Trees that the South American palm weevil threatens include date palms, Canary Island date palms, coconut palms, African oil palms, sago palms and Washingtonia fan palms.

Villanueva says it is impossible to know how the weevils made their way into the Valley, but he speculates that a palm nursery near where the two weevils were discovered may be the source.

“This nursery imports palm fronds from South and Central America to use in floral arrangements, and the weevils may have come in on one of these fronds. It is also possible that with the large number of trucks carrying freight across the Texas/Mexico border every day the weevils were hitchhikers that made their way across the river,” he said.

The South American weevil is black and ranges in size from 1 to 2 inches in length. Sometimes the weevil will have a velvety appearance. Weevils smaller than 1½ inches are not considered a serious danger. Last year they found their way into Southern California, where the red weevil (Asian weevil) was also found.

Officials said it is difficult to detect weevil infestations because they live inside palms, but that infested palms will often suffer from notched new fronds or damage to the top of the crown.

Villanueva says the SAPW causes economic damage during the larval stage, when larvae feed on the growing tissues in the crown of the palm, often destroying the apical growth area and subsequently causing death of the palm. Populations of only 30 larvae have been reported as sufficient to cause the death of an adult coconut palm.

The red ring nematode, delivered into the palm by SAPW,releases a fungus which can kill palm trees within five months of inoculation.

While palm trees are the major target of the SAPW, the weevils will also feed on decaying oranges, which poses little threat to the Valley’s citrus industry, but Villanueva warns of greater concern as the weevil has also been known to infest sugarcane fields. If an infestation of SAPW were to occur, the Valley sugarcane industry could be at risk.

Officials warn nurseries and consumers to refrain from bringing palm trees, palm plants and fronds into the Valley and the state.

“This is the number one concern when it comes to introducing unwanted pests and diseases into an area,” Villanueva said.