The Oribatei (Acari) of the Netherlands

INTRODUCTION The study of the Oribatei (moss mites or beetle mites) of the Netherlands was started by Oudemans, who in 1896 published his "List of Dutch Acari, First Part, Oribatei", that was followed in 1900 and 1902 by a first and by a second part of a "New List". After that time Oudemans repeatedly published papers in which Oribatei of the Netherlands were dealt with, although in his later years he paid less attention to this group of Acari. Only a part of the moss mites that Oudemans collected were mentioned by him; a preliminary catalogue of his collection, containing some hitherto unpublished faunistical data on Oribatei, appeared after his death (Buitendijk, 1945). Willmann (1930) published a note on interesting Oribatei in the Oudemans Collection, and among these were some species described after Dutch material. Wasmann (1899) recorded four species of Oribatei from ants' nests ; these were apparently identified by Michael. Geijskes (1950) collected mites on the small isle of Griend; his list contains five species of moss mites. In investigations of the soil fauna of recent years much attention has been paid to the Oribatei ; important papers on this subject were published by Noordam and De Vlieger (1943), and by Van der Drift (1950), who showed that the Oribatei are the predominating group of inhabitants of the litter. This common occurrence, together with the uncertain identity of many of the species recorded up till now, made it desirable to have a critical revision of the Oribatei of the Netherlands. For this reason I started the present study. The above mentioned papers together contain the names of about 110