Abstract
European cherry fruit fly (Rhagoletis cerasi) is the key pest of sweet and sour cherry throughout Europe. Pest management is usually based on pesticide application. The key of successful management is knowing the proper time of pesticide application, based on the phenological model. To develop a phenological model, a local population of the pest from the northern part of Bosnia and Herzegovina was studied. First adult appearance and population densities were monitored by yellow sticky traps. Soil and air temperatures were compared at two thermal thresholds, 5 °C and 7 °C. Air temperature was applied in the model since it is more suitable for farmers and is related to soil temperature. Both thermal thresholds can be used. The first adult flies were captured after 435 degree-days (dd) and the first cumulative 5% of the catch after 605 dd. These two times should be considered for time of application of pesticides. Regarding time for first egg hatch, the first larva burrowed into fruits at 730 dd. Cultivars that can be harvested beginning on the 730 dd calculate from 1 March are considered to have low risk of cherry fruit fly damage.