The South American Palm Weevil (SAPW) is the latest in a string of pests to attack trees in Southern California and this one has huge destructive potential…
Females lay their eggs in the trunk of the palm below or in the base of fronds. The larvae then bore into the trunk and eat the living tissue of the tree. The weevil will eventually eat so much of the canopy that the palm will essentially starve to death. Incredibly, as few as 30 larvae can kill a mature coconut palm. Unfortunately for those of us in Southern California, the Canary Island date palms seems to be a particularly attractive host for the SAPW because its fleshy and numerous leaf bases make it an ideal source of food and shelter. If Canary Island date palms are unavailable, the weevil will attack other palm species common to our area like Mexican and California fan palms and other varieties of date palms.
Symptoms of a SAPW infestation include reduced new frond growth at the top of the crown and dieback in the top or middle of the crown. This dieback is in contrast to a healthy palm where the lower fronds brown and die as part of its natural lifecycle.
The South American Palm Weevil can also vector the parasite Bursaphelenchus cocophilus, which causes Red Ring Disease and is another cause of death in date palms. There is no cure for Red Ring Disease so prevention methods must focus on the weevil. Luckily for us, Red Ring Disease has not yet been found in California.
If you see dieback in the middle or top of the canopy of your palms (especially Canary Island date palms) contact your arborist immediately to assess whether the palm weevil is present and formulate a plan for treatment and containment. This pest has the potential to decimate palms in Southern California so control is critical not only for individual properties but for our region as a whole.
Shannon Miller, Director of Sales
Certified Arborist (WE-9539A)
Tee Risk Assessment Qualified (TRAQ)