Habitat use patterns by ground beetles (Coleoptera : Carabidae) of northeastern Iowa

Ground beetle assemblages were monitored in six different habitats (tallgrass prairie, oats, corn, soybean, old-field, woods) at four sites in northeastern Iowa from 1994 to 1998. The objective of this study was to quantify the influence of habitat type on the activity and distribution of ground beetles. Over five years, 13,654 ground beetles representing 107 different species were captured. Of these, 14 species represented 85 % of the captured beetles. Based on habitat use, we categorized 24 as generalist species, 14 as agricultural species, 12 as grassland species, 39 as prairie specialists, and 19 as woodland species. Tallgrass prairie hosted a significantly more (P < 0.05) diverse assemblage of ground beetles than was found in the other habitats. Prairie also had a higher percentage of habitat specialists in its assemblage than did the less stable agricultural habitats which were dominated by generalists. NMS ordination and indicator species analysis revealed distinct ground beetle assemblages and identified indicator species in the various habitats, allowing species assemblages to be used as habitat indicators.