A noxious arthropod controlling composition comprising a heterocyclic compound represented by the formula (1) [wherein, A1 and A2 represent ═C(R6)—, nitrogen and so on, R1 represents a halogen and so on, R3 and R4 represent optionally substituted C1 to C4 chain hydrocarbon group and so on, R5 represents a hydrogen and so on, n represents 0 or 1] as an active ingredient has an excellent effect for controlling noxious arthropods.
