Quarantine treatment against Anastrepha suspensa on grapefruit
Experiments carried out in Florida (US) have allowed the development of a forced hot-air quarantine treatment to kill eggs and larvae of Anastrepha suspensa (EPPO A1 quarantine pest) on grapefruit (Citrus paradisi cv. Marsh White). A forced hot air treatment, applied over the surface of grapefruits, at 48 + 0.3 øC during at least 150 min is necessary to heat the centre tissues at a temperature ; 44 øC, in order to eliminate eggs and larvae of A. suspensa and ensure quarantine security (probit 9). In addition, the effect of hydrocooling which is a procedure used by the industry in order to reduce the temperature of the fruits after a hot treatment (by water spray or immersion), was studied. The aim of hydrocooling is to delay fruit decay, to reduce surface scald, bronzing and pitting ; however, this treatment may also increase the number of fruit fly survivors. Further studies were then carried out, and the authors have found that if grapefruits were heated to 44.45 øC at the centre and then immersed in 10 øC water, the treatment was still effective for quarantine purposes.
Sources
Sharp, J.L.; Gould, W.P. (1994) Control of Caribbean fruit fly (Diptera: Tephritidae) in grapefruit by forced hot air and hydrocooling.
Entomological Society of America, 87 (1), 131-133.
Sharp, J.L. (1993) Hot-air quarantine treatment for 'Marsh' withe grapefruit infested with Caribbean fruit fly (Diptera: Tephritidae).
Entomological Society of America, 86 (2), 462-464.
Additional key words: phytosanitary procedure.