The effect of urban-rural gradient on black poplar endophagous herbivorous insects

With the process of urbanization and the development of cities, trees in the urban environment are becoming increasingly important. Those trees represent a habitat and a food source for many organisms, among which insects are the most numerous and diverse. The insect communities inhabiting them frequently differ from those found in the rural environment. However, the transition from rural to urban habitat is rarely sharp, as there are many intermediary habitats that often represent the species rich areas. We investigated how the urbanization gradient affects the black poplar endophagous herbivorous insect community. To determine that, we compared the leaf miner and gallicolous aphid species richness, abundance, and diversity along rural-urban gradients. The research was conducted in 2019, in three cities in Serbia, in rural, suburban, and urban areas. We concluded that urbanization significantly influences the black poplar leaf miner community, while it does not have a significant effect on the black poplar gallicolous aphid community. Significantly lower leaf miner species richness and diversity were recorded in the urban environment, while their abundance was significantly lower in suburban areas. Contrary to most species, Fenusella hortulana (Hymenoptera) reacted positively to urbanization, while Aulagromyza populi (Diptera) and Phyllonorycter extrematrix (Lepidoptera) were not significantly affected. As about 80% of leaf miner species and 40% of gallicolous aphid species still manage to survive in the urban environment, the trees present in the urban environment are important for the preservation of their fauna.