Provided is an excellent aqueous pest control solution for heating and transpiration.The aqueous pest control solution contains a pyrethroid compound represented by formula (1), an ester compound having a vapor pressure at 25℃ of 1 × 10-10 to 1 × 10-4 mm Hg according to Donovan’s method and having one or more (C4-C12 alkoxy) carbonyl group, a glycol ether and a water.Wherein R1 and R2 are the same or different and represent a hydrogen atom, a methyl group, a trifluoromethyl group or a chlorine atom, R3 represents a hydrogen atom, a methyl group or a methoxymethyl group.]本發明提供一種優異的加熱蒸散用水性害蟲防除液。本發明之水性害蟲防除液係含有式(1)所示之擬除蟲菊酯化合物、根據Donovan法在25℃之蒸氣壓為1×10-10至1×10-4mmHg並且具有1個以上(C4至C12烷氧基)羰基之酯化合物、二醇醚，以及水，[式中，R1以及R2為相同或相異表示氫原子、甲基、三氟甲基或氯原子，R3表示氫原子、甲基或甲氧基甲基]。
