A flutter of insect wings, a livelihood on the brink

29/05/2020

Long before it dies, the date palm hums. A faint internal droning, an intimation of agony. Tall and slender to the end, it carries itself well. You might not know it, but it is shutting down, gnawed away by the red palm weevil. Rynchophorus ferrugineus is on the march.

“From southeast Asia, the insect entered the Near East in the 1980s,” says Hassan al-Ayied. An entomology professor at King Abdulaziz City for Science and Technology in Riyadh, al-Ayied has been sharing with FAO 20 years-worth of observation of the red palm weevil. “It landed in the east of Saudi Arabia, inside imported ornamental palms. It could have been stopped in its tracks then. But it wasn’t.”

Every year or so, the pest sticks a pin – or rather, a curved hairy snout – in a new country or region. From the Near East, it spread to parts of Africa, the Caucasus and the Mediterranean. By 2019, it had reached as far north as the Balkans.

Highly invasive, the pest is also gregarious. Multiple generations will colonize a single tree: larvae, pupae, adults. The females lay their eggs in crevices, 300 at a time. From the eggs, the larvae emerge: they feed by burrowing down, leaving a trail of “frass,” a mess of faecal ooze and chewed-up fibre. Away they tunnel, their destructive whirr inaudible except with costly special gear.

Occasionally, frass spillage will alert the growers in time to allow partial rescue of the palm. Often though, the tree dies undiagnosed, its vascular system shot.

Around 2010, the Caribbean island of Aruba was busy developing its picturesque coast. “They wanted vast numbers of ornamental palms,” al-Ayied recalls, “so they sourced them cheaply from North Africa. The trees came contaminated.” Aruba’s warm, humid conditions were ideal for propagation; from there, the pest jumped to nearby Curaçao.

It was long thought that the key to the weevil’s diffusion was its ability to fly long distances. That theory has lately been debunked: the longest documented stretch it can fly without stopping is 69 metres. “If the red palm weevil now covers large parts of the globe,” al-Ayied says, “it’s because of lapses in the international palm trade.”

The Near East, with its vast date-growing sector, remains the weevil’s juiciest conquest. FAO estimates the bug has burned through half a billion US dollars’ worth of date palms and left millions of farmers fearing ruin.

Anwar Haddad leads the Jordan Dates Association. In the northern Jordan Valley, the plots are often tiny, the trees old and the varieties unfashionable. Growers there struggle at the best of times; Haddad reckons 80 percent of their farms are infested. But even in the Valley’s central and southern parts, where date-farming is investment-driven and export-oriented, he estimates infestation rates at 20 percent and rising.

“It’s what we fear most, our main concern,” Haddad says. “Until recently, growers would hide weevil infestations: they were worried about the effect on market confidence and the price of seedlings. We’ve worked hard to shift attitudes – they’re now openly seeking help.”

Top-end varieties – the dusky Saudi Ajwa, or the more widespread amber Medjool – are highly prized commodities. But that is not all. In the cultures of Arabia, North Africa and the Levant, the date glows with a mystique that transcends sheer economics. A by-word for nutritious self-sufficiency, the fruit has traversed the ages as decorative motif, the stuff of Holy Book parables, the Bedouin’s superfood. FAO itself has championed the date as an “extraordinary fruit”.

“You could just about live off dates and water, and until not so long ago many did,” says Maged Elkahky, an Egyptian agronomist and FAO’s go-to expert in the management of the red palm weevil. “I grew up a city boy with a far more varied diet, but even so, dates remain part of our daily universe.”

In late 2019, UNESCO declared the date palm an intangible cultural heritage. As it cuts into profits for big farmers and threatens to wipe out small ones, the weevil also undermines a regional identity marker for all.

Elkahky says eradicating the pest is technically possible – Mauritania, on the westernmost edges of the Sahara, is now weevil-free, and so is the United States, after an isolated breakout was extinguished in Laguna Beach, California. “These successes apart, the trouble is that weevil control has largely been handled from the commercial side, with offers of silver-bullet cures that haven’t been necessarily proven to work.”

Elkahky’s preferred approach is more inclusive and public policy-driven, relying on the accretion of institutional and field steps. He and his team have been pooling knowledge, laying down guidelines and coordinating weevil-busting efforts across infested regions. They are piloting an app, SusaHamra, named after the Arabic for the insect: once rolled out, it will analyse field data to throw light on what is being done well and where. A global database of date growers, exporters and importers is in the works. FAO is meanwhile helping countries draft legislation and rev up their phytosanitary capacity.

Down at farm level, enough of a body of wisdom has evolved to make a difference. Because the weevil loves a wounded tree, cuts made to the trunk when offshoots are collected should be immediately treated and sealed up. Tree inspections should occur at least every six weeks. There should be constant control of plant nutrition and monitoring of humidity conditions. In Jordan, the Dates Association is setting up a team of agricultural engineers to inspect farms twice a month and train labourers, particularly in the beleaguered north.

Where the palms are found to be infested, they should be carefully disposed of. The area must be quarantined without delay, and the trade in offshoots stopped. Professor al-Ayied says eventual quarantine measures in Saudi Arabia have spared parts of the kingdom, even as the bug spread beyond its national borders.

Building a food-secure world also entails eradicating the red palm weevil. FAO’s experience suggests this will be a many-pronged affair: the timeline is most likely generational. But it is starting to look, magnitude of the job aside, like a conceivable reality.

Related links

Learn more

• Website: Food chain crisis: Red Palm Weevil
• Publication: Red Palm Weevil: Guidelines on management practices
• Story: 5 facts about dates that make them an important food of our future