Abstract: 【Objective】In this paper the resistance risk of Spodoptera exigua to tebufenozide and the biological characteristics of Spodoptera exigua treated with tebufenozide were studied.【Method】Using dipping method, selections for resistant population of spodoptera exigua to tebufenozide were carried out from laboratory strain by treating alternative generation’s 3rd-instar larvae at LC50 dose and treating every generation’s larvae with LC10 dose. The biological characters of each generation were determined. Dipping exposure of 3rd-instar larvae and egg mass of Spodoptera exigua with tebufenozide under different dose, the effects on biology characters in current generation and followed generation was also studied.【Result】Treated alternative generation’s larvae with LC50 dose, Spodoptera exigua had no loss in susceptibility to tebufenozide from F1, F3, F5, F7 ,F9 to F11. But as the selection procedure, the pupation rate, average pupa weight and eggs per female of corresponding followed generation were decreased. Another selection experiment of successive treating every generation’s larvae with LC10 dose of tebufenozide to F19 only obtained 3.52-fold resistance ratio to the initial laboratory strain of spodoptera exigua. The pupation rate, average pupa weight, eclosion rate, adult life and eggs per female had no significant changes in each generation. Dipping exposure of 3rd-instar larvae to tebufenozide solutions of 5-40µg•ml-1, the survival rate of larvae was decreased after three days, and the larval period time, pupation rate and the mean pupa weights were significantly shorter or lower than those of control larvae as the dose increasing. But the eclosion and female/male rate

Key words: Spodoptera exigua, tebufenozide, resistance selection, biological parameters, domino effect