Abstract Sprays were applied dilute to run off with a truck-mounted, high-pressure, handgun sprayer (450 psi) in two different orchards. Plots were set up in ‘McIntosh’ apple trees, ca. 2 m high, at the Trickier farm and in ‘Delicious’ trees, ca. 3 m high, at the Furber orchard. Treatments were arranged in a RCB design, replicated four times. The sprays at the pink bud stage of CM-006 and Morestan 25WP, which was used as a standard acaricide comparison treatment at this growth stage, were applied on 12 May at the Trickier farm and 15 May at the Furber orchard. The petal fall treatment of CM-006 and Omite 30W, which was used as a standard acaricide comparison treatment, were applied on 1 Jun at the Trickier farm and on 2 Jun at the Furber orchard. Twenty-five mature leaves from either fruit clusters or terminals were randomly selected from the single tree in each plot on 16 Jun, 27 Jun, 11 Jul, 19 Jul, and 2 Aug. Leaves were brought into the laboratory immediately after being sampled and ERM and T. pyri were removed from the leaves of these samples with a Henderson-McBumie mite brushing machine. Data shown in the tables was transformed Log N(X + 1) prior to analysis with a Fisher’s Protected LSD test (P<0.05).