Ground beetle (Coleoptera: Carabidae) assemblages in the Conservation Reserve Program crop rotation systems in interior Alaska

To improve knowledge of ground beetle communities and the influence of habitat succession on these communities in Alaska, adult ground beetle (Coleoptera: Carabidae) activity and diversity was documented on Conservation Research Program (CRP) agricultural lands in Delta Junction, Alaska (64oN, 145oW). Twenty species, based on a total sample of 6,116 specimens, were collected during 2006 and 2007 from plots that were in the CRP for 9 years (young-field plots) and 19 years (old-field plots). Two species, Cymindis cribricollis Dejean and Amara obesa Say, are reported for the first time for Alaska. Species richness of carabids for our study plots was estimated using the Chao 1 and Chao 2 estimators to be 22 and 28 species, respectively.  Ninety-four percent of the specimens belonged to five species Pterostichus adstrictus Eschscholtz (42.9%), Agonum cupreum Dejean (17.9%), Calathus ingratus Dejean (15%), Amara obesa (11.1%), and Dicheirotrichus cognatus (Gyllenhal) (7.1%). Only Ag. cupreum showed significant effects based on plot age. The majority of carabid activity occurred late in the season, from mid September to early October. A comparison of our findings is made with historical data (1943-1956) from the collection of the Matanuska Experiment Station now incorporated into the University of Alaska Museum Insect Collection.