Study of the distribution of harmful insects in plantations of the lower Volga region, as one of the directions of improvement of entomological monitoring (using the example of the winter moth)

The spatial distribution of the winter moth was studied in the Lower Volga region in plantations with different forestry and taxonomic characteristics from 2020 to 2023. On test plots, the population of the moth was counted at different stages of development, its distribution in the tree crowns was studied, as well as its affinity for specific food species. The distribution of the pest was studied in plantations similar in density, depending on the distance of the trees from the edge of the forest: up to 30 m, from 30 to 60 m, and from 60 to 100 m. The research showed that in the plantations, the winter moth mainly settled on weakened trees. On 55 trees of the first health category, there were an average of 4.988 caterpillars, while on 57 trees of the third health category, there were 10.838 caterpillars per standardized accounting unit, or 100 growth points. As the distance from the edge of the forest increased, the number of winter moth caterpillars decreased. According to the research, significant infestation by the moth was observed on the English oak (4.27 caterpillars per standardized accounting unit), while lower infestation was observed on aspen and maple (an average of 0.52 and 0.63 caterpillars per standardized accounting unit, respectively). Through statistical analysis, parameters characterizing the features of the identified distributions were found. The distribution of insects in plantations, particularly the winter moth, allows for improving the efficiency of sampling programs, data analysis methods, and based on this, developing optimized entomological monitoring methods.