The effectiveness of biocontrol of Panonychus citri with Stethorus punctillum in citrus orchards can be enhanced in two ways. One is by double releases to raise the number of S. punctillum, with the first release in mid May and the second in mid September. The other is by planting alternative host plants in a citrus orchard to provide a refuge for S. punctillum and enable it to survive the food crisis in autumn. The main kinds of alternative host plants and the associated species of leaf mites were investigated around Guiyang City. A plan to design a system of alternative host plants of S. punctillum in a multiple-species citrus orchard system is put forward.