Accidental introduction of a biological control agent of Cydalima perspectalis in the EPPO region
Cydalima perspectalis (Lepidoptera: Crambidae) is an invasive pest of ornamental and wild box trees (Buxus spp.) in the EPPO region and beyond. In the Republic of Korea, which is the native range of C. perspectalis, an unidentified species of Eriborus (Hymenoptera: Ichneumonidae) is an important larval parasitoid of C. perspectalis and could be considered as a potential biological control agent of the pest in the invasive range. In spring 2024, an Eriborus sp. adult was caught in a botanical garden in Basel, Switzerland. The specimen was morphologically similar to the Eriborus species described as a parasitoid of C. perspectalis in the Republic of Korea. Further surveys were conducted in Switzerland and Germany and cocoons of Eriborus sp. were obtained from 10 out of 13 sites surveyed. Parasitism rates were high in several wild box tree stands, reaching 68% in Grenzach-Wyhlen (Baden-Württemberg, Germany) and 32% in Liestal and Füllinsdorf (Canton Basel-Land, Switzerland). This accidental introduction of a classical biological control agent may help to reduce the population of the pest, however, such accidental introductions can present regulatory challenges and concerns that the accidental introduction has not undergone a stringent safety evaluation as would be conducted in a biological control programme.
Sources
Kenis M, Klopfstein S, Lee M, Lee S, Seehausen ML (2025) Will an accidentally introduced parasitoid save European box trees? CABI Agriculture and Bioscience 6:1, 0081 https://doi.org/10.1079/ab.2025.0081