Results of long-term use of pheromone traps to monitor harmful tortricid moths in Leningrad Region of Russia

Monitoring the population dynamics of harmful moths using synthetic sex attractants in Leningrad Region was carried out in the fruit experimental orchard of St. Petersburg Agrarian University (Pushkin) and small private orchards of Pushkin district. As a result of the analysis of many years temperature characteristics of vegetation seasons in the Leningrad Region and calculation of the sums of effective temperatures, it has been found that the codling moth had high numbers and developed in two full generations in 1999, 2002, 2006, 2013 and 2018. The complex of phytophagous leaf rollers as a whole can cause sometimes significant harm to both industrial orchards and homestead lands, because the economic threshold of harmfulness by yield losses is often achieved, when plants are damaged by more than one pest species, each of which causing only weak harm. As a general conclusion, the complex of orchard leaf rollers is a dynamic system. Their development and numbers ratio is influenced by weather conditions of a year and climate changes in general.