DEGREE - DAYS FOR MONITORING CODLING MOTH GENERATIONS AS A SIGNIFICANT ELEMENT OF IPM IMPLEMENTATION

Sseasonal changes in the population of codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae) was studied in three different regions in Syria, i.e. El-Marrana (Tartous Governorate), Daher El- Jabal (As-Sweida Governorate) and Sirghaya (Rif Dimashq Governorate) using sex pheromone traps in conjunction with the day-degrees (DD °C) model. Results show that the codling moth had three generations in El-Marrana, and two generations in both the Daher El-Jabal and Sirghaya. The accumulation of day-degrees in El-Marrana during the first, second and third generations were 518.6, 497.3 and 430.3 DD °C, respectively, whereas these degrees were 427.6 589 and 502 558.5 DDC in the two generations of Daher El-Jabal and Sirghaya, respectively. On the other hand, the relationship between the two environmental factors mean temperature and length of day and population density of the codling moth indicated a positive significant correlation coefficients for both factors. In the contrary data revealed a non significant correlation coefficients with the relative humidity.