The present invention provides a composition for use as a harmful organism control agent comprising as an active ingredient one or more of compounds represented by formula (I) or salts thereof and an agriculturally or zootechnically acceptable carrier.wherein Het represents pyridyl X represents an oxygen atom R1, R2, R3, R7, R10a, R10b, R11, and R12 represent a hydrogen atom R4, R5, and R6 represent a hydrogen atom, hydroxyl, optionally substituted C1-18 alkylcarbonyloxy, optionally substituted C1-18 alkylsulfonyloxy, optionally substituted arylcarbonyloxy, C1-6 alkyloxy-C1-6 alkyloxy, C1-6 alkyloxy-C1-6 alkyloxy-C1-6 alkyloxy R8 represents a hydrogen atom and R13a, R13b, and R13c represent methyl.
