Expansion of the invasive range of Agrilus planipennis in Russia
In 2018 and 2019, studies were conducted in Russia to monitor the north-western limit of the invaded range of Agrilus planipennis (Coleoptera: Buprestidae – EPPO A2 List). In June 2018, 10 study plots were established along a highway (M10) that runs from Moscow to Saint Petersburg via the city of Tver (approximately 180 km from Moscow). This highway is lined with ash trees (Fraxinus spp.). On each plot, 2-4 F. pennsylvanica trees were girdled by removing a band of 50 cm of the bark around their trunks to attract flying adults of A. planipennis. In addition, sticky traps (purple and dark-green) were placed around trunks. These study plots were examined in September/November 2018, and in October 2019. Results showed that the north-western limit of A. planipennis corresponds to the north-western border of the city of Tver, and that this limit has not significantly changed since observations made in 2015-2018. It is noted that despite the fact that F. pennsylvanica and F. excelsior are widely planted in the city of Tver and along nearby roads, population density of A. planipennis remained low. In Tver, many ash trees are damaged by the insect, but damage remains localized and massive dieback of ash trees is not observed. Considering the recent detection of A. planipennis in Saint Petersburg (EPPO RS 2021/009) which is approximately 520 km from Tver, it is considered that this new expansion towards the northwest does not result from natural spread but from accidental introduction. The insect might have been transported by vehicles, infested plants for planting and/or other commodities. The Saint Petersburg’s outbreak, which is approximately 130 km from Estonia and Finland, shows that the pest is approaching the European Union borders from the east, threatening ash trees. The authors concluded that measures are urgently required to contain and control the pest, as well as regular monitoring.
Sources
Musolin DL, Selikhovkin AV, Peregudova EY, Popovichev BG, Mandelshtam MY, Baranchikov, YN, Vasaitis R (2021) North-Westward expansion of the invasive range of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) towards the EU: from Moscow to Saint Petersburg. Forests 12, 502. https://doi.org/10.3390/f12040502