Citrus Leprosis: Centennial of an Unusual Mite–Virus Pathosystem

Citrus leprosis is one of the most economically important diseases of the Brazilian citrus industry. It is characterized by the presence of local lesions on fruits, leaves, and twigs or branches, which directly reduce production and lifespan of citrus plants. The etiologic agent is the Citrus leprosis virus C (CiLV-C) transmitted by tenuipalpid mites of the genus Brevipalpus. Every year, control of the vector mite costs Brazilian growers around US80 million. This disease was originally described from the State of Florida in the United States over a hundred years ago, and was found later in Paraguay, Uruguay, Argentina, and Brazil, where it is endemic. Recently, CiLV-C was detected in Bolivia, Venezuela, and Colombia, and it is spreading northward through the countries of Panama, Costa Rica, Nicaragua, Guatemala, Honduras, El Salvador, and Mexico. This proximity and the potential damage that it can cause concerns the United States, where the disease has not been observed since the 1960s, and the Caribbean Islands, which are still leprosis-free. Until recently, one of the problems for citrus leprosis management was diagnosis, which has been based primarily on symptoms. That could be misleading, because other pests and pathogens may cause lesions similar to those associated with leprosis. For the same reason, reports of the disease in countries in Asia and Africa must be reviewed.