Diversity structure of phytoseiid mites in urban plant habitats

Abstract

We founded that E. finlandicus and K. aberrans formed the nucleus of Phytoseiidae community on the plants of urbanized environment in the result of study of 93 plant species (55 species of tree-and-shrub (58.9%) and 38 species of herbaceous plants (41.1%). Our research was carried out in plantations along the main and secondary municipal highways, near residential area and industrial buildings, on private plots of the private building area, in city parks and squares of Kyiv, Uman, Brovary, and Vasylkiv (Ukraine). The peculiarities of their distribution among urban plant associations, which differ from each other by different characteristics (population, area, degree of urbanization) were determined. Both species - E. finlandicus and K. aberrans have a rather extended range of indicators of relative biotope contiguity (-0.91<Fij<0.43 and -0.93Fij<0.96) that indicated their property to inhabit large number of plants. The indicator of K. aberrans occurrence, which was the highest in the city with the smallest degree of urbanization (Vasylkiv), decreased in the city with the maximum possible degree of urbanization (Kyiv). This indicator of E. finlandicus on the contrary increased along the gradient from a smaller city to the metropolitan city. K. aberrans inhabit a large number of plant species (33 species), while preferred plants from Rosacea family. E. finlandicus dominated by number of urban plant species it inhabited (75 species, 79.78%), absolute number of individuals in collected samples of predatory mites (504), occurrences index (Is = 74.49%), and by index of Palii-Kovnatsi (Di = 51.42%). The dominance of E. finlandicus species was registered in both groups of plants. The distribution of Phytoseiidae’s was primarily connected with the possibility of their movement along the surface of the substrate. Speed of mites moving was not the same in different species and depended on their morphology and plant morphology. Both species lived and laid eggs on the underside of the leaf. K. aberrans was more commonly found near the central vein of the leaf, while E. finlandicus was observed more evenly on the leaf plate, which can be explained by it higher vagility. K. aberrans could inhabit high number on fruit varieties of plants with pubescence leaves. Morphological features of plant leaves did not affect the spread of E. finlandicus species, therefore, they could be considered more "universal". However, it reached a higher quantity on the plants with a smooth surface of a leaf plate. Certain temperature, illumination regime, air and soil humidity caused the differences in mites spreading at various habitats.