Douglure, a 4: 1: 1 mixture of frontal in, camphene, and alpha-pinene, respectively, was very effective in inducing mass attacks by the Douglas fir beetle,Dendroctonus pseudotsugaeHopkins, on live Douglas fir,Pseudotsllga menziesii(Mirb.) Franco. Attack densities were lower in baited mass-attacked trees than in naturally attacked trees. However, mass-attacked trees that were adjacent to a baited tree achieved attack densities comparable to naturally attacked trees.Baiting of individual live trees was more efficient in aggregating the pest population within 1 chain of the bait trees than was a pattern of baiting trees in groups of 3. Presalvage baiting with Douglure should maximize the removal of Douglas fir beetle-infested trees.Deadtrapping with Douglure-baited plywood panels coated with Stikem Special® docs not appear to be effective in a pest-management program, probably because of the overwhelming effectiveness of natural pheromone sources.