Khadijeh Madahi - Department of Plant Protection, College of Agriculture, University of Guilan, Rasht, Iran
Ahad Sahragard - Department of Plant Protection, College of Agriculture, University of Guilan, Rasht, Iran

Life table parameters of Aphis pomi DeGeer (Hemiptera: Aphididae) were determined on two host plants: apple (Malus pumila L.) and flowering quince (Chaenomeles japonica Lindl.). This study was carried out under laboratory conditions (۲۵ ± ۱ ºC and RH of ۷۰ ± ۵ % and a photoperiod of ۱۶: ۸ h (L: D). The survivorship from first instar nymphs to adult was very close in M. pumila and C. japonica. The longevity of A. pomi was ۸.۱ ± ۰.۴۵۸ and ۹.۶۵ ± ۰.۴۱۲ days and the fecundity of female was ۳۷.۲۵ ± ۲.۱۹۸ and ۳۲.۹ ± ۱.۸۰۲ nymphs on M. pumila and C. japonica, respectively. Peaks of reproductive value occurred at ages of ۸ and ۹ days when reared on M. pumila and C. japonica, respectively. The intrinsic rate of increase (r) on M. pumila was higher than that on C. japonica, as it was ۰.۳۹۶ ± ۰.۰۱۵ on M. pumila and ۰.۳۲۹ ± ۰.۰۰۶ day-۱ on C. japonica. The mean generation time (T) was ۹.۱۳ ± ۰.۳۵ and ۱۰.۶۲ ± ۰.۱۸ days, on M. pumila and C. japonica, respectively. The results showed that the two closely related host plants had significant influence on life table parameters of A. pomi and the aphid showed a better performance on M. pumila than on C. japonica. These results indicated that M. pumila is more suitable for A. pomi, resulting in a higher reproductive performance.

Life table parameters, Green apple aphid, Generation time, Intrinsic rate of increase