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.”