To provide a novel imino derivative capable of being an insecticide compound which is excellent in characteristics such as sustained effects and a broad spectrum.An imino derivative represented by Formula (A) shown below:wherein "Ar" represents a heterocyclic group which may have a substituent on the ring, "X" represents a sulfur atom or CH2, NR "R" represents a hydrogen atom or an alkyl group"Ya" is selected from "C(=S)NR1R2", "C(=S)SR3", "C(=O)SR4", "C(=S)OR4", "SO2Zα", and "OZp" and, each of "R1" to "R4", "Zα", and "Zp" represents a hydrogen atom or a certain substituentis provided.