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).