Alpha diversity of mesostigmatid mites associated with the bark beetle Ips typographus (L.) in Poland

1. The major aim of this study was to establish the role and importance of the spruce bark beetle Ips typographus (L.) in increasing species biodiversity in spruce forests through phoresy of mesostigmatid mites. The study is a close examination of 26 041 specimens of I. typographus, which were carriers of 7210 individuals of mites, classified into 24 species. The most numerous species were Dendrolaelaps quadrisetus, Trichouropoda polytricha, and Urobovella obovata. It is noteworthy that the last two species have not been found so far in other types of microhabitat. Moreover, the analysed material also contained a few extremely rare species such as Amblyseius rademacheri and Uroseius acuminatus. 2. The spruce bark beetle is regarded by forestry experts as one of the most common pest beetles inhabiting spruce forests of Eurasia. Although this species sometimes causes serious economic damage in some regions, it is also one of those organisms which create favourable conditions for many species of fungi and invertebrates; also, it often serves as a carrier for many other organisms. The results of the study show that both presence and abundance of I. typographus determine occurrence of many species, and for this reason forest management evaluations of the function of this beetle in forest ecosystems should also take into account the importance of the species in increasing biodiversity of forests.