PROBLEM TO BE SOLVED: To provide a combination of a bactericide or an insecticide having a synergistic effect exhibiting a wide range of activity to avoid development of a resistant strain while the dose of a chemical product sprayed in the environment is decreased as possible and the treatment cost is reduced.SOLUTION: A composition comprises a pyridylethylbenzamide derivative (a) represented by the formula (I) and an insecticidal compound (b) such as fipronyl, clothianidin and pymetrozine in a weight ratio of 1/1000 to 1000/1 of (a)/(b). [In the formula, p represents an integer of 1 to 4, q represents an integer of 1 to 5, X each independently represents a halogen atom, an alkyl group, a haloalkyl group and the like, and Y each independently represents a halogen atom, an alkyl group, a haloalkyl group and the like.]【課題】環境中に散布される化学製品の薬量をできる限り少なくし且つ処理コストを低減しながら、抵抗性株の発達を避けるための、広い範囲の活性を示し相乗効果を有する殺菌剤又は殺虫剤の組み合わせを提供する。【解決手段】下式（Ｉ）で表されるピリジルエチルベンズアミド誘導体（ａ）及び、フィプロニル、クロチアニジン、ピメトロジン等の殺虫性化合物（ｂ）を、１／１０００～１０００／１の（ａ）／（ｂ）の重量比で含む組成物。［式中、ｐは１～４の整数を表し、ｑは１～５の整数を表し、Ｘは、それぞれ独立して、ハロゲン原子、アルキル基、ハロアロキル基等を表し、Ｙは、それぞれ独立して、ハロゲン原子、アルキル基、ハロアルキル基等を表す。］【選択図】なし
