had a devastating effect on Arabia's 25m treasured date palms. The answer lies in a obscure and virulent tropical nematode worm.

ARABIA'S Gulf states are under attack from a powerful enemy. Neither Iranian nor Iraqi, this ruthless foe measures just five centimetres (two inches) long and goes by the name of Rhynchophorusferrugineus: the red palm weevil, for short. Since it arrived from Pakistan in the 1980s, the armour-plated insect has had a devastating effect on Arabia's 25m treasured date palms. More than 10,000 farms on the peninsula are now infested. Saudi Arabia's date industry alone is worth $200m a year. There are even fears that dates-Arabia's 5,000-year-old "fruit of life"-could be wiped out. The prospect of an Arabia without palm trees-one ofthe few plants to thrive everywhere in its unforgiving climatehas so alarmed the Gulf's governments that they have launched a five-year international programme to fight the plague. Financed by the Jeddah-based Islamic Development Bank, the $2.7m project is hoping to attack the weevils with a natural parasite, since man-made pesticides have so far failed.

 The weevils wreak their destruction by laying eggs in "wounded" palm trees, that is, trees that have been recently pruned leaving open scars.When the wevils' larvae hatch, they bore a network of tunnels inside the trunk. Immune from outside attack, they spread through the tree, weakening it until it dies. Like any other self-respecting parasite, the weevils then move on to find another host. The answer, it is thought, lies in an obscure and virulent tropical nematode worm. Like minuscule tunnel-rats, the nematodes will be injected into infected palm trunks where they will seek out the weevils and attack them at all stages of their life-cycle. Once inside a weevil's body, the worm releases a lethal bacterium that causes blood poisoning and death within three days. That, at least, is the theory. As yet, the strategy has been tested only in the laboratory, not yet on the tree. In the meantime, the march of the weevil continues unabated. An immediate task is to isolate and quarantine the farms already infected. The anti-weevil project intends to use remote satellite imaging to detect colour changes and thus identify which palm groves are infected. But with Arabia's population, now 25m, growing fast, there is pressure to increase the number of cultivated areas that have greened the region since the oil boom of the 1970s. Like the plot from a Hollywood disaster film, new farmers are unknowingly starting to recultivate old abandoned farms that are crawling with the destructive weevils. Reproduced with permission of the copyright owner. Further reproduction or distribution is prohibited without permission.