Enemy of Spotted Wing Drosophila -Leptopilina japonica- now also found in the Netherlands

3-3-2026

The Asian parasitic wasp Leptopilina japonica has now also been found in the Netherlands. In previous years, the parasitic wasp was found in Italy (2019), Switzerland and Germany (2021), France (2022), Belgium (2022) and the United Kingdom (2024). The parasitic wasp, which originates from Asia, parasitises the dreaded spotted wing drosophila (Drosophila suzukii). In the summer of 2025, researcher Herman Helsen of Wageningen University & Research (WUR) also introduced Ganaspis kimorum, another natural enemy of the spotted wing drosophila, at five locations in the Netherlands. The hope is that these natural enemies will spread and together make an important contribution to the control of the spotted wing drosophila.

Found at 24 locations

Last summer, WUR examined fruit at 35 locations in the Netherlands for the presence of Leptopilina japonica. Populations of this parasitic wasp were found at 24 locations, sometimes in large numbers. A find in the province of Drenthe, in the north-east of the Netherlands, marks the northernmost limit of the species' European distribution range to date. The parasitic wasp is approximately 1.5 millimetres in size and highly specialised. It lays its eggs almost exclusively in young larvae of the spotted wing drosophila. 

Follow-up research 

Further research is being conducted to determine whether the parasitic wasp can sustain itself in commercial fruit orchards and to what extent it can independently suppress the population of the spotted wing drosophila. It is likely that L. japonica will follow the spotted wing drosophila from natural environments to cultivated areas on an annual basis. (Source: Wageningen University & Research (WUR))

Read the WUR announcement here