A heterocyclic compound represented by formula (1):wherein A1, A2, R1, R2, R3, R4, n and so on are defined in tha description, has an excellent preventing effect on arthropod pests and is useful for preventing of arthropod pests.本發明係關於一種以式(1)表示之雜環化合物:其中A1、A2、R1、R2、R3、R4、n等係於說明書中定義,該雜環化合物對節足動物害蟲具有優良防治作用且適用於防治節足動物害蟲。