Alien eating alien - rapid spread of Aceria fraxiniflora, a non-native gall mite of the invasive green ash (Fraxinus pennsylvanica) in Central-Eastern Europe.

The North American gall mite Aceria fraxiniflora was first recorded in Europe in southeast Hungary in 2017. Since then, it has shown a remarkably rapid spread on its host, the also North American green ash (Fraxinus pennsylvanica). By the beginning of 2023 it has been recorded in eight Central-Eastern European countries.