In 2002 the Asian buprestid Agrilus planipennis was discovered in Michigan, USA. The emerald ash borer had at that time already weakened or killed 5-7 million ash Fraxinus sp. trees. In its native range in East Asia the species was never considered a major pest. The lack of natural enemies and the lower resistance of Nearctic ash species to A. planipennis may explain its devastating expansion in North America. In 2007 A. planipennis was reported from Moscow, where it seems widely established on introduced Fraxinus pennsylvanica. A further European expansion is feared. However, it is yet unknown whether the European ash species are as susceptible as the American ones. Whether A. planipennis is capable of reproducing in the buprestid unfriendly Atlantic climate of the Netherlands is also not known.