Mating disruption for control of damage by codling moth in Virginia apple orchards

Abstract

AbstractPolyethylene dispensers (Shin Etsu) containing 172 ml of the sex pheromone, (E,E)‐8–10‐dodecadien‐1‐ol (63%), dodecenol (31%) and tetradecenol (6%), of codling moth (CM), Cydia pomonella (L.), were placed in apple orchards in Virginia. Two blocks of about 2 ha each were treated in 1989, and three in 1990. Dispensers were placed in trees at a density of 1000/ha shortly after apple bloom. Male orientation to pheromone traps was almost totally disrupted (a few males were captured at high population densities). In 1989, the Daleville pheromone‐treated block had 0.9% and 0.8% CM‐injured fruit in the center and edge, respectively; 0% and 39.5% injured fruit were found in the conventional control and abandoned blocks, respectively. The Criglersville orchard (‘organically’ managed, with high CM density) CM harvest injury was 16.0%, 16.5%, 34.5%, and 26.5% in the pheromone‐treated center and edge, organic control and abandoned blocks, respectively. In 1990, the Daleville CM harvest injury was 4.7%, 7.3%, 1.1%, 0.3% and 58%, in the pheromone‐treated center and edge, control center and edge, and abandoned blocks, respectively (possible reasons for the high injury in this block are discussed). Harvest injury in the Fincastle pheromone‐treated and control blocks were 0.7% and 0%, respectively. The Criglersville orchard yielded 17%, 19% and 20% CM‐injured fruit at harvest in the pheromone‐treated, organic control and abandoned blocks, respectively. Pheromone release rate was calculated as 37 mg/ha/h in 1989.