The Opilionida (Arachnida) of the Netherlands

INTRODUCTION Until now very little has been published on the harvestmen of The Netherlands. The earliest paper known to me is by Goedaert (1669), who mentions Phalangium opilio from The Netherlands and gives the following "biological" information: "The animals originate from mush-rooms; they eat salpetre; catch flies with their many-jointed tarsi; at night they play, because there is nothing to prey on". For a long time this was the only "knowledge" concerning Dutch Opilionida, except that according to Houttuyn (1769), Bennet and Van Olivier (1825), Van der Hoeven (1828, 1859), Snellen van Vollenhoven (1859), and Rombouts (1875), the above-mentioned species occurs throughout The Netherlands. An outstanding anatomical study of the sexual organs of a number of species, by De Graaf, appeared in 1882. In "Les Arachnides de Belgique" the Belgian naturalist Becker (1896) records the presence of Nemastoma lugubre 2), Phalangium opilio, and Platybunus triangularis from localities throughout The Netherlands, and Mitopus morio and Odiellus spinosus from Maastricht. The first important publication on distribution and biology of Dutch harvestmen, is by Loman (1900). He mentions the following species: Phalangium opilio, Opilio parietinus, Leiobunum rotundum, Mitopus morio (common from North to South); Oligolophus tridens, Odiellus spinosus, Platybunus triangularis (on sandy soil, in woods, and in heaths); Nemastoma lugubre, Nemastoma quadripunctatum (in South Limburg). Oudemans (1916) and Arnoud (1955) briefly recorded the presence of Trogulus tricarinatus in Limburg. Van der Drift (1950) listed a number of species collected during his investigation of a beech forest, whilst Van der Hammen (1947, 1950) mentions Mitostoma chrysomelas