To provide novel pesticides, especially insecticides or acaricides. A condensed heterocyclic compound represented by the formula (1) or its salt, or N-oxide thereof: wherein Q is a structure represented by Q1, Q2 or the like, D substituted with -S(O) n R 1 is a structure represented by D1 or D2, A 1 is N(A 1a ) or the like, A 1a is C 1 -C 6 alkyl or the like, A 4 is a nitrogen atom or C(R 4 ), A 5 is a nitrogen atom or C(R 5 ), R 1 is C 1 -C 6 alkyl or the like, each of R 2 , R 5 and R 6 is independently a hydrogen atom or C 1 -C 6 alkyl, each of R 3 , R 4 , Y1, Y2, Y3 and Y4 is independently a halogen atom, halo (C 1 -C 6 ) alkyl or the like, and n is an integer of 0, 1 or 2.
