The Coastal Gardener: Destructive beetle found in Laguna Beach

Imagine the Southern California skyline without the presence of majestic date palms and tall, slender Washingtonia fan palms.

That's what a few landscape professionals, palm enthusiasts and scientists are worried about, following the discovery last month of a destructive new pest in a Laguna Beach neighborhood.

For the first time ever, the red palm weevil, a beetle native of Southeast Asia, was discovered alive and well in the United States. The host was a Canary Island date palm in the Emerald Terrace neighborhood of north Laguna Beach.

Rhynchophorus ferrugineus is considered one of the most destructive palm pests in the world. Nick Nisson, Orange County's entomologist at the County Agricultural Commissioner's Office, identified the invader after a palm removal crew became curious about the unusual-looking insects.

Red palm weevils are relatively large and rusty red. Adult beetles lay about 200 eggs on the new growth at a palm's crown. But it is its larvae that cause most of the problems for palms. Impossible to see, the juvenile larvae feed on the soft fibers inside the palm, tunneling through the trunk for about a month, before they pupate, emerge as adult beetles and fly away in search of another palm. The larva's burrowing activity usually kills the host palm.

The beetle is a major pest of commercial coconut, date and oil palm plantations in much of the world. Originally from Asia, it spread to the Middle East in 1985 and reached the Mediterranean by the late 1980s. It was first recorded in Spain in 1994 and in France in 2006. Finally, the weevil made it to the Caribbean in January 2009.

Now it's in Laguna Beach.

Panic has already begun among palm enthusiasts. Members of The International Palm Society are sounding the bell. Comments and warning are coming in both locally and internationally about the potential destructiveness of this pest.

Tom in Laguna Beach writes:

"Only a mile from my house. Yikes!"

A palm enthusiast from San Diego is worried:

" … the palms that are hit by the weevil can't just be cut up and hauled away. The tree can't even be burned, it must be buried in a pit to prevent the approximately 300 weevils per tree from getting away so the growth pattern of the infestation does not grow logarithmically. The damage caused by a few larvae of the weevil is astonishing. Even one larva may cause considerable damage, and, sometimes the death of the palm."

Nigel from Brazil says: