The South African Citrus Psyllid, Trioza Erytreae (Del Guercio)

The psyllid, Trioza erytreae (Del Guercio), is an important pest of citrus in southern africa where heavy infestations can cause economic injury to new growth, particularly that of nursery stock, by producing pitting, curling, and stunting of leaves. More importantly, this psyllid is a vector of the mycoplasma-like organism that causes greening disease. Greening was described by Rossetti (1975) as “the most serious citrus problem in South Africa where it affects the major citrus species irrespective of rootstock, reducing yields and making a higher percentage of fruits worthless.” Neither greening nor the vector T. erytreae presently occurs in the United States and perhaps not in the new world; however, diseases-similar to greening (more likely the closely related citrus stubborn disease) have been reported from South America (Brazil, Argentina, Peru). The leafhopper-vectored California stubborn already is a problem in “hot areas” of California and Arizona where Bove et al (1974) reported symptom expression as severe.

The Asiatic citrus psyllid, Diaphorina citri Kuwayama, the vector of greening in the orient, was reported from Brazil by Costa Lima (1942). Quarantine officials should be alert to the possible importation of diseased citrus nursery stock and psyllid vectors originating from infested countries.