Greenhouses – urban biodiversity hotspot of alien Oribatida (Acari) species

Palm houses and other greenhouses, due to maintaining constant temperature and humidity, allow the cultivation in Europe of plants from different parts of the world, even from tropical regions. However, sometimes they are also a habitat for alien species of spiders, mites, insect, etc. These animals have been introduced accidentally with contaminated plants, seeds, seedlings, soil and thanks to stable conditions maintained in greenhouses, they may colonize these places. Example of arthropods, of which even tropical species occur in several greenhouses, are oribatid mites – minute saprophagous arachnids that mostly inhabit soil. In Europe they are represented by about 2,000 species, while worldwide – over 10,000 taxa were described. The aim of this research was to investigate the selected greenhouses for the biodiversity of oribatid mites and the presence of non-native species. In total, 49 taxa were recorded, including 23 alien species (for example, a Neotropical taxon Galumna hamifer, or Oriental Suctobelbella parallelodentata). These results confirm that greenhouses are the places of occurrence of many alien oribatid species. The obtained results may be used in future research on the biology of poorly known tropical mites.