BIOLOGICAL CONTROL OF CODLING MOTH, CYDIA POMONELLA (L.) IN APPLE ORCHARDS OF BULGARIA USING GINKO® DISPENSERS

The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is a significant pest of pome fruit and walnut orchards worldwide and it is a particular problem in Bulgaria. Codling moth resistance to many insecticides has been recently detected in Bulgaria. Codling moth (CM) mating disruption with Ginko® dispensers was evaluated in four successive years from 2019 to 2022 as part of an anti-resistance strategy. In an isolated 3 ha apple orchard in the Plovdiv district of South-Central Bulgaria, close to the town of Perushtitsa, field tests were conducted for the control of the codling moth (CM), C. pomonella, via mating disruption (MD) using pheromone Ginko® dispensers. The pheromone dispensers were hung in the upper third of tree canopies with a density of 500 dispensers/ha before CM flight started. Dynamics of CM flights was monitored by pheromone traps installed in the trial plot and in a conventionally treated reference orchard. Two types of baits were used in the traps: PHEROCON® CM L2–codlemone lures and PHEROCON® CM DA COMBO-P + AA lures (Trécé Inc., USA) in the orchards for mating disruption. The PHEROCON® CM L2 lures were changed at 4-week intervals and PHEROCON® CM DA COMBO-P + AA lures at 8-week intervals. PHEROCON® VI Delta sticky traps baited with PHEROCON CM DA COMBO- P + AA lures and standard CM L2 caps were installed, for comparison, in a reference orchard located in the Plovdiv region. Fruit infestation was periodically assessed till the harvest time. In both years fruit damage remained lower till late July and increased slightly only in August. At harvest, fruit damage remained below 1%. It was obvious that mating disruption could be useful strategy for the control of codling moth in Bulgarian apple orchards, specifically when the plot is isolated from external sources of infestation and the population density of the pest is low.