Effect of Fenvalerate on Control of European Red Mite (Acari: Tetranychidae) on Peaches with Acaricides

The effect of fenvalerate on acaricidal control of European red mite, Panonychus ulmi (Koch), on peaches was evaluated. On control trees, two applications of fenvalerate resulted in a 3.3-fold increase in number of mite-days. In addition, the effectiveness of four of six acaricide treatments was reduced by treatment with fenvalerate, beginning ≈50d after treatment for cyhexatin and 88 d after treatment for clofentezine and hexythiazox. Because of late-season increase of mites in the acaricide plots treated with fenvalerate, counts of overwintering eggs increased by a factor of 6-31 times relative to comparable acaricide treatments not over sprayed with fenvalerate.