Provided is a heterocyclic compound which exhibits an excellent controlling effect against harmful arthropods. In particular, provided is a heterocyclic compound represented by formula (I), wherein Q denotes a group represented by Q1 or the like, A2 denotes a nitrogen atom or CR4a, A3 denotes a nitrogen atom or CR4b, A4 denotes a nitrogen atom or CR4c, and T denotes a C1-C10 linear hydrocarbon group having one or more halogen atoms, or the like. Also provided is a composition that contains this compound and one or more components selected from the group consisting of group (a), group (b), group (c), group (d) and group (e) as listed in the description.
