Broadleaf forests are critical habitats for biodiversity and this biodiversity is in turn essential for their proper functioning. Mites (Acari) are a numerous and functionally essential component of these forests. We report the diversity of two important groups, Oribatida and Mesostigmata, in a broadleaf forest in Eastern Norway which is considered to be a biodiversity hotspot. Eighteen samples, each 500 cm³, were collected from diverse microhabitats (moss on ground, lichens on tree twigs lying on ground, moss on tree trunks at ground level, moss on tree trunks 1.5 m above ground, moss on decaying stump, moss on decaying log, and decaying wood from trees) from which 10,843 specimens and 95 species from 32 families of Oribatida, and 655 specimens of 34 species from 14 families of Mesostigmata were found. Only 30% of the species were previously recorded in broadleaf forests in Western Norway. Oribatid communities on decaying stump and in lichens were distinct from the other communities, while mesostigmatid communities on tree trunks (both at ground level and 1.5 m above ground) and in lichens differed most from other communities. Over 30% of the species were found in only a single microhabitat. Twenty-three species and the genus Zerconopsis are reported from Norway for the first time. Six records are also new to Fennoscandia, including (Oribatida) Coronoquadroppia monstruosa, Eueremaeus valkanovi, Ramusella furcata, and (Mesostigmata) Dendrolaelaps rectus, D. multidentatus, and D. tenuipilus. In addition, several rare species were detected, e.g., Achipteria magna, Oribotritia berlesei, and Subiasella quadrimaculata, and two were found in their northernmost locality (O. berlesei, E. valkanovi). These results confirm the unique character and high conservation value of the studied forest in Norway, Fennoscandia and at a European scale.

In Macrocheles glaber (Müller), oviposition can involve either oviparity or egg production followed by immediate hatching of the larva, a process that may be called ovoviviparity. We observed three phases in the process of ovoviviparity: preoviposition behaviour, oviposition followed by holding the egg under the gnathosoma and hatching of the larva assisted by the female. Two factors appear to favour the occurrence of ovoviviparity in this species: poor feeding and poor substrate quality. We witnessed egg cannibalism four times in two of the four females that we observed. We discuss the consequences of variable oviposition strategy, parental care and egg cannibalism in M. glaber in the context of maximization of reproductive success.

Zercon utemisovi sp. n., (Parasitiformes: Mesostigmata: Zerconidae) from Kazakhstan is described and illustrated based on adults of both sexes. The new species is most similar to Zercon karadaghiensis, which we compare to our new species, and we note that mites previously identified as Z. karadaghiensis may include more than one species. http://www.zoobank.org/urn:lsid:zoobank.org:pub:410D246F-90BF-4FE6-81C7-4CAD64A9BAD3