Untersuchungen zur Paarungsstörung des Erbsenwicklers (Cydia nigricana) mit Sexualpheromon

Summary

The pea moth (Cydia nigricana, Lep. Tortricidae) has developed to a serious pest in various parts of Germany, particularly in organic vegetable peas and protein seed peas. The prospects of mating disruption (MD-control) utilizing synthetic C. nigricana sex- pheromone were investigated in field trials in 2004-2006.
Objectives were to gather basic technical data concerning the dispenser material, field dosage and evaporation rates under field conditions in commercial pea stands, re-spectively. Pheromone-treated and untreated fields of at least 2ha were compared pairwise concerning the percentage of infested pea pods at green picking stage, age structure of larvae and final infestation rates in harvested material. In addition in 2005 and 2006 cages were placed in the centre of pheromone-treated and untreated fields. Cellulose dispensers (600 ha-1) loaded with a total of 200 g E8, E 10-dodekadien-1-yl- acetat ha-1) were hung manually on pea main shoots before moth flight activity com-menced, monitored with Tripheron®-monitoring delta traps. A few days after applica-tion unmated pairs of moths were introduced into the treated and untreated cages to assess the same infestation parameters as in the open surrounding pea field.
Pheromone treatments reduced pea pod infestation in field cages consistently to 78% in average. In the open field, pheromone treatments led also to a reduction, however, MD-control was less efficient with 31% in average. It is concluded that from the tech-nical side, mating disruption has an effect on pea moth infestation, particularly under caged conditions. Its relatively lower efficacy in the open field is supposed to be re-lated to an unknown extent to gravid female entry. Results and prospects of MD-control trials incorporating the crop border and the involvement of eclosion site- treat-ments are presented and discussed.