Ecological Studies were carried out on the white peach scale insect, Pseudolacaspis pentagona (Targioni) at Meet-Ghamer, Dakahliya Governorate throughout two successive years started from February 1977 till January 1999. The study of the first year showed that the total population of P. pentagona had five peaks recorded on mid February, early of April, July, November 1997 and January 1998. In the second year of investigation, peaks were recorded on mid of March, May, July, early November and mid December 1998. The study clearly showed that the nymphal stage had four high infestation periods through the 1^st and 2^nd year of investigation. The same results were recorded for P. pentagona adult females, while results concerning the ovipositing females had a curve of three peaks. The study of seasonal abundance of Aphytis sp. as a mortality biotic factor showed that the total population of Aphytis sp. parasite had five peaks; the first started from early February till early April, the second main peak started from early November 1997 till mid January 1998. In the second year of investigation, the parasitoid total population had a curve of six peaks. On the other hand, the larval stage of Aphytis sp. recorded five annual peaks on early March, mid April, early of June, August 1997 and early January 1998. However, the pupal stage showed low density in compared with the larval stage. The percentage of parasitism of Aphytis sp. immature stage had a curve of five peaks in the two years; the highest one on mid January 1998, 1999 in the first and second year of investigation, respectively.