When broad-spectrum pesticides are used for management of primary pests, such as codling moth, secondary or minor pests can become problematic because natural controls are reduced or eliminated. Flint and van den Bosch (1981) said that the post-World War II pesticide revolution “ushered in a whole new spectrum of previously unknown pests.” Croft (1982) noted that several apple arthropod pests, including San Jose scale, oystershell scale, European red mite, two-spotted spider mite, apple rust mite, rosy apple aphid, wooly apple aphid, white apple leafhopper, and red-banded leafroller had reached seriously problematic levels because their natural enemies had been killed or […]