ARTHROPODS ON OAK BRANCHES IN SW FINLAND, COLLECTED BY A NEW TRAP TYPE

Arthropods moving on large horizontal branches of old oaks (Quercus ro bur L.) in seven oak woodlands, SW Finland, were studied using a new t rap type. The most abundant groups included Formicidae (Hym.), Oribati da (Acari), Thysanoptera, Nematocera (Dipt.), Collembola, Auchenorrhyn cha (Hem.), Coleoptera, Araneae, Psocoptera and Hemiptera. The last th ree groups showed the least intersite variation in numbers of individu als. About 120 abundant, rare and other interesting species of Diplopo da (4 species mentioned), Chilopoda (2), Araneae (19), Opiliones (4), Pseudoscorpionida (1), Oribatida (9), Psocoptera (9), Blattodea (1), N europtera (1), Homoptera (10), Heteroptera (13), Coleoptera (25), Lepi doptera (14) and Formicidae (6) are listed, and the new trap is descri bed.