A substituted alkenylbenzene compound of formula (4): wherein X1 is a halogen atom, —SF5, C1-C6haloalkyl, hydroxy C1-C6haloalkyl, C1-C6alkoxy C1-C6haloalkyl, C3-C8halocycloalkyl, C1-C6haloalkoxy, C1-C3haloalkoxy C1-C3haloalkoxy, C1-C6haloalkylthio, C1-C6haloalkylsulfinyl or C1-C6haloalkylsulfonyl; X3 is a hydrogen, halogen, cyano, nitro, C1-C6alkyl, C1-C6haloalkyl, C1-C6alkoxy or C1-C6alkylthio; X4 is a hydrogen, halogen, cyano, C1-C4alkyl, C1-C4alkoxy or C1-C4haloalkoxy; R3 is —C(R3a)(R3b)R3c, where R3a and R3b are a halogen, or R3a and R3b together form a 3- to 6-membered ring together with the carbon bonding them by forming a C2-C5haloalkylene chain, and R3c is a hydrogen, halogen, C1-C5alkyl, C1-C5haloalkyl, C1-C4haloalkoxy or C1-C4haloalkylthio, with a proviso that where X1 is a fluorine, chlorine or trifluoromethyl, and X2 and X3 are hydrogen, where X1 and X2 are fluorine and X3 is a hydrogen, or where X1 and X2 are trifluoromethyl and X3 is a hydrogen, R3c is a hydrogen, chlorine, bromine, iodine, C1-C5alkyl, C1-C5haloalkyl, C1-C4haloalkoxy or C1-C4haloalkylthio.