Effects of different garden pea cultivars on population parameters of green morph of pea aphid (Acyrthosiphon pisum)

Pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: aphidiae), is a destructive agricultural pest of a wide range of leguminous crops. Pea aphids have strong reproductive capacity, especially green morph of pea aphid. To build the theoretical basis for garden pea variety selection and comprehensive treatment for A. pisum, the effects of four different garden pea cultivars ("Grass pea", "Dingwan1", "Dingwan2" and "G1997") on population change of green morph of A. pisum were investigated under constant temperature (23±1) ℃, relative humidity (70%~80%) and illumination time (16 h). The study determined the demographic characteristics of the green morph of A. pisum, including population parameters, developmental duration, fecundity and survival. The results showed significant differences in the durations of different developmental stages and highest fecundity per female lifetime of the green morph of A. pisum in the four different garden pea cultivars. The generation was longest (17.92 d) in "G1997" and shortest (12.69 d) in "Grass pea". The highest fecundity per female lifetime (117) was in "G1997" and the lowest (60) in "Grass pea". All the survival curves were of Deevey type I. The net reproductive rates (R₀) were 40.569 2, 37.952 4, 31.607 8 and 25.000 0 in "Dingwan2", "Dingwan1", "G1997" and "Grass pea", respectively. The intrinsic rate of increase (r_m) was maximum (0.275 8) in "Dingwan1" and minimum in "G1997". The survival rate was highest in "G1997", followed by "Dingwan2", "Dingwan1" and "Grass pea". The time (t) for population doubling of the green morph of A. pisum in "G1997", "Dingwan2", "Grass pea" and "Dingwan1" was 3.675 0 d, 2.867 6 d, 2.729 8 d and 2.513 1 d, respectively. Furthermore, the mean generation time (T) was minimum (12.679 3 d) in "Grass pea" and maximum (18.314 5 d) in "G1997". The results indicated that green morph of A. pisum population in the pea cultivars decreased in order of "Dingwan1" > "Dingwan2" > "Grass pea" > "G1997".