Artikkelit jotka sisältää sanan 'vieraslajit'

Ash (Fraxinus excelsior L.) is a relatively rare tree species in Finland, as it is common only in the southernmost part of the country although its distribution area ranges up to Oulu region. Finnish ash trees were free of dangerous pests and pathogens until 1990´s when an ascomycete Hymenoscyptus fraxineus (T. Kowalski) Baral, Queloz & Hosoya causing ash decline was introduced to Europe and changed the situation. Thereafter also hymenopteran Tomosthetus nigritus Fabricius has become more common in Finland due to an unknown reason and can now be considered harmful on the health of ash trees. In addition, the emerald ash borer, Agrilus planipennis Fairmaire, that has caused considerable damage especially in North America, has become a threat to ash trees as it is spreading in Russia towards Finland. In this review we will describe the biology and control possibilities of these three organisms and their distribution history in Finland and elsewhere.

• Hantula, Luonnonvarakeskus (Luke), Luonnonvarat, Helsinki https://orcid.org/0000-0002-1016-0636 Sähköposti: jarkko.hantula@luke.fi
• Koivula, Luonnonvarakeskus (Luke), Luonnonvarat, Helsinki https://orcid.org/0000-0001-6415-4904 Sähköposti: matti.koivula@luke.fi
• Nuorteva, Luonnonvarakeskus (Luke), Luonnonvarat, Helsinki https://orcid.org/0000-0002-8211-9843 Sähköposti: heikki.nuorteva@luke.fi
• Ylioja, Luonnonvarakeskus (Luke), Luonnonvarat, Helsinki https://orcid.org/0000-0002-8840-7504 Sähköposti: tiina.ylioja@luke.fi