Because corn rootworms are beetles, a potential exists for adverse effects of rootworm resistant corn on nontarget beneficial beetles. In particular, a major risk factor might be imposed on carabids because they are ubiquitous in the agricultural landscape. The global hypothesis of these studies was that carabid beetle communities would not be affected adversely by introduction of Bt corn into cropping systems. The study site consisted of about 160 acres planted to soybean. Within the soybean, three corn treatments were planted in 2-ha plots: Mon863 (Btn), an isoline (non-Btn) treated with Force (1 lb a.i./acre), and an untreated isoline. Four pitfall traps per plot were placed in the approximate center of the plot quadrats. Additional pitfall traps were placed in soybean alleyways and plot borders to serve as reference points for overall ground beetle activity. The position of each pitfall trap was georeferenced to allow mapping of ground beetle activity levels. Ground beetles were collected weekly and identified to species. There were no significant differences in numbers of ground beetle trapped among treatments, suggesting that presence of MON863 did not affect carabid beetle abundance. Crop-specific spatial variation was apparent for some species. Pending further analysis, there appear to have been no adverse effects on carabid beetles associated with the MON863 plots.