A survey of grassland and montane arthropods collected in the southern Okanagan region of British Columbia.

Abstract

The arthropods of the Osoyoos - Mt. Kobau area (119° 40' W, 49° OS' N) in the southern Okanagan valley of BC were surveyed in the summer of 1991. Mt. Kobau is a high ridge with south-facing slopes covered in grassland and sagebrush from valley bottom to summit. A variety of insect traps and active collecting techniques was used to obtain the greatest possible diversity of arthropod species in the samples. Collections were made in a roughly vertical transect of Mt. Kobau from 300m at Osoyoos to the summit at 1861 m. Eighty-eight samples were sorted to select the greatest number of taxa possible. A total of 5566 specimens was prepared for identification and of this, 5023 were identified to species (or morphospecies) by March, 1994. We collected at least 1101 species, including 12 new distributional records for Canada, 15 new distributions for BC, 30 possible new records for Canada and 14 possible new records for BC, 2 new spccies, and 84 specics considered rare, restricted or potentially endangered. Most of the rare species and records were found at low elevations and are typical of deserts and arid sagebrush grasslands of the Great Basin and Columbia Plateau to the south. Comparison of catches made by different collecting techniques indicates that pantraps catch the most specics and are the most cost effective.

Key words: faunistics; biogeography; grassland; steppe; desert