Short and long-term impacts of using/removing pheromone mating disruption on codling moth (Cydia pomonella) and Oriental fruit moth (Grapholita molesta) populations

An area-wide mating disruption (AWMD) project for the management of codling moth (CM) and oriental fruit moth (OFM) was conducted from 2006-2008 in Pennsylvania. A number of growers continued to use AWMD in 2009 and 2010, while another set of growers decided to discontinue AWMD after three years. The primary objectives of the study were: 1) to follow CM/OFM populations in orchards that either used MD for five consecutive years or removed MD after three years of use and returned to insecticide use only, 2) to determine if growers who continue to use MD for consecutive years can further reduce insecticide usage, 3) to observe how rapidly CM/OFM adults reinvade orchards that no longer use MD, and 4) to evaluate what are the short and long-term consequences of discontinuing MD after three years of use. The initial AWMD project was conducted in 115 apple and peach blocks while the latter project was conducted in selected 19 apple blocks that continued to use AWMD for two additional years and seven apple blocks that removed MD after three years of use. Seasonal captures of CM and OFM adults remained low in all MD treated blocks while orchards that relied upon just insecticides in 2009-2010, CM/OFM populations rapidly started to increase in size, especially late in the season following the stoppage of MD use during the first year – 2009. Fruit injury in all MD treated orchards continued to remain low, while it increased in orchards receiving just insecticides.