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  • Weevil detector could protect palm trees

[CAIRO] A machine that detects the red palm weevil, a pest that devastates palm trees across the Middle East and North Africa, could help farmers protect their crops.

The tiny red insects burrow into the trunks of palm trees and devour them from within, so infestations — known as "date palm AIDS" — are usually unnoticed until the weevils have hollowed out the trunks. The trees then collapse beneath their own weight or are blown over by the wind.

"The red palm weevil is the worst known palm tree pest in the world," Ali El-Banna, president of the palm tree laboratory at Egypt's Agricultural Research Centre, told SciDev.Net. It has affected a quarter of Egypt's 12 million palm trees, he added.

"Farmers used to depend on the physiological symptoms that appear in the very late stages. Now, with the machine, we can rescue the tree before it's too late," he said.

The machine, designed by Egypt's Defence Ministry, works "like a metal detector", according to its inventor, Ahmed Amin. It is programmed with the molecular signature of a weevil's DNA and identifies a match when it is pointed to an infected area of trunk, by emitting electronic shock waves. By detecting which part is infected, the machine helps to minimise the amount of pesticide applied.

The machine won second prize at the Khalifa International Date Palm Award in the 'best new technique' category earlier this year (15 March). It has been approved by the Egyptian government —although no decision on funding has yet been taken — and the Agriculture Ministry will assess this month how many machines are needed to start fighting the disease in Egypt and nearby countries.

El-Banna hopes the machine will be marketed abroad, and added: "We have made a list of other agricultural diseases in order to study the ability of using the machine [to detect them]".

Gamal Hegazy, a weevil biological control expert at the Arab Organization for Agricultural Development, was less optimistic about the machine. "After detecting the weevil with this machine, we can kill the insects — but their bodies will remain inside the tree trunk. Therefore the machine will detect the dead insects as well."

But he said it was a "vital first step" towards a machine that can both detect and kill the pest. There is another promising experimental machine that combines both these functions, he said, but it needs more work.