An insect pest control product applicable to a water-based insecticidal composition with stable performance over a long time, which comprises a thermal vaporization/diffusion absorbent wick for vaporizing and diffusing a water-based insecticidal composition containing a pyrethroid insecticidal component having a vapor pressure of 2×10−；4 to 1×10−；2 mmHg at 30° C., a glycol ether compound having a boiling point of 150-300° C., and water. The wick has a water/oil-based liquid absorption ratio (V1/V2) within the range of 0.55-1.0, calculated from a speed (V1) at which a water-based liquid formulation rises through the wick, and a speed (V2) at which an oil-based liquid formulation rises through the wick, the water-based liquid formulation contains 40 mass % of diethylene glycol monobutyl ether, and the oil-based liquid formulation is a fluid paraffin having 14 carbon atoms.
