Re: Red palm weevil alert from CDFA

Charles and the others who replied;
I don't post things here to be recognized for my contributions, or a pat on the back, although it may have sounded like that was what I was seeking by the tone of my email.  Simply put, if no one reacts to what I or others post, there is no interaction on this forum, and why bother communicating with the group?  Certainly no one is under any obligation to interact here, but the purpose is supposedly to inform and interact.

I've been following this topic on other forums for several weeks now, and referenced the information that is being discussed on the International Palm Society's forum, and is available to any one who is interested to read it.  The topic has been getting some press, certainly the Orange County papers have alerted their readers, and there was a very mediocre report in the LA Times a few days ago, which I personally thought didn't begin to address the issues nor the actions taken to date.  It is very disheartening to read about how political wrangling and fighting over jurisdiction allowed this pest to spread so rapidly in southern Europe, and the inability to force private property owners of infected palms to take action is as worrisome here as it is in Europe.  An infected palm continues to be a vector for hatching insects even after the growth point has died, and in a one year period of infection, there can be 1000's of new insects hatched.

It is a fact that fresh cuts on palms such as Phoenix canariensis do attract the red palm weevil, but it is often tree pruners cleaning up these palms that first discover the infestation.  It is also a know fact that the palms can be saved if the pest is caught in time, by removing the infected/infested foliage and treating with chemicals, whether that be topically or systemically, both can be effective, and large palms such as Phoenix canariensis may need follow up treatment every 6 months as a preventative.  Obviously that gets expensive over time, and isn't feasible for the thousands of palms throughout southern California.  The list of potential palms attractive to this insect is large, and it will have impacts on the agriculturally significant Date crop grown in the Imperial Valley desert.

I think it will soon be obvious that the invasion is already much more widely spread than we know at present, and if it is already spread into Mexico, I think it is hopeless to think we can stop it.

The search for adult insects is probably less effective a protective measure than becoming more familiar with early signs of attack on palms,  The IPS forum with this topic does a very good job of effectively communicating what to look for as early symptoms, and compares the damage done in contrast to other fungal/viral diseases that are also attacking Phoenix species in California.

The more people that are educated about this menace and know what to look for, the better chance we'll have to contain it.  There may not be much of a chance to use biological controls on this pest, although there have been uses of such controls in the tropics, especially India where it also attacks Coconut Palm plantations.

As to whether palms deserve to be protected as compared to our native Oaks, I personally think such comparisons are absurd.  Not just Phoenix species are at risk, but our one native palm, the Washingtonia filifera as well as W. robusta, Brahea species, Butias, Chamaerops, and Trachycarpus species, to name just a few of the more common species here in California.  At one time it was thought that Queen Palms, Syagrus species were immune, but it has been found that once all the Phoenix, their preferred host in a Mediterranean Climate are gone, they move on to other palm species.  And as I mentioned already, they can and do attack other plants such as Yuccas, Beschornerias and Agaves if there are no palms to be had.

At the very least, this will probably be a further blow to the nursery trade in California, with interstate shipments of palms and intrastate shipments as well either prohibited or made more complicated.  I don't think there is a real comparison with other relatively minor pests such as the Light Brown Apple Moth, which doesn't kill its host, and has most likely already been here for at least a decade. The moth is readily seen here in Berkeley/Oakland area and is a minor nuisance on my Leucadendrons which it loves to destroy the flowering tips.

At the very least, it has made me more aware of checking the health of mature palms in my clients' gardens, and has probably influenced me to start using fewer palms in my new design work.  As I must have a dozen species of palms in my own garden, I am also a bit worried personally as well.

I don't mean to sound overly alarming, but the progress of this pest in overwhelming European efforts doesn't bode well for success here, but maybe we can learn a thing or two from others' failures, and at least the apparent singular success up to the present in the Canary Islands.

From: Charles Dills <charlesdills@mac.com>
To: david feix <davidfeix@yahoo.com>
Cc: Plants Mediterraean <medit-plants@ucdavis.edu>
Sent: Tue, November 16, 2010 10:20:43 AM
Subject: Re: Red palm weevil alert from CDFA

Don't get concerned about the lack of response.

I believe most people on most forums are Lurkers.

They're there but silent and appreciate what you do.

So keep it up, and don't wait for a pat on the back! ---Chas---
===============================================

Karrie,
I had also posted about this to the Med Plants Group a couple of weeks ago, and got absolutely no responses from anyone on the forum.  It makes me think that people are either asleep at the wheel, or I am some sort of persona non grata with the group...  I find this discovery highly alarming myself, and suspect that it reflects just the tip of the iceberg; the pest is probably already widely spread in coastal southern California, maybe also in Mexico, and the amount of wild palms growing in difficult to access canyons and arroyos throughout southern California will make this extremely difficult to detect.  Not to mention that this pest can probably use Agaves, Yuccas and Beschornerias as alternate hosts, which appears to be the case from what I have been reading.

What makes it all seem so gloomy is that this pest raced across southern Europe in a period of 5 years from first detection in Spain on imported Phoenix dactylifera from Egypt, with an alarming spread and amazing incompetence to nip it in the bud when they had a chance.  It would appear the only EU territory with suitable conditions for its spread that has halted the pest is the Canary Islands.

Do you feel optimistic about stopping this pest here in the USA, or as I do?  Just curious.

Also, let's see how many people on this web forum comment on this...

Best,
David Feix

From: Karrie Reid <s*@ucdavis.edu>
To: medit-plants <m*@ucdavis.edu>
Sent: Tue, November 16, 2010 8:40:22 AM
Subject: Red palm weevil alert from CDFA

Here is the alert sent out by CDFA:

RED PALM WEEVIL, WORST KNOWN PEST OF PALM TREES,

DETECTED IN LAGUNA BEACH

Agricultural officials confirm first detection of palm tree pest in the United States

 

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 worldâs worst pest of palm trees.  An infestation typically results in the death of the tree.

 

âThis invasive pest is a threat not only to our nursery growers and date palm farmers,â said California Department of Food and Agriculture (CDFA) Secretary A.G. Kawamura.  âIt 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.â

 

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 treeâs 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.

Steve Lyle

Director of Public Affairs

California Department of Food & Agriculture

(916) 654-0462

-- 
Karrie Reid
Environmental
 Horticulture Advisor
UC Cooperative Extension, San Joaquin County 
2101 Earhart Ave., Ste 200
Stockton, CA 95206-3924

209-953-6109  
FAX: 209-953-6128




Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index