Drosophila suzukii
Common names: Cherry fruit fly, Cherry vinegar fly, or Asian vinegar fly, SWD
Family: Drosophilidae
Spotted wing drosophila is native to East Asia. Since its first detection outside its native range in the late 2000s, it has spread rapidly and is now established across much of North America, Europe, and other fruit-growing regions worldwide, including parts of southern Africa, where it presents an emerging concern for the soft fruit and berry industries.
This fly is closely related to the common vinegar fly familiar from ripe fruit and compost, but differs in one critical way: male flies carry a distinctive dark spot near the tip of each wing, and (unlike most vinegar flies) females possess a large, saw-toothed ovipositor. This serrated structure allows the female to cut into the skin of ripening, still-firm fruit rather than waiting for fruit to overripen or split, which is what makes this species such a serious agricultural pest rather than a harmless nuisance fly. A female can lay several hundred eggs over her lifetime, and under warm conditions the full life cycle from egg to adult can be completed in under two weeks, allowing numerous overlapping generations through a single growing season.
Life cycle of the spotted wing drosophila.
Spotted wing drosophila attacks a wide range of thin-skinned, soft fruit, particularly berries (such as raspberries, blueberries, and strawberries) and stone fruit including cherries, as well as grapes in some regions.
Because females lay eggs in fruit that is still ripening rather than overripe, damage is often invisible at the time of egg-laying and only becomes apparent once larvae are feeding inside the fruit, causing it to soften, collapse, and become vulnerable to secondary fungal and bacterial rot. There is effectively no acceptable damage threshold in fresh fruit destined for market, since even a small number of larvae render fruit unsellable, making this one of the more economically punishing soft fruit pests to manage.
Because damage occurs before fruit ripens fully, early detection through trapping is essential to time control measures correctly, alongside frequent, thorough harvesting to remove ripening fruit from the field before flies can lay eggs, and destruction of fallen or unharvested fruit that would otherwise serve as a breeding source.
Insect Science solution: Insect Science supplies a dedicated S.W.D. PheroLure®, used with a McPhail Trap or other suitable dry trap, for monitoring spotted wing drosophila. The solution is intended for monitoring pest activity and population dynamics in berries, grapes, other susceptible crops, home gardens, and non-crop situations as part of an Integrated Pest Management programme.
