The present invention provides an oil-based pesticidal suspension comprising (1) flonicamid or its salt, (2) an organic silicone type surfactant and (3) at least one oil-based diluting agent selected from the group consisting of a vegetable oil and its alkylated oil, and a method for controlling pests, which comprises applying the oil-based pesticidal suspension to the pests or to a place where they grow.本發明係提供解除調製散布液時，來自有機聚矽氧烷系界面活性劑之起泡，並且以少量農藥而顯示優異的殺蟲活性之油性懸浮狀有害生物防除劑組成物。本發明可提供含有(1)氟尼胺(Flonicamid)或其鹽、(2)有機聚矽氧烷系界面活性劑及(3)選自植物油及此等之烷基化油所成群中之至少1種油性稀釋劑為特徵之油性懸浮狀有害生物防除劑組成物，以及施用該有害生物防除劑組成物於有害生物或其生育地點而成之防除有害生物之方法。
