A bioeconomic model is developed to analyze the optimal control management strategies for an introduced herbivore in a two-compartment ecosystem. This paper analyzes cost-effective control strategies that decrease the spillover effects of the herbivore on endangered plant species, thereby reducing extinction pressure and increasing benefits. The optimal level of control is presented in different circumstances. The level of optimal control is high if the herbivore has a relatively low attack rate on the target species, the nontarget host has a high biodiversity value, or the costs of controlling the herbivore are low.