History of IPM in California pears--50 years of pesticide use and the transition to biologically intensive IPM

During the 1960s, the California pear industry, on a per acre basis, was among the heaviest users of pesticides. Each season, multiple sprays of up to 14 active ingredients (chlorinated hydrocarbons, organophosphates and carbamates) were typically applied for control of insects and mites. The cost of control escalated while damage from arthropod pests increased owing to greater pest resistance and more pest resurgence. The pear industry suffered classic symptoms of the 'pesticide treadmill'. By the late 1960s, key pear industry leaders demanded action. Simultaneously, newly emerging concepts of IPM were being developed and funded. With public awareness and environmental activism on the rise in the wake of Rachel Carson's Silent Spring, the stage was set for change. This paper elucidates how pear growers, university researchers and extension agents, environmentalists, government regulators, private consultants, farm chemical suppliers and others contributed to the reduction in insecticide use in California pear orchards. Today, arthropod IPM in pears is characterized as relatively low input, biologically intensive and very successful. For example, in 2008 many pear growers only applied between three and five active ingredients (mainly organically certified) per season for control of arthropods.