Asian hornet in Flanders: expand and support Vespa-Watch platform and research on management measures

The Asian hornet (Vespa velutina) has been present in Europe since 2004. The species is on the European list of invasive species of concern (European Regulation 1143/2014), which requires member states to take measures. The species has been present in Flanders since 2017. Since then, the species has greatly increased in number despite intensive management efforts. Currently, the species is widespread in Flanders, but with higher densities in the western part of the country, where the invasion started from France. It is considered as established.

In 2019, the citizen science project Vespa-Watch was launched by INBO and Honeybee Valley, and with financial support from EWI, to map the invasion of the species in Flanders. Since the start of the invasion, every active nest until 1 November 2022 has always been destroyed after notification. However, there is always a proportion of nests that are not found. Despite intense management efforts by the Flemish government, a sharp increase in the number of nests is noticeable. With this increase also comes an increase in management costs. This practice is no longer sustainable.
Additional research is needed to determine a realistic management target. How can the impact of this species on biodiversity be reduced? What effect has control (had) on the species' invasion rate and what are the future dynamics of the species in Flanders as a function of applied management?