the seychelles fluted scale, Icerya seychellarum (Westwood) (Monophlebidae: Hemiptera) is a serious pest of mango in Egypt, while it causes yield loss in most of mango orchards all over the country. The economic threshold level is a key factor to start control program. Results of statistical analysis shown that, when population density of I. seychellarum were (27.24 & 27.22) pre-adult / leaf) in March and June infestation, respectively. These numbers could be regarded as economic threshold of infestation with I. seychellarum on mango trees, at this level sufficient time for initiation of control measures. Population of I. seychellarum showed four annual generations and four activity peaks; a small peak in mid-March, intermediate peak in June, the third peak in August and last peak in mid-September.