Codling moth is the key pest of apples in Washington, with a long history of intensive pesticide management. As an internal, fruit-feeding pest, the economic injury level is very low, elevating grower’s response to pressure from this pest. The history of insecticide use begins with the arsenicals in the late 1800s, until resistance, human health and environmental issues made them unusable. They were succeeding by DDT immediately after WWII, which initially provided excellent control (although with a suite of secondary pest flareups). However, resistance to DDT developed after a few decades, and organophosphate insecticides, especially azinphosmethyl, replaced it. The withdrawal of azinphosmethyl in 2012 was followed by an unprecedented diversity of active ingredients, which allowed (perhaps for the first time) a true insecticide rotational schedule. The challenge today is to promote continuing susceptibility in our current arsenal through the use of alternative tactics and technologies. Biological control has had only moderate success, largely due to the low economic injury level. Mating disruption, registered in 1990, was quickly and widely implemented, and has become the foundation of our current codling moth control program. More recently, sterile insect release (SIR) became available to Washington growers on a limited scale, and its use is expanding rapidly, especially in organic production. While the origins of SIR are from the 1950s, this ‘new’ technology for Washington is being investigated as a new tool in the codling moth toolbox.
