Woolly ash aphid Prociphilus fraxinifolii (Riley, 1879) (Hemiptera: Eriosomatidae), a new invasive alien pest of ash trees (Fraxinus) in Russia.

Woolly ash aphid or ash leaf curl aphid Prociphilus fraxinifolii (Riley, 1879) is an alien invasive pest of ash trees native to North America. After its first record in Europe in 2003 in Hungary it has spread to the Ukraine, Serbia, Bulgaria, Great Britain, Spain, Poland and Germany. In 2016 P. fraxinifolii was firstly recorded at the southwestern border of Russia. Now Prociphilus fraxinifolii is firstly recorded in the center of European Russia, namely in Moscow Region, which is more than 700 km far from all other known localities of the species. In September 2017 five groups of ash trees (Fraxinus pennsylvanica) with colonies of Prociphilus fraxinifolii were found in Moscow Region. The example of Prociphilus fraxinifolii shows that alien pest insects can spread in Europe very quickly. Now Moscow region is the only regions of Europe, where the expanding range of Prociphilus fraxinifolii has overlapped with expanding ranges of other invasive alien species established in Europe in the last 20 years and severely damaging ash trees: ash dieback fungus Hymenoscyphus fraxineus Baral et al., 2014 (Ascomycota) and emerald ash borer Agrilus planipennis Fairmaire, 1888 (Coleoptera: Buprestidae).