ABUNDANCE, DIVERSITY AND DISPERSAL POWER OF ROVE BEETLES (COLEOPTERA,STAPHYLINIDAE) IN A RASPBERRY PLANTATION AND ADJACENT SITES IN EASTERN CANADA

We used pitfall traps and flight intercept traps in a raspberry planta tion and adjacent sites in eastern Canada, from early May through late October, in 1987, 1988 and 1989. We collected 11,140 Aleocharinae and 16,074 rove beetles of 181 other taxa including 49 Holarctic or immig rant species in North America. Gyrohypnus angustatus Stephens and Tach inus corticinus Grav. were the dominant epigean species in rows of old and young raspberry plantations. These two European species and 15 ot her taxa were captured each year and represented about 98% of the annu al catch (excluding Aleocharinae) in raspberry rows. In spite of this apparent stability, epigean staphylinid assemblages in the raspberry p lantation were variable because of the local population instability of several species. Many of the more common staphylinid species active a t the soil surface in the raspberry plantation flew readily. Only a fe w Nearctic eurytopic species were abundant in this ecosystem disturbed by agricultural practices. We suggest that Nearctic specialist specie s of open sites are collected in smaller numbers in strongly disturbed Canadian agroecosystems, because of their weak migration flights. Oth erwise, many common epigean or flying staphylinid species at a woods-f ield boundary and in an adjacent pine woods were generally Nearctic. W e also observed sexual variation of dispersal power in seven abundant species collected by both methods.