The present invention provides a composition for use as a harmful organism control agent comprising as an active 5 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, Rioa, Riob, R11, and R12 represent a 15 hydrogen atom R4, R5r 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-CI_6 alkyloxy-CI_6 alkyloxy R8 represents a hydrogen 20 atom and R13a, R13b, and R13c represent methyl.
