Using degree-days model to determine the optimum spray timing for the codling moth Cydia pomonella (L.) (Lep., Olethreutidae)

Successful spraying against Cydia pomonella (L.), the main pome fruits pest in Iraq orchards, depends on correct timing, which was determined by the degree-days model or at intervals of 100 ° 10 degree-days after the biofix. Sprays are most effective against the newly hatched larvae before entry into the fruits. The optimum timing with laresban treatments was determined to be at 200 degree-days after the biofix or after an average degree-days accumulation of 195 DD (SD = 59) and 298 DD (SD = 67) when daily degree-days calculated by the method of the sine-wave.