Browsing by Subject "aasianrunkojäärä"

Asian longhorned beetle (Anoplophora glabripennis Motschulsky) is an invasive alien species native to China and Korea. Asian longhorned beetle has been established on many European countries, United States and Canada. The pathway to the new environments is typically via solid wood packing material (SWPM) which is used especially to pack stoneware. The larva lives inside the trunk and chews tunnels. These tunnels may result in loss of turgor pressure and, by implication, to loss of leaves and finally to death of the tree. Eradication of this species is complicated due to a wide range of host species. The first introduced population in Finland was discovered in October 2015 in the municipality of Vantaa, near to Helsinki. Thus, we have a lack of knowledge in its habits in Finnish circumstances. The main objective of this thesis was to specify whether the Asian longhorned beetle is established also in Helsinki and which areas would be potential habitats for this species. Because no Finnish research about this pest has been published, also a literature survey about the species is provided. Areas, where stoneware originated to Asia is stored at the moment or was stored before, were considered as a potential habitats for the Asian longhorned beetle. The observations were conducted during the summer season 2016. The potential host trees were observed with binoculars. Inspections focused on searching round exitholes typical to the Asian longhorned beetle from the trunk and the main branches. Trees with suspicious holes were felled and investigated. No Asian longhorned beetles were found. However, there are several potential areas in Helsinki. In total, 35 potential areas were inspected. These areas were rich in broadleaved trees that belong to hosts of this pest. It can be assumed that Asian longhorned beetle would not have shortage in suitable host trees. The most common inspected tree species were silver birch, dawny birch, European aspen and goat willow. Ground inspection with binoculars is a common, but unreliable method. In summer time foliage layer may obscure the visibility to the trunk and the branches. On the other hand, trees with dead branches or a lack of foliage can be easily detected and thus special effort can be used to inspect these trees. It can be suggested that at least not very old or high density populations exist in Helsinki. The best way to avoid new introductions is to favor Finnish stoneware and avoid Asian wood packing material. The treatments of SWPM should be improved to prevent further spread of these pests. The omission of treatment should never happen. One option is to replace SWPM with more secure packing materials. Also the destruction of the packing material should be carried out properly and it should not be transported for example as a firewood to summer cottages. This study was carried out together with University of Helsinki and Public Works Department of the city of Helsinki. Cooperation was done also with the Finnish Food Safety Authority Evira.