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

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