CERTAIN ECOLOGICAL ASPECTS FOR Icerya seychellarum (Westwood) ON COFFEE PLANTS Coffea arabica IN EGYPT

Certain ecological aspects of the Seychellarum mealybug, Icerya seychellarum (Westwood) which is considered as a key pest on coffee trees, a promising newly crop cultivated in Egypt, have been investigated under two different ecosystems throughout two years, 2009 2011.Results revealed that this mealybug species was found all the year round in both localities. The total population recorded four peaks of seasonal abundance in both investigated ecosystems on coffee trees and it passed through three overlapping generations in both ecosystems.The main weather factors, four weeks earlier, showed miscellaneous effects on the population dynamics of this mealybug species. Means of minimum and maximum temperature had a positive significant effect; while mean percentage of relative humidity showed insignificant effect in the two localities. The combined effects of the four weather factors, as a group, had significant effects on I. seychellarum population throughout both years. In Qalyubyia Governorate (2009), the percentage of explained variance was 56.8%; while in Giza Governorate (2011), this value was 65.9%