Postharvest quarantine treatments for Drosophila suzukii in fresh fruit

Abstract

Certain countries have imposed restrictions on the trade of fresh fruit due to possible infestation by Drosophila suzukii. A stand-alone postharvest treatment is often the simplest means to provide quarantine security against D. suzukii. With respect to stand-alone postharvest fumigation, efficacious parameters for methyl bromide and phosphine have been published, while those for ethyl formate are ongoing. Cold treatments have been developed for several types of fruit, with durations lasting 12-14 days at <1 °C. D. suzukii in fruit subjected to irradiation at a dose of 80 Gy were unable to produce F1 adults. System approaches combining multiple postharvest treatments have also been implemented, primarily in the context of reducing time and dosage requirements of the stand-alone treatments as well as harnessing control measures intrinsic to the commercial marketing of fruit (e.g., packing-line sorting, fungicide application, and in transit cold storage). The phytosanitary approaches cited above must be compliant with the regulations at the location of treatment and, as is the case for any phytosanitary treatment proposed for international trade, the importing country issues approval based on risk assessments and other regulatory considerations (e.g., residue tolerances, consumer exposure, and environmental health).