Disclosed is an imino derivative which can be used as a pesticidal compound having excellent properties including long-acting efficacy and a broad spectrum. Specifically disclosed is an imino derivative represented by chemical formula (1) [wherein &ldquoAr&rdquo represents a heterocyclic group which may have a substituent on the ring &ldquoX&rdquo represents a sulfur atom, CH2 or NR &ldquoR&rdquo represents a hydrogen atom or an alkyl group &ldquoY&rdquo represents a group selected from COR1, CONR3R4, CONHCOR5 and CO2R9 and &ldquoR1&rdquo, &ldquoR3&rdquo, &ldquoR4&rdquo, &ldquoR5&rdquo and &ldquoR9&rdquo independently represent a hydrogen atom or a specific substituent].
