Bucculatrix ainsliella Murtfeldt, a new North American invader already widespread on northern red oaks (Quercus rubra) in Western Europe (Bucculatricidae)

Bucculatrix ainsliella Murtfeldt, 1905 is for the first time reported from Europe: the Netherlands, Belgium, and adjacent Germany. DNA barcodes confirm its identity. It is the first North American lepidopteranspecies feeding on northern red oak Quercus rubra ever found in Europe, and only the second North American oak-feeding insect found in Europe. The species has regularly been found in the Netherlands and northern Belgium since 2006, and in 2011 also in Nordrhein-Westfalen in Germany, adjacent to the Dutch border, but the earliest records are from the Netherlands, Amersfoort in 1989 and 1990. Early stages, leafmines, and the adult are described, illustrated, and diagnosed against oak-feeding Bucculatrix ulmella Zeller, 1848 and other similar species. The biology and distribution are discussed. This species can be abundant in Europe, but significant damage has not been observed.