The South American Palm Weevil (Rhynchophorus palmarum) is a destructive and invasive weevil known for attacking canary island date palms in their native areas of South America, Central America, Mexico and the Caribbean.
In December of 2010, there were reports of dying Canary Island palms in nearby Tijuana, Mexico. Examination found the palms to be infested and in 2011 the SAPW was first detected in San Diego County, just 5 miles north in neighboring San Ysidro, California. The SAPW was officially confirmed on May 9th by the USDA with several other detections taking course over the next few months spreading palm mortality throughout the border cities of San Diego.
The South American Palm Weevil…


As of January 2024, the South American Palm Weevil is active throughout most of San Diego County killing Palms and establishing new hosts along the way as far north as the 78 Highway. Monthly monitoring stations in Carlsbad and San Marcos are showing consistent adult palm weevil activity throughout the year.
The communities of Encinitas, Solana Beach, Del Mar, Rancho Sante Fe, Fairbanks and Carmel Valley are currently the most northern “hot zones” in the county of San Diego. Communities south of the “hot zone” where SAPW is now well established, are seeing many tragic palm deaths throughout these areas as well. Our maps provided below show the progressive spread of SAPW in San Diego County from 2020 to 2024 with the growing host list detailed.
SAPW Host List Continues to Grow
Currently the most susceptible and targeted hosts are the Canary Island Date Palms (Phoenix Canariensis). In our county, different host Palms just this year were confirmed as being attacked and killed by the SAPW. Other species that have confirmed SAPW infestations include:
Updated Host List: | |
---|---|
Bismark Palm | King Palm |
Butia Palm | Majesty Palm |
Canary Island Date Palm | Parajubaea |
Chilean Wine Palm | Queen Palm |
Dactylifera Date Palm | Reclinata Palm |
Guadalupe Fan Palm | Roebelenii/Pigmy Date Palm |
The weevil continues to travel north from its origination in south county. Current findings are being located as far north as Fallbrook/Bonsall and as far west as Ramona.

Understanding The Pest
SAPW has established its presence in our Southern California region further increasing the importance of knowledge and understanding of this pest to prevent further damage and death rates to our palms. These long-nosed weevils utilize their snouts as drills to enter a Palms meristem. Once a male weevil finds a suitable palm, it feeds on the meristem which emits a pheromone to attract a female counter part, the kairomones produced by wounds on the healthy or stressed palm create a foul-smelling odor further attracting adult SAPWs. The female then lays her eggs in the snout drilled tunnels providing a protective environment for the larvae to develop and feed on the tissue of the palm from the inside out.
Once big enough larvae will feed on the crown of the palm destroying its meristem tissue. The larvae will spin cocoons from the leftover palm fibers they cannot eat, causing the trees fronds to starve and die. This feeding by the larvae in the crown of the palm causes significant damage to the apical meristem and internal tissues which leads to its inability to produce new fronds resulting in the death of our iconic palms.
the drone image to the right shows a missing meristem view from top of the palm

Above images show a Canary Palm with early signs of decline, treated right away with a contact crown spraying and soil systemic. The canary palm was showing early signs of decline by the missing meristem in the left photo. After 4 treatments in 3 month intervals the picture on the right shows old damaged growth and new healthy growth coming in.

Signs & Symptoms
SAPW is often difficult to detect in early stages of infestation. The top or center leaves of the canopy will typically appear cut off or missing in an early symptom stage. The center of the canopy, which is often difficult to view from ground level can be seen with our drone technology.
Infested palms will often show a progressive lightening / wilting of the foliage. The infestation that occurs at the leaf bases can show signs of tunnels or grooving which are often filled with cocoons from larvae. The tunnels appear as holes where they travel from one leaf base to another. Larvae bore into the trunk and can completely destroy the internal tissue of a palm in as little as 6 weeks.
Once established in the center leaves, they will move into the apical meristem resulting in death/collapse of the center leaves and future growth. Fronds often droop or turn brown in color, because the structural damage is at the leaf base area, the leaves will often collapse or fall easily. The iconic normally upright palm fronds will then begin to tilt and collapse.
The rot damage caused by feeding can be so severe that trunk tissue is compromised, and the canopy can easily fall off. The destruction of internal tissues and apical meristem results in the death of the palm. Adult SAPW will then emerge and travel to other palms seeking their preferred habitat among the tightly packed palm leaf bases.
Treatment & Management
With our weather, the SAPW has shown the ability to be active year round. Our studies have shown that the SAPW activity is the highest from March through November, with peak activity in Summer months. In our 8+ years of managing the SAPW the following information has been gathered:
Preventative insecticidal applications are recommended to be made every 3 months throughout the year and have shown the best results in preventing future attacks. Insecticide treatments alone do not guarantee Palm survival.