The pyralid borer, E.saccharina W., (Lepidoptera-Pyralidae) is one of the economic pests of sugarcane and certain other grarninaceous crops in South Africa. Due to the high infestation with this pest in papyr‌us fields in Egypt in recent few years, the present investigation was car-ried out to study the distribution of larvae in the umbels of different ages at harvest. The results could be summarized as follows: The mature umbels of Cyperus papyrus with old reproductive structures (MO) received the highest infestation rate (60.7%) during the season followed by mature umbels with young reproductive struc‌tures (MF); (51.4%), the mature umbels with no reproductive structures (MN); (35.1) and young umbels (Y); (34.9%). On the othe hand, MO and ME categories harboured the least number of larvae/infested umbel (1.3) compared with 1.5 and 1.4 for (Y) an (MN) categories, respectively. Regardless of the umbel age the Fourth and fifth instars represented the majority of larvae (136) and (129) compared with second and third instars (69) and (78), respec-tively. It is also noticed that the mature deformed umbels, with no chlo‌rophyl, had no larvae.