Postharvest short cold temperature treatment to preserve fruit quality after Drosophila suzukii damage

Blueberry (Vaccinium corymbosum) and strawberry (Fragaria ananassa) are fruits heavily colonised by Drosophila suzukii in the field while damage increases considerably during the postharvest period. In order to reduce the damage, a short exposure to low temperature can be used to limit the survival of D. suzukii eggs and to prevent the decline in quality of infested fruits. Berries were artificially infested and kept at 0.5 and 5.0 degrees C for 10 and 24 hours. Damage was visually assessed at 3, 6, and 9 days and emergence of flies considered. Berries treated with 0.5 degrees C for 24 h had a higher reduction in emergence of adults in both blueberry (83%) and strawberry (59%) and lower fruit damage. The treatment prolonged the shelf life of infested fruits up to 6 days in blueberry and 3 days in strawberry, compared to untreated control. A direct relation was found between the number of emerging adults and the decay index. It is concluded that short cold temperature exposures would be helpful in order to constrain pest development and sustain berry marketability.