Spider mite outbreaks following the application of insecticides have been associated with changes in mite dispersal behavior. Dispersal responses of twospotted spider mite,Tetranychus urticaeKoch, and Banks grass mite,Oligonychus pratensis(Banks), were studied when mites were exposed to various sublethal concentrations of insecticides on maize under laboratory conditions. Insecticides tested were formulated materials of permethrin and methyl parathion. The study was conducted under direct exposure of mites to pesticides and exposure to their residues. Mites showed greater dispersal behavior when exposed to pesticides directly compared with residual exposure. Spin–down was the predominant mode of dispersal when mites were exposed to insecticides directly, whereas mites that were exposed to the residues dispersed mainly by walk–off. An increase in dispersal of both species of spider mites was observed as concentrations of insecticides increased from LC50to LC50. At LC50, methyl parathion caused greater dispersal of Banks grass mites compared with twospotted spider mites by both direct and indirect exposure. In contrast, at LC50permethrin caused greater dispersal of twospotted spider mites compared with Banks grass mites by both conditions of exposure.