Comparative analysis of damaged ash stands by Agrilus planipennis Fairmaire, 1888 (Coleoptera: Buprestidae) in Penza

Abstract

In 2024, a dangerous invasive pest was detected for the first time in Penza Oblast — emerald ash borer Agrilus planipennis Fairmaire, 1888. The aim of this study was to assess the sanitary condition and compare the susceptibility of various types of ash stands in Penza. The study was conducted in 2025 in 27 stands, divided into three categories: residential plantings, roadside strips, and public gardens. A total of 354 green ash trees (Fraxinus pennsylvanica Marshall) were inspected. A sanitary category was determined for each tree, a weighted average sanitary condition category was calculated for each stand, and the resulting data were processed using parametric and nonparametric statistical methods. It was found that the sanitary condition of urban stands ranged from weakened to dying. No statistically significant differences in the damage degree were detected between residential, roadside, and public garden plantings, suggesting a uniform infestation of all urban stand types. No presence of the emerald ash borer was detected in natural forests of Penza Oblast during forest pathology monitoring; however, the risk of its introduction from roadside shelterbelts is noted. Ichthyophages of the Braconidae family, which are considered potential biological control agents, were recorded on affected trees. The obtained data show the high degree of threat to ash stands in the region and the need for further monitoring.