The date palm scale, Parlatoria blanchardii (Targioni-Tozzetti) is a target pest of date palm trees causing severe damage resulting in early leaves drop and yield reduction. In the current study, the approximated numbers, occurrence date, size of the generations and their peaks of P. blanchardii were determined during two succesive seasons (2010/2011 & 2011/2012) in order to predict the degree day's units and annual generation peaks using the relationship between the accumulated thermal heat units expressed as degree-days (DD's) and the population fluctuations of insect that help to find out a proper controlling time. The obtained results revealed that the date palm scale has four field generations under the climatic conditions in Luxor Governorate. The winter generation in the two studies seasons was the longest and biggest one than the other three generations. A discrepancy average of -24.8 and -28.5 days between observed and expected peaks was recorded for the two studied seasons, respectively. The general deviation average indicated delay in the expected peaks compared to the observed peaks with an average of 26.6 days. Based on the obtained results, four periods (beginning of October, mid-November to mid of December, mid –April & beginning to mid-June) could be recommended as ideal time for the chemical control of this pest.