COMMODITY TREATMENT AND QUARANTINE ENTOMOLOGY Host Status of Avocado (‘Hass’) to Ceratitis capitata, Ceratitis rosa, and Ceratitis cosyra (Diptera: Tephritidae) in South Africa

Ceratitis capitata (Wiedemann), Ceratitis rosa Karsch, and Ceratitis cosyra (Walker) (Diptera: Tephritidae) are pests potentially associatedwith avocado (Persea americanaMill.) in South Africa. The aim of the studywas to determine the host status of ÔHassÕ avocado to these tephritid pests over 4 yr. Unpunctured harvested avocadowas exposed to fruit ßies in the laboratory under no-choice conditions for 24 h. In Þeld studies, each species was exposed for 48 h under no-choice conditions to avocado attached to the tree. Fruit was harvested immediately, 4, 8 and 18 d after exposure. In all the experiments, the fruitwas incubated at 25 Cfor 49d after harvest.Hass avocado fruitwas sourced from pack-houses throughout the avocado production areas and inspected for any internal pests. Similar inspections were done from 2005 to 2008 at arrival in Europe following standard export procedures. Analysis indicated that Hass avocado is a conditional nonhost for C. capitata and a poor but potential host for C. rosa and C. cosyra. No requirement for a risk mitigation treatment for C. capitata on South African Hass avocado was found. Fruit sampling data did not produce any infested fruit, suggesting that natural conditions and/or existing procedures functioning in a systems approach are likely to mitigate the quarantine risks of C. rosa and C. cosyra on Hass avocado in South Africa.