N-(2,6-Dichlorobenzoyl)- and N-(2,6-difluorobenzoyl)-N'-pyrimidinylureas 3b-3n have been synthesized by reaction of the corresponding aminopyrimidine derivatives with 2,6-dichlorobenzoyl isocyanate or 2,6-difluorobenzoyl isocyanate.The insecticial activit