FORCED HOT-AIR QUARANTINE TREATMENT FOR GRAPEFRUIT INFESTED WITH MEXICAN FRUIT-FLY (DIPTERA, TEPHRITIDAE)

Grapefruit, Citrus paradisi (MacFadyen), were infested artificially with late third instars of Mexican fruit fly, Anastrepha ludens (Loew), and treated with forced hot air until the fruit-center temperatures were 48 degrees C. Artificially infested fruit heated more slowly than uninfested fruit The forced hot-air treatment used an incremental air-temperature increase, with humidity controlled to maintain a dew point that was 2 degrees C lower than the fruit surface temperature. This procedure prevented fruit damage resulting from scald by condensation and by desiccation. In total, 102,037 larvae in 2,488 fruit were killed, thus exceeding probit-9 mortality (99.9968%) requirements. The treatment did not affect significantly fruit appearance or flavor quality ratings, although ratings for flavor and overall preference were lower for treated late-season, commercially stored fruit.