The disclosure relates to a benzyloxypyrimidine derivative represented by general formula (I) or salts thereof an agricultural/horticultural insecticide comprising said compound as the active ingredient and a method for using the same. In general formula (I): R1 represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, a haloalkyl group, a haloalkenyl group, a haloalkynyl group, an alkoxyalkyl group, etc. R2 or R3 represents a hydrogen atom, an alkyl group, etc. X represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, a haloalkyl group, a haloalkenyl group, a haloalkynyl group, a trialkylsilyl group, etc. A represents an oxygen atom, etc. and m represents an integer of 0-5, these variables are further defined in the specification. Agrohorticultural insecticide containing these benzyloxypyrimidine derivatives as active ingredients are particularly suitable for controlling ectoparasites.
