Drosophila suzukii – experiences from the fly's northernmost inhabited region (from the first record to two years after the detection)

Abstract: Spotted wing drosophila (SWD), Drosophila suzukii, was recorded for the first time in the Nordic region in the county of Scania, southern Sweden, in late summer 2014. Inventory work has been carried out in 2015 and 2016 with focus on two main objectives, the spread and the potential for the subsequent economic consequences. Raspberries, blackberries, blueberries, strawberries, elderberries, red currants, cherries, plums and grapes were included in the survey. In 2015, the first flies were recorded during week 32. Varying numbers of catches were recorded all over the Scania county but not in any other regions. The highest level of catches was observed during the period of week 42 to 44. Maximum captures, 42 and 62 flies per week and trap, were observed in plums and autumn fruiting raspberries respectively. In 2016, the fly has been found in three new regions. The first specimen was cached in week 29 in cherries and maximum captures, 170 flies per week and trap, were obtained in week 40. The fly occurrence was observed until the middle of December. Eggs and/or larvae were found in fruits and berries in all the crops and plants that have been monitored during both years. The damage caused by SWD larvae was however very limited. An integrated management approach was implemented in 2016. A focus group bringing together scientists, advisers and farmers has been formed, working on tools for site specific risk assessment and integrated control.