Winteraktivität epigäischer Aranei und Carabidae des Innsbrucker Mittelgebirges (900 m NN, Tirol, Österreich)

Abstract

Activity of surface dwelling arthropods in montane habitats was studied near Innsbruck by pitfall traps mainly in the period 23. 11.–26.2. 1979. Adult Carabidae were almost inactive. Among spiders, adult Erigonidae, Linyphiidae,Pachygnatha (Tetragnathidae) were dominating. 5 winter active species showed their peaks of activity outside the period of true winter, in late autumn and in early spring, they thus behaved like stenochronous species reproducing in autumn and diplochronous species resp. This behaviour can be seen also in other mesic sites and in other species (genera:Centromerita, Centromerus, Leptyphantes; Scotinotylus, Walckenaera). In the northern Alps, at this elevation true winter activity is shown by species of “xeric” slopes only (Centromerus incilium, Leptyphantes pinicola, and others). This is in accordance with an observation showing spider activity in high alpine regions negligible in winter.