Red palm weevil

What you are looking at

A palm whose central, youngest fronds start wilting, yellowing or drooping while the older outer fronds still look completely normal, an early and easily missed sign that something is wrong deep inside the trunk. Left untreated, an infested palm’s entire crown can collapse suddenly with little further warning, because the weevil’s grubs have hollowed out the fibrous tissue that holds the crown up from within.

Cut into an affected trunk and the damage becomes obvious. A hollow, fibrous cavity sits inside, sometimes packed with fat, legless, cream-coloured grubs up to 5 cm long with a dark brown head. From outside, holes in the trunk sometimes ooze a gummy, fermented-smelling liquid, occasionally with chewed fibrous frass pushed out alongside it. The adult is a large reddish-brown weevil, 2 to 5 cm long, with a long curved snout, occasionally seen flying at dusk but rarely noticed before the damage it has already caused becomes visible.

From South Asian coconuts to Mediterranean date palms

Native to the Indian subcontinent and Southeast Asia, this weevil damaged coconut palms there for well over a century before international trade in ornamental palms carried it to the Middle East in the 1980s. From there it spread across the Arabian Peninsula, North Africa and the Mediterranean basin, where it is now the dominant threat facing both commercial date palms and the ornamental Canary Island date palms planted along so much of southern Europe’s coastline. It is currently present in roughly 49 countries.

Isolated detections have occurred in parts of the southern United States and the Caribbean, but a self-sustaining population has not established across North America, and any find there is treated with the same urgency as a first arrival anywhere else. Australia and New Zealand have never had it and both treat a suspected sighting as an immediate biosecurity matter.

What to do about it

Buy palms only from certified, inspected nurseries, since infested ornamental stock is the main way this weevil crosses into new regions.

Avoid unnecessary pruning wounds and mechanical damage to the crown, and seal any cuts promptly, since adults are drawn to the scent of fresh wounds.

Where the weevil is present, monitor high-value palms with pheromone traps and treat early-stage infestations with entomopathogenic nematodes or fungi applied by a professional; a heavily infested palm is rarely saveable once symptoms are visible from outside, and preventive insecticide injection is a last resort worth discussing with a professional only for an exceptionally valuable specimen.

Report a suspected infestation immediately rather than waiting to confirm it personally, given how much damage happens hidden inside the trunk before any external sign appears.

Stay clear of a palm suspected of heavy infestation; a collapsing crown is a genuine physical hazard.

What it gets mistaken for

Honey fungus kills a broad range of trees and shrubs gradually, with white fungal sheets under the bark near the base and toadstools appearing in autumn, quite different from the fibrous hollowed trunk and gummy oozing holes this weevil leaves specifically in a palm.