The effects of the bait spray GF-120 against the western cherry fruit fly were determined in laboratory and field studies. Flies were attracted to a 1:1.5 GF-120: water dilution in the laboratory when starved for 24 hours, but were not highly attracted when not starved or when exposed to lower dilutions (1:20 and 1:160). Flies also fed on droplets of the high dilution more so than to drolets of lower dilutions. Cherries dipped in high dilutions of GF-120 and exposed to gravid females in the laboratory generally were free of infestation. In the field, GF-120 at high dilutions but not low dilutrions were effective in controlling cherry fruit flies.