A compound of the formula: ##STR1## wherein R.sub.1 is a hydrogen atom, a lower alkyl group or a halo(lower)alkyl group, R.sub.2 and R.sub.3 are, the same or different, each a hydrogen atom, a halogen atom, a nitro group, a cyano group or an optionally substituted lower alkyl, lower alkenyl, lower alkynyl, cyclo(lower)alkyl, lower alkoxy, lower alkenyloxy, lower alkynyloxy, cyclo(lower)alkoxy, lower alkylthio, lower alkenylthio, lower alkynylthio, cyclo(lower)alkylthio, di(lower)alkylamino, lower alkylsulfonyl or lower alkylsulfinyl group, or R.sub.2 and R.sub.3 are combined together to form an optionally substituted 5- or 6-membered, saturated or unsaturated ring optionally having not more than two oxygen or sulfur atoms in the ring, R.sub.4 is a halogen atom or a lower alkyl group, R.sub.5 is a hydrogen atom or a lower alkyl group, X is an oxygen atom, a sulfur atom, a methylene group, a sulfonyl group, a sulfinyl group or an imino group and n is an integer of 1 to 4, which is useful as an insecticide and/or an acaricide.