Arthropods on oak branches in SW Finland, collected by a new trap type

Arthropods moving on large horizontal branches of old oaks (Quercus robur L.) in seven oak woodlands, SW Finland, were studied using a new trap type. The most abundant groups included Formicidae (Hym.), Oribatida (Acari), Thysanoptera, Nematocera (Dipt.), Collembola, Auchenorrhyncha (Hom.), Coleoptera, Araneae, Psocoptera and Hemiptera. The last three groups showed the least intersite variation in numbers of individuals. About 120 abundant, rare and other interesting species of Diplopoda (4 species mentioned), Chilopoda (2), Araneae (19), Opiliones (4), Pseudoscorpionida (1), Oribatida (9), Psocoptera (9), Blattodea (1), Neuroptera (1), Homoptera (10), Heteroptera (13), Coleoptera (25), Lepidoptera (14) and Formicidae (6) are listed, and the new trap is described.