Abstract
The Results of studying the effect of some ecological factors and Ana and Vestibella apple varieties on seasonal activity of leafroll aphid Dysaphis reanmuri and Dysaphis pyri, showed a significant effect on mean number of the two aphid species a ccording to the season, apple variety and direction, the highest mean aphid number reached 25.47 Aphid/Leaf on East direction on Vestibella variety for the season 2010 The results also exhibit a significant variation between the general mean number of aphids according to the direction and reached 23.16, 9.62, 7.74 and 13.46 Aphid/leaf for East, West, North and South direction respectively. The regression equations between the mean number of aphids and biotic and abiotic factors showed a clear effect on mean aphid seasonal activity and the rain exhibit ahighest effect on mean aphid number and reached ٪66 – 6 while the effect of wind and temperature on mean number of parasites were 67. and 59.6% respectively.
