Palm Tree Pests
Red Palm Weevil
California Palms can be attacked by a variety of weevils, prominent among them pbeing the Palmetto Weevil and the Red Palm Weevil. Weevils are a type of beetle that has mandibles at the end of a snoutlike projection of the head called rostrum. These modified mouthparts are used for feeding and to prepare holes in plant material in which eggs are laid. While adults feed outside the plant, the larvae (or "grubs"), which are legless, feed within the host plant.
The Palmetto Weevil, (Rhynchophorus cruentatus) is native to Florida and is the only species of palm weevil in the continental United States. The symptoms of a palmetto infestation vary. It can mainly be identified by a general and often irreversible decline of younger leaves. In palm species with upright leaves, such as the Canary Island date palm, the older leaves begin to droop during the early stages of infestation but quickly collapse thereafter.
As the infestation progresses, the larval feeding damage and associated rot is so severe that the integrity of the crown is compromised and the top of the palm falls over. This condition is termed "popped neck". If the palm is pulled apart at this stage, larvae, cocoons, and even adults may be found within the crown region.
The Red Palm Weevil (Rhynchophorus ferrugineus Olivier) is another variety of weevils that causes major damage to palm trees especially the Canary Island palms. It is difficult to detect the presence of a plague when they initially attack. Falling leaves and the cocoons found in the bores in leaves are initial signs of infestation. Early detection of weevil infestation is difficult, and treatment even in the early stages of infestation may be too late to save the tree.