No abstract

Unstable microhabitats (merocenoses)—such as decayed wood, ant hills, bird and mammal nests—constitute an important component of forest (and non-forest) environments. These microhabitats are often inhabited by specific communities of invertebrates and their presence increases the total biodiversity. The primary objective of the present study was to compare communities of Uropodina (Acari: Mesostigmata) inhabiting soil and unstable microhabitats in order to explore the specificity of these communities and their importance in such ecosystems. Uropodine communities inhabiting merocenoses are often predominated by one or two species, which constitute more than 50 % of the entire community. Many species occur commonly in particular merocenoses, but are absent or rare in soil and litter, for example, Allodinychus flagelliger, Metagynella carpatica, Oplitis alophora, and Phaulodiaspis borealis. The biology of Uropodina inhabiting unstable microhabitats is modified by the adaptations required for living in such habitats. Mites associated with merocenoses developed special dispersal mechanisms, such as phoresy, which enable them to migrate from disappearing environments. Communities of Uropodina in soil and litter predominately consisted of species which reproduce parthenogenetically (thelytoky), whereas in merocenoses bisexual species prevail.

The fauna of Mesostigmata in nests of the white stork Ciconia ciconia was studied in the vicinity of Poznań (Poland). A total of 37 mite species was recovered from 11 of the 12 nests examined. The mite fauna was dominated by the family Macrochelidae. Macrocheles merdarius was the most abundant species, comprising 56% of all mites recovered. Most of the abundant mite species were associated with dung and coprophilous insects. It is likely that they were introduced into the nests by adult storks with dung as part of the nest material shortly before and after the hatching of the chicks.

Abstract. This study determined the scale of the phoresy of mesostigmatid mite by Ips typographus. Thirty pheromone traps in the Karkonosze National Park (Poland) caught 10,575 bark beetles on which there were 2,388 mesostigmatid mites belonging to eight species. The most numerous mites were Dendrolaelaps quadrisetus (1076 ind.) and Trichouropoda polytricha (1067 ind.).

A survey of soil fauna in Poland revealed 30 cases of centipedes carrying mites of the sub-order Uropodina. The 155 phoretic deutonymphs collected belonged to two species of Uropodina-Oodinychus ovalis (C.L. Koch, 1839) and Uroobovella pulchella (Berlese, 1904). These mites displayed a high degree of selectivity in their choice of carrier. The only species of centipede transporting mites was Lithobius forficatus (Linnaeus, 1758), despite the presence of 30 other species in the same habitats. It is possible that the large size and relatively fast speed of movement of this centipede make it a very good mite carrier. The majority of the mites were located on the sides of the centipedes, on segments near the anterior end. The high selectivity in the choice of carrier as well as the point of attachment suggests adaptation by the mites for phoresy by L. forficatus. 699 * Systematic status correct according to Checklist of Animals of Poland (Wi niewski, 1997).

Underground nests of Talpa europaea, known as the common mole, are very specific microhabitats, which are also quite often inhabited by various groups of arthropods. Mites from the suborder Uropodina (Acari: Mesostigmata) are only one of them. One could expect that mole nests that are closely located are inhabited by communities of arthropods with similar species composition and structure. However, results of empirical studies clearly show that even nests which are close to each other can be different both in terms of the species composition and abundance of Uropodina communities. So far, little is known about the factors that can cause these differences. The major aim of this study was to identify factors determining species composition, abundance, and community structure of Uropodina communities in mole nests. The study is based on material collected during a long-term investigation conducted in western parts of Poland. The results indicate that the two most important factors influencing species composition and abundance of Uropodina communities in mole nests are nest-building material and depth at which nests are located. Composition of Uropodina communities in nests of moles was also compared with that of other microhabitats (e.g. rotten wood, forest litter, soil) based on data from 4421 samples collected in Poland. Communities of this habitat prove most similar to these of open areas, especially meadows, as well as some forest types.

Bird and mammal nests provide microhabitats that support a range of other species, including invertebrates. However, the variation between communities of nest-dwelling invertebrates in different nests is poorly understood. The major aim of this study was to analyze the assemblage structure of mites from the suborder Uropodina (Acari: Mesostigmata) and from superfamily Crotonioidea (Acari: Oribatida) inhabiting nests of the wood warbler, Phylloscopus sibilatrix (Aves: Passeriformes), located on a forest floor in Białowieża Forest, in eastern Poland. We also assessed the correlation between the nest material used by the birds with the assemblage structure of Uropodina mites, and compared the results with published studies of the nests of other birds and a mammal (common mole, Talpa europaea), and also with communities of mites inhabiting the soil. The field research was conducted in the strict nature reserve of the Białowieża National Park, a near-primeval European temperate forest. In 2019, immediately after the breeding period, 69 wood warbler nests and 439 soil samples were collected. Analyses revealed assemblages of Uropodina mites inhabiting the nests that consisted of 14 species, mostly common soil species. Only five species of oribatid mites from superfamily Crotonioidea were present in the nest material. Analyzed nests had a high percentage of tree leaves and grass blades, whereas moss was the least frequent component of the nest material. The Uropodina mites were more abundant in the nests that had greater amounts of grass blades, but similar relationships were insignificant for the nests with varying amounts of tree leaves or moss. The assemblages of Uropodina mites inhabiting wood warbler nests were very similar to those found in soil and nests of the common mole, but they lacked typical nest-dwelling species of Uropodina (i.e., specialized nidicoles).

The study presented in the current article was carried out in two selected natural forest reserves in Poland, i.e. Jakubowo and Las Grądowy near Mogilnica in western Wielkopolska (Poland). The material for the analysis contains quantitative soil samples collected in the period 1978-1983 and more recent material from 2005, 2006 and 2011-2013. The major aim of the study was to establish the changes in species composition, frequency and abundance of Uropodina (Acari: Mesostigmata) mite communities in six plots in Jakubowo and Las Grądowy over a long-term period. The results of the analysis clearly show that the core of the examined mite communities consists of the same eurytopic species, whereas the occurrence of rare species with narrower ecological tolerances was probably to a large extent determined by the different microhabitat conditions in each of the examined areas. The most disturbing phenomenon observed during the research period, which lasted for over 36 years, is a considerable decrease in the abundance of Uropodina in ground litter and soil of the two reserves. The changes that have already occurred in the examined mite communities were associated with natural succession in the flora and anthropogenic disturbances in the environment.