SACRAMENTO, October 18, 2010 - Agricultural officials have confirmed the detection of a red palm weevil in the Laguna Beach area of Orange County - the first-ever detection of the pest in the United States. The weevil is considered to be the world’s worst pest of palm trees. An infestation typically results in the death of the tree.
“This invasive pest is a threat not only to our nursery growers and date palm farmers,” said California Department of Food and Agriculture (CDFA) Secretary A.G. Kawamura. “It also endangers all of the decorative palms that are so common in our landscape and so much a part of the classic California backdrop. I would like to express my gratitude to the landscape contractor who originally reported this pest. He is a Good Samaritan who did the right thing when he took the time to notify local agricultural authorities, and he has given us a very valuable head-start in our efforts.”
In response to the original contact by the landscaper, state and local agricultural officials, working in partnership with the USDA, began an extensive, door-to-door survey in the neighborhood and are setting about 250 traps to determine if an infestation exists. Protocols for this pest call for an initial survey covering a 1.5 square mile radius around the detection property, resulting in a trapping array covering nine square miles.
The red palm weevil, scientific name Rhynchophorus ferrugineus, is a major pest of palm trees, many of which are highly valued as landscaping plants, generating approximately $70 million in nursery plant sales in California annually. Palm trees are also used for producing crops and marketable agricultural commodities including coconuts, dates and oils. In California, date palm growers harvest an annual crop worth approximately $30 million. The vast majority of these farms are in the Coachella Valley region.
The red palm weevil is native to Southeast Asia and has spread throughout the Arabian Gulf. It is found in parts of Asia, Africa, the Middle East, Europe and Oceania. Prior to the detection in Orange County, the closest confirmed infestation to the United States was in the Dutch Antilles in 2009, the first report of the pest in the western hemisphere. It was also confirmed in Aruba in 2009.
Female red palm weevils bore into a palm tree to form a hole into which they lay eggs. Each female may lay an average of 250 eggs, which take about three days to hatch. Larvae emerge and tunnel toward the interior of the tree, inhibiting the tree’s ability to transport water and nutrients upward to the crown. After about two months of feeding, larvae pupate inside the tree for an average of three weeks before the reddish-brown adults emerge. Adults live for two to three months, during which time they feed on palms, mate multiple times and lay eggs.
Adult weevils are considered strong fliers, venturing more than a half-mile in search of host trees. With repeated flights over three to five days, weevils are reportedly capable of traveling nearly four-and-a-half miles from their hatch site. They are attracted to dying or damaged palms, but can also attack undamaged host trees. Symptoms of the weevil and the larval entry holes are often difficult to detect because the entry sites can be covered with offshoots and tree fibers. Careful inspection of infested palms may show holes in the crown or trunk, possibly along with oozing brown liquid and chewed fibers. In heavily infested trees, fallen pupal cases and dead adult weevils may be found around the base of the tree.
Residents are encouraged to report suspect infestations by calling the CDFA Pest Hotline at 1-800-491-1899.