Ground Beetles in Three Western Washington Prairies and Associated Oak Forests

Ground beetle (Coleoptera: Carabidae) diversity, distribution and activity density were investigated from April, 2005 to April, 2006 at three prairies in Thurston County, Washington: Glacial Heritage, Mima Mounds, and Scatter Creek. I collected ground beetles in pitfall traps from six prairie transects and two oak forest transects. I collected a total of 12,464 beetles representing 24 species. Species composition varied among the three different sites. Large numbers of an introduced species, Calathus fuscipes (Goeze), were found in the prairie habitats, comprising 1% to 82% of the carabids in each prairie. Activity‐density peaked from August through October in the prairies and July through September in the forests. Some beetle activity occurred
throughout the winter.