A compound represented by the following Formula (I) or a salt thereof, as well as a formulation for controlling harmful organisms, and in particular, an insecticidal formulation, a miticidal formulation, a formulation for controlling ectoparasites or a formulation for controlling or killing endoparasites, which contains at least one compound selected from the compounds of Formula (I) and salts thereof as an active ingredient.wherein, R1 and R2 each independently represent a hydrogen atom, a substituted or unsubstituted C1-6 alkyl group, or the like, with the proviso that when R2 represents a hydrogen atom, R1 represents a substituted or unsubstituted C6-10 aryl group or a substituted or unsubstituted 3- to 6-membered heterocyclyl group； R3 represents a C1-6 alkylthio group or the like； R4 and R5 each independently represent a hydrogen atom, a halogeno group or the like； and Ar represents a substituted or unsubstituted C6-10 aryl group, or a substituted or unsubstituted 5- to 6-membered heteroaryl group.一種由式(I)所表示之化合物或其鹽、以及含有選自由式(I)所表示之化合物及其鹽所組成之群中之至少一種作為有效成分之有害生物防治劑，尤其是殺蟲劑或殺蟎劑、體外寄生蟲防治劑、或者體內寄生蟲防治劑或驅除劑。式(I)中，R1及R2分別獨立地表示氫原子、經取代或未經取代之C1~6烷基等。其中，於R2為氫原子之情形時，R1為經取代或未經取代之C6~10芳基、或者經取代或未經取代之3~6員雜環基。R3表示C1~6烷基硫基等。R4及R5分別獨立地表示氫原子、鹵代基等。Ar表示經取代或未經取代之C6~10芳基、或者經取代或未經取代之5~6員雜芳基。
