Three new moult-inhibiting insect growth regulators, BAY SIR 8514 (N-[[[4-(trifluoromethoxy)phenyl] amino] carbonyl]-2-chlorobenzamide), LY-127603 (N-[[[5-(4-bromophenyl)-6-methylpyrazinyl] amino] carbonyl]-2-chlorbenzamide), and LY-131215(2,6-dimethoxy-N-[5-[4-(pentafluorethoxy)phenyl]-1,3,4-thiadiazol-2-yl] benzamide) were tested in the laboratory and in the greenhouse against Choristoneura fumiferana (Clemens). In addition, BAY SIR 8514 was tested m the field. The EC50 ranged from 0.05 to 0.14 ppm in diet tests and the compounds were stable to autoclaving and UV-exposure from a sun lamp. Greenhouse tests indicated that the equivalent of 35 g in 4.7 liters/ha gave 95% control for BAY SIR 8514, 98% for 127063 and 83% for 131215. Experimental aerial application of BAY SIR 8514 showed that at 210 g/ha or more, the level of control achieved was similar to that of the carbamate pesticide, aminocarb at 70 or 70 + 70 g/ha.