The Focus of the Emerald Ash Borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in Tver, on the Northwestern Border of the Invasive Range

Abstract

The emerald ash borer is a serious pest of ash (Fraxinus spp.) in North America and European Russia. It was introduced to those territories from East Asia in the 1990s. Currently the pest has spread in 12 regions of European Russia. The northwestern border of its range is in the city of Tver. This poses a potential threat to ash trees of St. Petersburg and Western Europe. In 2016 and 2018, green ash trees were surveyed in the summer in several districts of Tver. There are only local foci of the emerald ash borer in the city; mass drying of ash trees is not observed. A species that accompanies the emerald ash borer (the jewel ash beetle Agrilus convexicollis) and a pest parasitoid (Spathius polonicus) were found. Both species are recorded for Tver region for the first time. In addition, parasitoid Coeloides sp. was found inside the bark beetle galleries.