Состояние посадок ясеня пенсильванского Fraxinus pennsylvanica Marsh в Московском регионе после инвазии ясеневой узкотелой златки Agrilus planipennis Fairmaire (Coleoptera, Buprestidae)

Abstract

In 2017-2023 on the territory of Moscow region studied three types of plantings of Pennsylvania ash that survived the invasion of Agrilus planipennis in 2005-2012. All the trees damaged by the larvae A. planipennis. Most of the trees died (75%), the surviving trees remain the chronic ground of pests for twenty years. The surviving trees (25%) cropped, the assessment of their condition in 2017-2018 met the criterion of "weakened", in 2018-2023 – "severely weakened". The improvement in the condition of the trees in 2014-2018 replaced by a deterioration in 2021. Among the three types of plantings, the satisfactory condition of trees found in squares and multi–row plantings along streets, poor - in single-row plantings along streets. In the next decade most of the plantings along the streets degrade, other types of plantings remain. At the squares and parks of the center of the Moscow megalopolis, the trees partially restores the crown and partially overgrowing of old larval galleries on trunks. Damage by A. planipennis on multi-row plantings along highways provoked an outbreak of Leperesinus varius in 2006-2008. The synergy of A. planipennis and L. varius caused the rapid death of the Pennsylvania ash tree in the Moscow region. Trees trimmed to 1/3 of the crown and the "weakened" category live for at least 8 years, the "severely weakened" category – for at least 5 years. Removing from 1/3 to 2/3 of the crown is advisable only for trees of the "weakened" category. Removing more than 2/3 of the crown and topping with the removal of the top and skeletal branches leads to death of the tree. Keywords: GREEN ASH, EMERALD ASH BORER, HEALTH OF URBAN PLANTINGS