Red palm weevil: the signs that mean you still have time

A mature Canary Island date palm takes decades to grow and about four months to lose. The red palm weevil does its damage entirely inside the trunk and crown, so the tree looks healthy long after the outcome has been decided.

Detection is the whole game.

The signs, in the order they appear

Weeks 1–6: nothing visible from the ground. Eggs are laid in a wound, a pruning cut or a frond base. Larvae begin tunnelling inward. There is no external symptom at all.

Weeks 6–12: the first real signals. These are the ones worth learning:

• Chewed fibrous material, like damp coconut husk, at the frond bases
• A reddish-brown ooze from the crown, sometimes with a faint fermenting smell
• Fist-sized fibrous cocoons on the ground beneath the palm
• Audible chewing from inside the trunk on a still evening. Genuinely, you can hear it

Weeks 12+ — visible decline. A single frond in the centre of the crown yellows and droops. Then the crown becomes visibly asymmetric, one side dying back faster than the other.

The end. The crown collapses, often in one piece, often without warning. This is a safety hazard as much as a horticultural loss.

The window

Treatment applied during the first two stages saves the great majority of palms. Treatment applied once the crown is asymmetric saves some. Once the crown has collapsed, the growing point is destroyed and no treatment brings a palm back.

That is why inspection beats reaction with this pest, and why the inspection has to be monthly through the season, not annually.

What makes it worse

Two avoidable things account for most infestations we see:

1. Pruning between March and November. A fresh cut releases volatiles that attract egg-laying adults from a considerable distance. Prune in winter, and seal every cut immediately.
2. Moving untreated palm material. Bringing in a new palm, or moving green waste from an infested tree, moves the pest with it.

If you find it

Do not cut into the crown to investigate. That opens more egg-laying sites and can accelerate the collapse.

Photograph what you found and get the palm inspected. Treatment is crown drenching plus trunk injection with authorised systemic products, supported by pheromone trapping to reduce local adult pressure. Palms beyond recovery have to be felled and disposed of correctly, because an untreated infested trunk left on site will seed every palm around it.