The purpose of the present invention is to develop and provide an agricultural and horticultural insecticide that is novel in terms of factors such as the occurrence of pests resistant to existing chemicals and the like because significant damage still occurs due to pests and the like in crop production such as agriculture and horticulture provided are an imidazopyridazine compound represented by general formula (I) {in the formula, A1, A2, A3, or A4 may be the same or different and represent a nitrogen atom or CH group, R1 represents an alkyl group, R2 represents an alkyl group, R3 represents a haloalkyl group, R4 represents a hydrogen atom, Z represents a haloalkyl group or the like, A represents S, SO, SO2, S=N-R5group, or S(O)=N-R5 group, and n represents 1.} or salts thereof, an agricultural and horticultural insecticide having the same as an active ingredient, and a method of use thereof.在農業及園藝等之作物生產中,害蟲等所導致的損害現今仍大,因此本發明係由於對既有藥劑有抵抗性之害蟲的產生等主要因素,而以開發、提供新穎的農園藝用殺蟲劑為課題,並提供以通式(I)所示咪唑嗒化合物或其鹽類、以此為有效成分的農園藝用殺蟲劑以及其使用方法{式中,A1、A2、A3或A4可相同或不同,表示氮原子或CH基,R1表示烷基,R2表示烷基,R3表示鹵烷基,R4表示氫原子,Z表示鹵烷基等,A表示S、SO、SO2、S=N-R5基、或S(O)=N-R5基,n表示1}。
