Abstract
The invasive African psyllid, Trioza erytrea, transmits the causal agent of the African form of citrus huanglongbing (greening) disease, Liberibacter africanum, a very destructive disease of citrus plants. It does this under natural conditions in Africa and the Middle East, and has been shown experimentally to transmit the Asian form, Liberibacter asiaticum. The psyllid itself severely distorts leaves, which become stunted and galled. T. erytreae affects species in the family Rutaceae, occurring on wild hosts as well as on Citrus species. T. erytreae is listed as an A1 quarantine pest by EPPO (OEPP/EPPO, 1988) and is also a quarantine pest for CPPC and OIRSA. The importation of plants for planting and cut branches of citrus from countries where either citrus greening bacterium or either of its vectors occur has been prohibited (OEPP/EPPO, 1990). T. erytreae occurs in Africa and parts of the Middle East but could probably establish and spread in Mediterranean countries without difficulty. Besides its role in citrus greening, the psyllid has itself significant damage potential.