A fused heterocyclic compound represented by formula (1) : wherein A 1 represents N or the like, A 2 represents NR 6 or the like, A 3 represents CR 12 or the like, R 1 represents a C1 to C6 chain hydrocarbon group or the like, R 2 and R 4 are the same or different and represent a C1 to C3 alkyl group optionally having one or more halogen atoms or the like, R 3 represents a C1 to C6 chain hydrocarbon group or the like, R 6 represents the same C1 to C6 chain hydrocarbon group or the like, any one set of R 9 and R 10 , R 30 and R 11 , and R 11 and R 12 in R 9 , R 10 , R 11 and R 12 , together with the carbon atoms to which they are bound, forms a ring, and n represents 0, 1 or 2, or an N-oxide thereof has an excellent control effect on pests.
