Elm bark beetles, Dutch elm disease and elm decline in St. Petersburg, Russia

Lead Author Andrey V., Selikhovkin
Institution Contact Saint Petersburg State University, Universitetskaya nab. 7-9, St. Petersburg, 199034, Russia and Saint Petersburg State Forest Technical University, Institutskiy per., 5, St. Petersburg, 194021, Russia
Co-Authors Boris G. Popovichev, Saint Petersburg State Forest Technical University, Russia; Dmitry L. Musolin, Saint Petersburg State Forest Technical University, Russia; Yuri N., Baranchikov, V.N. Sukachev Institute of Forest, Siberian Branch of the Russian Academy of Science
Theme Theme 1: Vulnerability of Arctic Environments
Session Name 1.7 Invasive species in Arctic ecosystems in the changing world: Is it a real threat?
Presentation Type Poster
Abstract text Dutch elm disease (DED) is caused by the fungus Ophiostoma novo-ulmi (Ascomycota), which is spread by elm bark beetles (Coleoptera: Curculionidae) during a period of feeding on shoots in early summer.

Ophiostoma novo-ulmi was accidentally introduced from Asia into North America and Europe in the 1940s. It devastated elms on both continents starting from the late 1960s (Spooner, Roberts, 2010). Shortly after the invasion, more than 25 million of trees died in the United Kingdom, whereas France lost over 90 % of its elms. The disease spread to all directions and reached Stockholm in the late 1980’s. Approximately 300–400 trees were removed annually to stop the spreading of the pathogen, but, nevertheless, in 2009, more infected trees than ever before were removed in Stockholm.

In St. Petersburg, the first decline of elms was recorded in 1995 in Tsarskoe Selo (the city’s southern suburb). Both the most common elms in St. Petersburg (Ulmus laevis and U. glabra) are declining now in all types of the city greenery objects because of the elm bark beetles Scolytus multistriatus and Scolytus scolytus and DED. These beetles were not significant pest in St. Petersburg before DED was recorded in the city (Venkova, 1938). Interaction of bark beetles and pathogen gave a catastrophic effect. Now more than 1500 loci of mass propagation of the pests and pathogen are known in all urban greenery objects in St. Petersburg including historical parks and squares.

Recently, another elm bark beetle Scolytus pygmaeus known to interact with the fungus was detected for the first time in St. Petersburg (Selikhovkin et al., 2014; Sherbakova, Mandelshtam, 2014).

Elms are popular in Northern urban greening because of their resistance to low temperature and urban stress. Spreading of the pests and fungal pathogen can dramatically impoverish the quality of the urban green decoration.