Sometimes the threats that I warn you about do not come to fruition such as my warning of the potential Erythrina gall wasp destruction of coral trees that I have seen in Hawaii http://hawaii.gov/hdoa/pi/ppc/2006-annual-report/erythrina-gall-wasp. However, that does not mean that we need to be less vigilant. There is a new threat that the USDA APHIS is taking seriously, and back in January, they issued a Federal Order: http://www.aphis.usda.gov/import_export/plants/plant_imports/federal_order/index.shtml#palmpests
www.doacs.state.fl.us/pi/pest_alerts/pdf/giantpalmweevils.pdf
 
There are two weevil species of interest and one of them vectors a phytopathogenic nematode. A description of the two beetles is below.
 
The red palm weevil Rhynchophorus ferrugineus (Olivier) infested palm trees in Egypt beginning in 1992 and the infestation was so extensive that it was responsible for what was considered the greatest loss of palm trees ever encountered in Egypt (Malumphy, C., and H. Moran. 2007. Red palm weevil Rhynchophorus ferrugineus. Central Science Laboratory Plant Pest Notice 5). The insect larvae are described as voracious and often penetrate the crown and most of the trunk of the palm. The tunneling causes weakened trunks, and the trees will fall or if there is enough damage to the crown, they are decapitated. To see photos and movies etc., about the red palm weevil, see this web site: http://redpalmweevil.com/RPWReport/Egypt.htm
Females weevils live for an average of 170-194 days depending on the host, and can lay approximately 125-184 eggs in lifetime depending on host.
Its range has expanded into the Middle East, North Africa, the Mediterranean, and now the Caribbean.
Just as a reminder, the Diaprepes Root Weevil comes from the Caribbean and got to us through Florida.
To see a pest note and more information from Florida, visit the following web site: www.doacs.state.fl.us/pi/pest_alerts/pdf/giantpalmweevils.pdf
 
One of the Giant Palm Weevils Rhynchophorus palmarum L. is just as serious a pest of palms as the red palm weevil, but this weevil originates in the tropics of the Western Hemisphere. The giant palm weevil affects both palm plantations and ornamental palms throughout Central and South America and has the potential to extend its range into palm-growing areas of the U.S., hence the reason for adding it to the Federal order.
An adult female weevil can live an average of 147.7 days and lay an average of 245 eggs in her lifetime, to a maximum of about 700 eggs.
The most serious damage is observed on the following species of palms: Cocos nucifera, Elaeis guineensis, Euterpe edulis, Metroxylon sagu, Phoenix canariensis, Phoenix dactylifera, Saccharum officinarum. The larvae feed in the crown of the palm, often destroying the apical growth area eventually killing the palm.
For more information see the following web sites: http://http://www.eppo.org/QUARANTINE/insects/Rhynchophorus_palmarum/DS_Rhynchophorus_palmarum.pdf
Unfortunately, this pest is also the main vector of another palm pest, Bursaphelenchus cocophilus (Red Ring Nematode). Giant palm weevil larvae ingest the nematodes while feeding on a nematode-infested palm then transmit the nematode to other palms as they disperse and lay eggs. The distribution of the red ring nematode follows its vector very closely, and the affected countries report palm crop loss of 10-15% or higher due to this nematode.
For more information, see the following web site:
http://edis.ifas.ufl.edu/in392
If you see any of these large weevils, please contact my office or the ag commissioner's office immediately. I would also caution you to be careful when you purchase stock from out of state, to make sure they are palm weevil free. If this pest gets into Florida or California, we will see the landscape here change significantly.
Years ago, the extension specialist at UC Riverside was caring for large palm tree slices (8-12 inches think) that were infested with the Palm Borer, another native, very large beetle that tunnels palm trunks. I remember seeing beetles emerging from those palm slices for long after they were brought to the facility. The palm trees that the slices came from were in the Palm Springs/Indio area. In that area, the numbers were so heavy that they were sweeping the beetles up each morning in the streets. We may face the same fate, if we are not careful.

James A. Bethke
UC Cooperative Extension San Diego
760-752-4715

presentations, irrigation supplementary topic

tour of local greenhouses