R.F. Lee

Tristeza, meaning sadness in Spanish or Portuguese, was the name first given to a decline of trees on sour orange rootstock in South America. Tristeza was later shown to be caused by Citrus tristeza virus (CTV), a member of the closterovirus group within the Closteroviridae. Seedling yellows disease is a synonym used for tristeza. CTV is probably the most destructive citrus virus in the world. There have been documented losses of about 30 million trees on sour orange rootstock in Brazil and Argentina in the 1940s and 1950s, of 6.6 million in Venezuela in the 1980, and an estimated 10 million trees in Florida and other Caribbean Basin countries, all these losses were due to the introduction of Toxoptera citricida, commonly called the brown citrus aphid (BrCA), which is the most efficient vector of CTV (Rocha-Pena et al. 1995). The BrCA has been increasing its geographical area throughout the Caribbean Basin since 1989 and was first found in Florida in November 1995 (Halbert, 1998). Even without the BrCA, CTV has killed about 10 million trees Spain (Cambra et al. 1988) and millions more which are not well documented in Israel, Florida, California and in other areas (Bar-Joseph et al. 1989).