A combination radio frequency-hot water dip method was examined as

Efficacy of using radio frequency (RF) at 27.12 MHz was evaluated as a postharvest quarantine treatment against fifth instars of the codling moth [Cydia pomonella (Lepidoptera: Tortricidae)], in apples (Malus sylvestris). Tests under the given conditions demonstrated that the energy fields between the RF unit's electrodes were neither predictable nor uniform. Moving fruit submerged in water during RF exposure may improve uniformity, but pulp temperatures varied considerably among fruit, among sites on the same fruit, and at different depths within the same site. As a result of these inconsistencies, quarantine efficacy was not obtained either using a range of final average temperatures from 40 to 68 °C (104.0 to 154.4 °F) or at holding times up to 20 minutes. We concluded it would be difficult to obtain the appropriate parameters for treatment efficacy and fruit quality maintenance using this technology under these conditions.

ADDITIONAL INDEX WORDS. Cydia pomonella, heat treatment, quarantine, fruit quality SUMMARY. Quarantine regulations require domestic sweet cherries (Prunus avium) exported to Japan to be treated to control codling moth [Cydia pomonella (Lepidoptera: Tortricidae)]. The current procedure, methyl bromide fumigation, may be discontinued because of health, safety, and environmental concerns. To examine a potential alternative method, 'Bing' sweet cherries were each infested with a codling moth larva, submerged in a 38 °C water bath for 6 minutes pretreatment, then exposed to various temperatures generated by radio frequency and held at that temperature for different times: 50 °C for 6 minutes, 51.6 °C for 4 minutes, 53.3 °C for 0.5 minutes, and 54.4 °C for 0.5 minutes. Insect mortality was evaluated 24 hours after treatment and fruit quality was evaluated after treatment and after 7 and 14 days of storage at 1 °C. No larvae survived at the 50 and 51.6 °C treatments. Fruit color of non-infested cherries was darkened as temperature increased. Stem color was severely impacted after 7 days of storage, even in a warm water bath of 38 °C for 6 minutes, as was fruit fi rmness at the same treatment. Fruit quality loss increased after 14 days of storage, compared to after 7 days of storage. The amount of pitting and bruising of cherries increased with temperature and again this increase was more evident after 14 days of storage.

Codling moth [Cydia pomonella (Lepidoptera: Tortricidae)], found in exported apples (Malus sylvestris), can disrupt international markets. Cold storage at 1.1 °C was examined for possible control of three physiological larval states in ‘Fuji’ apples: diapausing (overwintering), diapause-destined, and nondiapausing. All nondiapausing larvae were dead within 12 weeks, diapaused-destined larvae were controlled by the seventh week, yet more than half of the original populations of diapausing larvae were still alive after 11 weeks. Because the diapaused-destined larvae were younger than the nondiapausing larvae, they may have been more susceptible to cold. Because larvae normally diapause outside the fruit, cold storage would not be applicable for controlling larvae in this state.

A radio frequency (RF) treatment, with a pulse mode to increase heating uniformity, was examined as a potential quarantine treatment against fifth instars of the codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), in apples, Malus sylvestris L. var. domestica (Borkh.) Mansf., intended for export to Japan. Apples were exposed in water baths to 27.12-MHz RF energy at 12 kW with a pulse mode of 30 s-on/30 s-off for different durations. The temperature uniformity was determined by measurements at 12 sites evenly spaced at two depths in the fruit. The most promising exposure time was 29 min. The efficacy of the treatment with the pulse mode was examined against the codling moth larvae by using exposures between 27 and 30 min and up to 30 min of holding time in bath after treatment. The treatment that killed all larvae with the least amount of energy was the 29-min exposure with 50-min holding time. This treatment was appraised for fruit quality in "Delicious" apples. Some injury was observed when treated fruits were removed from 1C storage after 30 days. When these fruits were held at 25C for 1 week, all were too damaged to evaluate for fruit quality. Although pulse mode increased heating uniformity in the fruit, the thermal 4 Corresponding