If LBAM, Diaprepes, and Dufo were not enough, we now have a new pest that has the potential to change the face of southern California, the Red Palm Weevil. San Diego palm production is close enough to the infestation in Laguna Beach that we should be very concerned.

It wasn't all that long ago that I got a message in my email inbox that warned of the U.S. efforts to exclude all palm movement into the U.S. due to the Red Palm Weevil, so I wrote a short note about it in this newsletter (July 2010) and added it to the side bar in my newsletter. It didn't take long before the announcement that the Red Palm Weevil had been identified in Laguna Beach, the first record of this pest in the U.S. Now all of us need to know everything we can about this pest and be on the lookout for it wherever we go.

The destructive power of the red palm weevil is impressive (see: http://www.typicallyspanish.com/news/publish/article_25312.shtml and http://www.algarveresident.com/story.asp?ID=28841. This beetle is huge (1 1/2 inches) and even bigger than the Diaprepes Root Weevil. As a larva (grub) it can eat an awful lot of palm meristem turning the whole thing into mush. They appear to prefer the Canary Island Palm, adding to the myriad of pests of this palm in southern California, but they also attack many other palms and even agave. The host list includes Areca catechu, Arenga saccharifera, Arenga pinnata, Borassus sp., Calamus merrillii, Caryota cumingii, Caryota maxima, Cocos nucifera, Corypha utan (= C. gebanga, C. elata), Corypha umbraculifer, Elaeis guineensis, Livistona decipiens, Livistonachinensis, Livistonac saribus (= Livistona cochinchinensis), Livistonac subglobosa, Metroxylon sagu, Oneosperma horrida, Oneosperma tigillarium, Phoenix canariensis, Phoenix dactylifera, Phoenix sylvestris, Oreodoxa regia, Sabal umbraculifera, Trachycarpus fortunei and Washingtonia sp., plus sugar cane, Saccharum officinarum and century plant, Agave americana.

There is still a lot up in the air about how the regulators are going to handle the red palm weevil, but they are very serious about it (see the CDFA web site below). You can just imagine how the movement of palms from quarantine area will be nearly impossible. In addition, there is no real effective pesticide treatment at this time. Trapping and palm removal may be the eradication methods of choice. Experts from the Mediterranean (Many are on a Technical Working Group for this pest and are helping in the discussions and decisions.) have recommended removal of all palms within a mile of the infested site, and they are begging us not to make the same mistakes that they made in allowing populations to linger (Please read this note from one of the world's experts on this pest: http://www.palmtalk.org/forum/index.php?showtopic=25539&st=160). I don't think that will happen in southern California, but we will see. So far, only three infested palms are considered find sites in Laguna Beach.

There are some advantages to the current situation and some obvious disadvantages. First, the eventual quarantine will be somewhat limited because the finds are so close to the ocean. Half of the area in the initial zone is in the ocean. Second, the inhabited area of Laguna Beach is rather narrow with most of the land in the zone of interest is in natural reserve. Therefore, the majority of the palms of concern are in a relatively small area. In addition, nearly every palm has been surveyed by regulators (>18,000).

The greatest disadvantage at this point is that landscapers in the area claim to have seen the beetles there for more than a year. That's not good, especially since this beetle is a good flier and can disperse up to 3000feet or more than a mile.

If you are a palm producer, you should get on the Internet and inform yourself of the seriousness of the threat. Here are a few web sites that will get you started.

CDFA web site devoted to the Red Palm Weevil: http://www.cdfa.ca.gov/phpps/rpw/index.html

The site has a fact sheet with lots of photos, a new pest response guideline from the USDA, and lots of press releases.

This site has a postcard written in English and Spanish, and it has photos: www.rivcoag.org/opencms/system/.../RPW_Postcard_10-26-10_FINAL.pdf

The red palm weevil has caused so much damage in the Mediterranean area that the scientists working on the bug have created THE Red Palm Weevil Home page: http://www.redpalmweevil.com/ The headline on this page reads like this "This Web Site is the first Web in the world to introduce you to the most destructive and dangerous pest in the growing areas for coconut and date palms in Asia and other countries." As the headline suggests, this page outlines the movement of the bug into new countries and how destructive it has been.

And it has its own Wikipedia page: http://en.wikipedia.org/wiki/Rhynchophorus_ferrugineus

For more information about the life cycle and economic damage see: http://cisr.ucr.edu/red_palm_weevil.html

James A. Bethke, UC Cooperative Extension San Diego

Ph: 760 752-4715 email: jabethke@ucdavis.edu