LIFE HISTORY AND DEMOGRAPHIC PARAMETERS OF APHIS FABAE (HEMIPTERA: APHIDIDAE) AND ITS PARASITOID, APHIDIUS MATRICARIAE (HYMENOPTERA: APHIDIIDAE) ON FOUR SUGAR BEET CULTIVARS

Abstract

The black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae) is one of the important pests of sugar beet in Iran. Aphidius matricariae Haliday (Hymenoptera: Braconidae, Aphidiinae) is a key parasitoid used in various integrated pest management (IPM) programs worldwide. This study was conducted to determine the effects of four cultivars of sugar beet (IC, PP8, Rasoul and Shirin) on biology and demographic parameters of A. fabae and A. matricariae as a step toward biological control of black bean aphid. Experiments were performed in a growth chamber with 25±1oC, 70±5 % RH and a photoperiod of 16L : 8D hours. Survival rates (lx) of A. fabae and A. matricariae were highest on Rasoul and PP8 cultivars, respectively. The life expectancy of 1-day-old adults of A. fabae and A. matricariae was estimated to be 4.25, 4.3, 4.15, 4.5 and 3.8, 3.8, 3.45, 3.65 days on IC, PP8, Rasoul and Shirin cultivars, respectively. There were significant differences between rm values of A. fabae and A. matricariae on PP8, Shirin and Rasoul cultivars. There were no significant differences between net reproductive rates (Ro) of A. fabae on different cultivars of sugar beet, while there were clear differences in Ro values of A. matricariae on various cultivars. The highest value of Ro for A. matricariae was obtained on Shirin cultivar. The parasitoid performed better on Shirin than other cultivars, while the aphid performance was poorly affected by cultivars. Therefore, we suggest the use of Shirin cultivar to maximize the natural biological control of A. fabae by A. matricariae.