The present investigation was carried out at Aga district (El-Dakhalia Governorate) during 2005/2006 and 2006/2007 seasons to evaluate the seasonal activity of the ectoparasitoids; Exeristes roborator (F.) and Parasierola sp. on the diapausing pink bollworm (PBW), Pectinophora gossypiella (Saunders) larvae. Studies on the factors causing mortality among the diapausing pink bollworm. P. gossypiella  larvae indicated that E. roborator (Fam., Ichneumonidae) and Parasierola sp. (Fam., Bethylidae) were mainly observed associated with the (PBW) larvae. The total mortality fluctuated considerably from one month to another during diapausing period. The key factor analysis suggested that E. roborator exhibited a positive density- dependent responses. However, Key –values of E. roborator were more correlated with the host density than the other mortality factors. On the contrary, the parasitoid Parasierola sp. showed no density dependent response. Predatism by the predacious mites and natural mortality are in most cases able to cause high percentage of mortality at all host population level, but no density- dependent responses to increase host populations have been recorded.