EPPO PRA for Drosophila suzukii
Both the PRA report and the full PRA record are available.
The EWG considered that the risk of entry was high with a low uncertainty for the main host fruits. The fact that the pest has established in Italy and France and was also introduced in the US and Canada was considered as a strong indication that the pest can enter easily. Volumes of imports are not large but the concentration of the pest is likely to be very high on the fruits. For minor host fruits, the risk is considered as medium with low uncertainty. The difference is due to the fact that the concentration of the pest is not likely to be very high on these hosts, and the fact that they are less likely to be infested than the major hosts.
The risk of establishment was considered to be high with a low uncertainty. This is due to the fact that host plants are widely present in the PRA area (cultivated but also backyard plants). Climatic conditions are suitable (only northern areas of Europe and Russia where hosts are present are unsuitable). The management practices can be adapted but the experience so far in the parts of the PRA area where the pest has established was that they could not prevent D. suzukii’s establishment. The EWG debated whether this should be considered very high but as the PRA area included parts where climate is not suitable (see above), the final conclusion was high.
The risk of spread is considered high with a low uncertainty Spread noted so far is a consequence of both human and natural spread. Human spread is very likely but the natural spread capacity is uncertain. The EWG decided to rate the probability of spread as 'high', though not 'very high', for that reason. Drosophila suzukii was first reported in North America in 2008 in California and by 2009 was widespread in a range of hosts from Oregon, Washington (Hauser et al., 2009) and British Columbia (BCMAL 2009). This demonstrates the ability of Drosophila suzukii to spread if suitable hosts are present and climatic conditions are favourable. The pest has also spread in France (EPPO, 2010c).
The EWG concluded that the potential for economic consequences due to D. suzukii incursions were high with a low uncertainty. The EWG was confident that when establishment occurs, damage is almost certainly going to be high initially. Management and experience, or even the fact that growers could change their agricultural systems and grow different crops altogether, may well reduce damage levels in the future.
- Bosnia and Herzegovina
- Czech Republic
- United Kingdom