Ecological studies on the pink bollworm, Pectinophora gossypiella (Saund.) and spiny bollworm, Earias insulana (Boisd.) were carried out at Abo-Hammad district, Sharkia Governorate, Egypt during two consecutive cotton growing seasons of 2007 and 2008.  The obtained results indicated that the pink bollworm male moths catch recorded five peaks during 2007 and 2008 seasons.  The accumulated heat units from peak to peak in the first season 2007  were 412.50, 345.06, 460.97 and 465.40 degree-days, respectively. While in the second season 2008. The accumulated heat units from peak to peak were 318.21, 459.14, 463.79 and 459.76, respectively.On the other hand the spiny bollworm catch recorded four peaks during the same seasons, the accumulated heat units from peak to peak in the first season 2007 were 557.26, 737.01 and 610.37 degree-days of the four peaks, respectively , while in the second season 2008 the accumulated heat units from peak to peak were 698.78, 738.37 and 609.79 degree-days, respectively. Effects of maximum, minimum, mean temperatures and mean of RH % on catch of pink bollworm male moths in pheromone traps were very low in season 2007 (6.44%) and low in season 2008 (28.86%) . Results concerning , relative humidity showed insignificant effect in the 1^st season 2007 comparison to effect  significant in the second season 2008. On the other hand the effects of max., min. and mean temp. onspiny bollworm catch  were significant in season (2007) and insignificant in the 2^nd season, respectively. Results also showed that the mean RH %  had insignificant effect on spiny bollworm catch in the two seasons. Finally effects of all weather factors together were 41.93 and 28.37% in the two seasons, respectively.