Effect of Different Commercial Almond Cultivars on Biological Responses of Mealy Almond Aphid Hyalopterus amygdali Blanch. in Field Conditions

East Azerbaijan province is one of the major producers of almond and its improved varieties of this priceless species in Iran. Almond trees are attacked by different kinds of pests, such as aphids, during their lifetime. The aphid Hyalopterus amygdali (Blanchard, 1840) is the predominant pest on almond trees in East Azerbaijan province. This pest severely weakens their hosts by eating the phloem sap of leaves and shoots of almond. In this study, antibiosis of five almond cultivars; including Sahand, Shekoofe, Azar, Ferragnes and Ne Plus Ultra; was studied against mealy almond aphid (H. amygdale) in field condition. The estimated variables were the survival rate of nymphal stage, its developmental time, growth index, fecundity and intrinsic rate of population increase (rm) of adult apterous mealy almond aphid. The ANOVA of the data indicated that regarding duration of nymphal developmental time and adult fecundity, there were no significant differences between the cultivars. But, the mean of relevant intrinsic rate of natural increase (rm value) of apterous adult was significantly different between the cultivars (P