Het lieveheersbeestje Harmonia axyridis in Nederland: een aanwinst voor onze fauna of een ongewenste indringer (Coleoptera: Coccinellidae)?

Harmonia axyridis in the Netherlands: a gain for the fauna or an unwanted intruder (Coleoptera: Coccinellidae)? The coccinellid Harmonia axyridis (Pallas, 1773), a well-known aphid predator originating from Asia, was found for the first time in the Netherlands (Heilige Landstichting near Nijmegen) in 2002. During 2003, the species was collected at several localities in the southern part of the country. In the surroundings of Tilburg and Rotterdam the species is already considered as common. Its establishment could be the result of either survival of independently released (or escaped) specimens for biological control (very likely for the population in Rotterdam), or a colonisation from Belgium were outbreaks of H. axyridis were recorded in the preceding years (likely for the surroundings of Tilburg). Risks and regulations with respect to the introduction of exotic species as biological control agents of pests in indoor and outdoor cultures are discussed. Recently, regulations have been sharpened in the Netherlands, but they are too late to prevent the establishment of H. axyridis, wanted or not. Once an exotic species has established itself it is virtually impossible to get rid of it.