Xylella fastidiosa, a bacterial disease, has been detected in 75 plant species in Portugal, including olives, citrus fruits, vine, peach, and cherry, and has spread rapidly in three municipalities in the Porto area. The Valencian association of farmers is concerned about the disease's impact on Spanish and European agriculture and urges administrations to take measures to control its spread. Reports also express concern about the vector that transmits Huanglangbing, already present in the Algarve area and approaching citrus groves in Huelva, and in Sicily, where it could destroy hundreds of thousands of hectares of oranges and lemons. Research is being done on resistant varieties, defensive substances, and agro-ecological systems to combat the disease.