Mass-trapping doesn't suppress populations of the smaller European elm bark beetle but is useful as a monitor.

P. Dean Smith, Farm Advisor, Inyo-Mono counties, is especially acknowledged for his help. Los Angeles Department of Water and Power assisted with tree sampling, and all traps were placed with the permission of utility companies in Owens Valley. P. Endicott, S.L. Clement, the late R. W. Bushing, and many others assisted in the project. The work was supported by grants from the USDA Forest Service and the State of California.