LAUSR

ABSTRACT The species of the genus Tetranychus Dufour are highly specialized pests that produce significant economic losses in crops. The red spider mite, Tetranychus merganser Boudreaux (Acari: Tetranychidae), is found in the United States, China, Mexico, and Thailand, and feeds on several plant species of economic importance. This study aimed to evaluate the effect of Chamaedorea radicalis Mart ethanol extract at different concentrations (5, 10, 50, 100, 250, 500, and 1000 µg/mL) on T. merganser adult females under laboratory conditions. The different concentrations did not cause mortality in T. merganser; but did have significant effects on female spider mites’ egg-laying, food intake, and demographic parameters. These effects require further study, since they can have considerable implications for natural enemies.