After oviposition by Drosophila suzukii, the female leaves behind a small puncture in the fruit, through which the egg’s fine respiration tubes may extend—though these are often difficult to detect with the naked eye. As larvae begin feeding within the fruit, the internal tissue starts to break down, eventually leading to fruit collapse. Even when structural collapse is not visible, the presence of larvae renders the fruit unmarketable. The initial puncture sites also create an entry point for secondary pathogens such as bacteria, fungi, and yeasts, accelerating fruit spoilage. Additionally, compromised fruit becomes more attractive to other Drosophila species, compounding the damage. D. suzukii has a broad host range, but thin-skinned berries—such as raspberries, blackberries, blueberries, and strawberries—as well as stone fruits like cherries and plums, are particularly vulnerable to infestation.

Adult spotted-wing drosophila (Drosophila suzukii) are small fruit flies, measuring approximately 2–3 mm in length with a wingspan of 6–8 mm. Males are typically smaller than females and can be easily identified by the presence of a distinct dark spot on each wing—a key characteristic that gives the species its common name. Females lack wing spots but are distinguished by a robust, saw-like ovipositor, which allows them to pierce the skin of healthy, ripening fruit to deposit their eggs inside. The eggs are small, white, and measure around 0.6 mm in length and 0.2 mm in width, each equipped with two respiratory tubes that may protrude slightly from the fruit surface.

Larval development occurs entirely within the host fruit. There are three larval instars, with the third instar reaching up to 3.9 mm in length. Feeding by the larvae causes the fruit tissue to soften and collapse, significantly reducing marketability. Pupation can occur either fully or partially within the fruit, or externally on the ground. Pupae are tan to brown in colour and approximately 3 mm long.

Unlike most other Drosophila species that prefer overripe or damaged fruit, D. suzukii females actively seek out firm, healthy, and even unripe fruit for oviposition. This key behavioural trait makes the species particularly damaging to a wide range of thin-skinned and stone fruits, and a major concern for fruit producers globally.

An effective prevention strategy for managing Drosophila suzukii (spotted wing drosophila) involves the use of species-specific monitoring and trapping tools designed to detect early pest activity and reduce population pressure before fruit ripening. One such tool is the Drososan Trap, which is particularly useful for early-season monitoring. This trap consists of a red insect reservoir with four mesh-covered openings, a transparent lid, and a hook for easy hanging. The mesh design prevents the entry of non-target insects, including pollinators and beneficials, making it safe for use in diverse crop systems.

The Drososan Trap works by attracting adult D. suzukii with a liquid lure placed inside the trap. Once inside, the flies are unable to escape and eventually drown in the solution. To be effective, the trap must be used with an appropriate attractant, ideally consisting of 200 ml of solution per trap. A common base formula includes 1/3 water, with additional attractant ingredients such as apple cider vinegar, yeast, sugar, or commercially available lures to enhance its attractiveness. It's important to avoid placing the trap in direct sunlight, as high temperatures may reduce the efficacy of the attractant.

The trap is most effective when installed early in the season, as soon as temperatures exceed 10°C. This coincides with the beginning of adult flights and early fruit development in surrounding host plants. At this stage, few natural food sources are available, making the lure more competitive. However, once fruit begins to ripen, the trap's attractiveness may decline, as real fruit becomes a more powerful draw for adult flies.

In addition to liquid-based trapping, red sticky cards can be deployed to enhance monitoring. These are particularly useful for detecting adult activity at the canopy level. Red is known to attract D. suzukii, and the sticky surface captures flying adults upon contact. Sticky cards provide a visual indication of pest presence and flight intensity, helping to guide decisions on further intervention, such as exclusion, sanitation, or biological control.

By combining the Drososan Trap and red sticky cards with other integrated pest management strategies, growers can detect and reduce D. suzukii populations before they reach damaging levels—ultimately protecting crop quality and marketability.