Not a one-way street: yellow sugarcane aphid native to North America found in Europe
In the U.S. we may often forget that other countries have their own issues with invasive species. the yellow sugarcane aphid (Sipha flava) was recently found in northeast Spain in two different municipalities, La Selva del Camp (province of Tarragona) and Blanes (province of Girona) and is believed to have come to Spain by way of north Africa. While surgarcane is not a major crop in Europe, the aphid is known to feed on other species of grasses and it is not known what the impact may be on other important grass crops in Europe, such as rice and corn.
Sipha flava by Kansas Department of Agriculture Archive, Bugwood.org