The invasive spotted wing drosophila (SWD) is a well-known pest in agriculture. A recent study by Swiss scientists now shows that the forest ecosystem is also affected by this alien insect. SWD infests the fruits of various forest plants and competes with other fruit-eating species. The decay of fruits attacked by SWD leads to a loss of resources, which can cause considerable ecological damage.The invasive spotted wing drosophila (SWD) is a well-known pest in agriculture. A recent study by Swiss scientists now shows that the forest ecosystem is also affected by this alien insect. SWD infests the fruits of various forest plants and competes with other fruit-eating species. The decay of fruits attacked by SWD leads to a loss of resources, which can cause considerable ecological damage.