Comparing densities of spider mites (Tetranychidae) and predatory mites (Phytoseiidae) on the common oak (Quercus robur L.) in forests of natural and industrial areas

This paper presents results of studies conducted in the forest areas of the Polesie National Park and in the surroundings of the chemical producer Zakłady Azotowe in the town of Puławy on the abundance of mites from the families Tetranychidae and Phytoseiidae. These studies were conducted on eight different sites in the years 2002–2004 and aimed at answering the question of whether mite abundance is related to factors such as area, site and year. In total, 8894 specimen of the spider mite family and 1835 specimen of the predatory mite family were collected. Spider mites were more abundant in Puławy than in the Polesie National Park, whilst the abundances of predatory mites were similar in both study areas. For spider mites, statistically significant differences were found in terms of study area and site, but also in terms of the study area in relation to the year of investigation. In the case of predatory mites, statistically significant differences were also found in terms of the study area in relation to the year of investigation