Disclosed is a harmful arthropod control composition comprising, as an active ingredient, a fused heterocyclic compound represented by formula (1) [wherein A1 and A2 independently represent a nitrogen atom or the like R1 and R4 independently represent a halogen atom or the like R2 and R3 independently represent a halogen atom or the like R5 and R6 independently represent a linear C1-C6 hydrocarbon group which may be substituted, or the like (provided that both R5 and R6 cannot represent a hydrogen atom simultaneously) and n represents 0 or 1]. The harmful arthropod control composition has an excellent efficacy to control harmful arthropods.