Numerous chemicals were evaluated for control of the brown mite (Bryobia, arborea Morgan and Anderson), the two-spotted spider mite ( Tetranychus telarius (L)), and the McDaniel mite ( T. mcdanieli McGregor) near The Dalles, Oregon during 1955-1959. The entire testing program was conducted in the field using peach ( Prunus persica) and sour cherry ( P. cerasus ) as the test trees. The materials were applied alone, either as sprays or dusts. Trithion® ( S(p -chlorophenylthio)methyl) O,O -diethyl phosphorodithioate) wettable powder and emulsion (flowable), Kelthane® (1,1-bis( p -chlorophenyl)-2,2,2-trichloroethanol) wettable powder, and Tedion® (2,4,4',5-tetrachlorodiphenyl sulfone, 80% technical) wettable powder provided excellent control of all three mite species. Aramite® (2-( p-tert -butylphenoxy)-1- methylethyl 2-chloroethyl sulfite) wettable powder controlled T. telarius and T. mcdanieli but not B. arborea . Ethion wettable powder was also found to control these two web-spinning species. Diazinon® ( O,O -diethyl O -(2-isopropyl-4-methyl-6-pyrimidinyl) in phosphorothioate), parathion, and malathion wettable powders provided limited and short term control. Guthion® ( O,O- dimethyl S- (4-oxo-1,2,3-benzotriazin-3 (4H)-ylmethyl) phosphorodithioate) wettable powder was inconclusive. Sulphellone® ( p -chlorophenyl phenyl sulfone), ovex, and chlorbenside as wettable powders were all ineffective in controlling the web-spinning group. Three per cent Tedion dust provided sufficient control on all three species, but must be applied on small populations for maximum results. Three per cent Kelthane dust controlled the brown mite, but not the two-spotted spider mite or the McDaniel mite. Aramite (3%), Tedion (2%), or sulphur (73% or 84%) dust did not control any of the three species.