The paper presents the results on resistance of Aesculus hippocastanum Linnaeus, 1753 trees to Cameraria ohridella Deschka & Dimić, 1986 (Lepidoptera, Gracillariidae) impact under conditions of a modern urban environment on the example of Dnipro city as the largest industrial city in Ukraine. Field experiments were conducted in all park areas of the city, which allowed covering the full gradient of the existing urban environment and considered the different degrees of the tree settlement by the invasive insect species. The research of the impact of C. ohridella caterpillars’ vital activity on the photosynthetic apparatus state was carried out by applying a chlorophyll fluorescence induction technique. Diagnosis of photosynthetic dysfunction of fresh Ae. hippocastanum leaves was conducted using a portable “Floratest” fluorometer manufactured in Ukraine. Interpretation of the obtained Kautsky curves showed that significant changes in their critical parameters associated with the degree of leaf damage by C. ohridella caterpillars were not detected. The influence of tree growth site conditions on the following 4 main indicators of chlorophyll fluorescence induction was established: the initial value of fluorescence induction after irradiation; the value of “plateau” fluorescence induction; the maximum value of fluorescence induction; the stationary value of fluorescence induction after light adaptation of the plant leaf. It was found that the efficiency coefficients of photochemical processes in Ae. hippocastanum trees growing in low terrain levels differed significantly, which can probably be interpreted as their response to the specific characteristics of the urban environment.

This chapter is devoted to elucidating the bioecological characteristics of the existence of five invasive leafminer moth species of the family Gracillariidae Steinton, 1854 (Parectopa robiniella (Clemens, 1863), Phyllonorycter issikii (Kumata, 1963), Phyllonorycter platani (Staudinger, 1870), Macrosaccus robiniella (Clemens, 1859) and Cameraria ohridella Deschka Dimic, 1986) and extent of their impact on dendroflora in Ukraine. Features of their invasion into various ecosystems were revealed. The effects of Gracillariidae caterpillar feeding on host (food) plants were studied. The caterpillars of invasive leafminer moth species affected the functional state of host plants; it was confirmed by alterations in the content of soluble proteins, activity and isoenzyme composition of benzidine peroxidase during the growing season of the host plants. The study of dynamics of highly soluble proteins showed a decrease in their content at substantial leaf damage. The restructuring of both peroxidase activity and its isoenzyme profile was revealed to be indicators of the plant biochemical adaptation to the feeding of caterpillars of invasive leaf blotch miners. The results obtained show the activation of the enzymatic antioxidant protection system in host plants in response to the damaging effect of Gracillariidae caterpillars, which ensures the survival of the plant and completes its ontogenesis program in unfavorable conditions.