A survey in 5 geographic blocks of North Carolina indicated that an average of 24% of the brood ofDendroctonus frontalisZimmerman had been parasitized and preyed upon by zoological agents. The effeet of these agents was assessed and compared during 3 years, in 3 attack stages on the tree, in 3 tree species, and in 3 sections of the tree. The more effective predatory agents were woodpeckers, the cleridThanasimus dubius(F.), and an anthocorid,Scoloposcelis mississippensisDrake&Harris. Of several parasites,Roptrocerus xylophagorumRatzeburg andColeoides pissodesAshmead contributed most to total mortality.