Determining the most appropriate chemical control time for codling moth, Cydia pomonella (Lepoptera: Tortricidae), using pheromone traps and day-degree in Mahabad region

Codling moth, Cydia pomonella L. (Lepoptera: Tortricidae), is the key pest of apple orchards in Mahabad and West Azarbaijan province. To determine the best spraying time, male adults’ emergence was studied in Mahabad during 2016. Three types of delta, cylindrical and funnel-shaped traps were used in an apple orchard (5 hectare) in a randomized complete block design. The efficiency of three style pheromone traps was compared. According to the data obtained from regional weather station and larval activity, degree-day model was prepared. It was found that adults appeared in late spring and was showing four populations peaks during growth season. The results showed that there was a significant difference between the traps In terms of trapping male adults (P≤0.05). On the basis of the data available by funnel-shape traps, the results showed that 168.3, 722 and 1301.9 degree-days were required for egg eclosion at first (winter), second and third generation, respectively. Also, on the basis of the data available by delta and cylindrical-shape traps, the results showed that 154.2, 538.1 and 1198 degree-days were required for egg eclosion at first, second and third generation, respectively. On the basis of the data available by funnel traps the chemical control time was determined to be 10-14 May, 1-5 July and 9-14 August 2016 for three generation. Also, on the basis of the data available by delta and cylindrical traps, the chemical control time was determined to be 7-11 May, 17-21 June and 2-6 August for three generation. The comparison of means showed that the funnel traps had the most capture with means values of 41.00±8.64, 26.34±3.18, 85.67±19.37 and 73.67±3.89 number of male adults for wintering, first, second and third generation, respectively. Also, the cylindrical traps had the least capture with means values of 11.34±1.20, 5.67±1.76, 13.67±2.73 and 53.67±3.16 number of male adults for wintering, first, second and third generation, respectively.