THE DISTRIBUTION OF BIRCH PHYLLOPHAGOUS INSECTS IN THE TERRITORY OF A LARGE INDUSTRIAL CITY
To date, there have been no studies on phyllophagous insects communities in the city of Yekaterinburg. Dividing the greenery of the city into 7 categories, we proposed to answer the following questions: to determine whether species richness and ecological structure of phyllophagous insects communities differ in various categories of urban greenery, and also to find the factors of essential deviations of some biotopes (points) from the mean city indices. The birch insect communities were chosen as objects for analysis. In 2008 birch phyllophagous insects communities in the Yekaterinburg territory were studied during two last ten-day periods of July, using trees in biotopes of categories chosen (45 points evenly distributed within the city boundaries). In each biotope, ten trees were inspected; all the noticed phyllophagous insects and their feeding marks in the lower part of tree crowns were registered. 81 phyllophages species were found; Lepidopterans are the largest taxonomic unit (37 species), and the ecological group of gnawing open living insects (26 species) prevails among phyllophages. It was shown that species richness and insect communities structure change insignificantly among different categories of urban greenery. However, the species richness of insect communities, species number of open living insects and their proportion in insect communities reduce in the streets of the city center. Three factors (high pollution of air and food plants (for biotopes of 6 and 7 categories); high shading of plants in biotopes (for 1-3 categories) and the young age of trees) reduce the species richness of phyllophagous insect communities and change their structure.