PURPOSE: To obtain the subject controlling agent, consisting essentially of a pyrethrin-based insecticide and a specific compound and capable of sustaining excellent termite killing effects with high safety without emitting any unpleasant smell and causing decomposition with heat, water, light, etc., and environmental pollution due to slight decomposability.

CONSTITUTION: A controlling agent consisting essentially of a pyrethrin-based insecticide, e.g. permethrin, cyfluthrin or cypermethrin, and a methylenedioxy compound known as an agricultural chemical insecticide, e.g. piperonyl butoxide. The blending ratio thereof is 0.02 to 5 pts.wt. former based on 100 pts.wt. latter. The contents of the abovementioned essential ingredients are 0.01 to 70 pts.wt. aforementioned pyrethrin-based insecticide and 0.05 to 50 pts.wt. methylenedioxy compound in 100 pts.wt. formulation. The abovementioned essential ingredients are dissolved in an organic solvent alone or in a mixture of two or more kinds thereof and formulated in the form of an emulsion, oil, granule, dust, etc., and used for woody materials or soil by application, spraying with a spray, mixing, etc.