Comparison of Growth Population Parameters of Aphidius matricariae (Hym., Aphidiidae) on Host aphid, Aphis fabae Scopoli (Homoptera: Aphididae), on Four Varieties of Sugarbeet in Laboratory Conditions

Aphidius matricariae Haliday (Hym., Aphidiidae) is one of the most important parasitoids of numerous aphids which is used in pest management programs. In this research, growth population parameters of A. matricariae were studied on Aphis fabae Scopoli (Hom., Aphididae) on four varieties of sugar beet (IC, PP8, Rasoul and Shirin). Experiments were carried out in a growth chamber with temperature of 25±1ºC, 70±5 % RH and a photoperiod of 16L: 8D hours. Twenty newly emerged adult wasps were separately released in leaf cages containing 50 nymphs of aphids. After 24 hours parasitoids were placed in other leaf cages with the same conditions and was continued until the parasitoids death. The parasitized aphids on each variety were counted daily. The results were analyzed according to Jackknife method with SAS and MINITAB statistical softwares. In this research, the net reproductive rates (Ro) on IC, PP8, Rasoul and Shirin cultivars were 13.31, 18.18, 16.54 and 18.58 female/female/generation, intrinsic rate of increase (rm) were 0.360, 0.406, 0.401 and 0.408 female/female/day, mean generation time (Tc) were 7.18, 7.14, 6.99 and 7.17 days and doubling time (DT) were 1.92, 1.70, 1.73 and 1.67 days, respectively. The results showed that host plant varieties affect the growth population parameters of parasitoid.