Population dynamics of phytophagous and phytoseiid mites in a newly planted apple orchard were investigated for the consecutive 5 years just after the stop of insecticide applications, to verify the effect of the phytoseiids on the dominance and density of phytophagous mite species. Phytoseiid mites were typically most abundant in autumn from 2005 to 2008, except in 2009 when there were two marked peaks. Although 10 phytoseiid mite species were collected over the five-year study period, species abundance and composition changed gradually over time. The phytophagous mites were most abundant in the autumn of 2005, but the timing of peak occurrence and density changed as the study progressed. Changes in the abundance and species composition of the phytoseiid mite communities, Tetranychus urticae abundance was not suppressed by the phytoseiid mites. Although Panonychus ulmi was suppressed to insecticide application, P. ulmi may affect T. urticae abundance under a no-insecticide regime. Finally, T. urticae disappeared and P. ulmi and Aculus schlechtendali decreased in abundance. Although not marked, Typhlodromus vulgaris played a key role in affecting the stability of mite communities in apple orchards when no insecticides were applied.

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Hypoaspis (Gaeolaelaps) praesternalis Willmann, 1949, was collected from the soil of spinach-cultivated fields in greenhouses located in Hokkaido, northern Japan. This is the first record of H. (G.) praesternalis from Japan. Intraspecific variation was apparent in the length of the spermatodactyl of the male chelicera.

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A 2008-2010 survey of mite fauna in spinach greenhouses found 24 females of a phytoseiid mite species of the genus Neoseiulus in soil and spinach sprouts. This species was identified as N. harrowi (Collyer), described originally in New Zealand and Australia and new to Japan. This species is the fourth member of the N. barkeri species group among Japanese phytoseiid fauna, and was given the Japanese name ‘hourensou-kaburidani’. The species was observed associating with a spinach-damaging mite, Tyrophagus similis Volgin, in the greenhouse. The present paper describes the habitat of N. harrowi and presents a simple method of distinguishing it from the three other domestic species of the N. barkeri group (N. barkeri Hughes, N. makuwa (Ehara), N. womersleyi (Schicha)).

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A new oribatid mite of the family Oribotritiidae, Indotritia nunomurai sp. nov., is described from litter and soil layer of Cryptomeria japonica forests in Toyama Prefecture, Central Japan. The new species is readily distinguishable from the congeners by the spindle-shaped sensilli with elongated tip.

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