Host plant preference, host stage preference and switching behavior of Aphidius platensis (Hym.: Braconidae) to green peach aphid

Green peach aphid, Myzus persicae (Sulzer) (Hem.: Aphididae), is a serious and global pest of vegetable and greenhouse crops. Developing a strategy for the control of this pest and creating a mass-rearing program of its parasitoid Aphidius platensis (Hym.: Braconidae) needs to be examined in terms of host plant preference, host stage preference and switching behavior of A. platensis. Host stage preference and switching behavior carried on third and fourth instars of green peach aphid and host plant preference was studied by sweet pepper and eggplant. All experiments were conducted at 25 ± 1°C, 70 ± 5% RH, and 16:8 h L: D photoperiod. Data analysis showed that A. platensis parasitized all nymphal stages of M. persicae, however, it preferred third and fourth green peach aphid instars. Furthermore, it has been revealed the parasitism rate of A. platensis on pepper-reared aphids (85.5%) was significantly higher than those reared on eggplant (28.5%). It has also been confirmed that the number of parasitized nymphs varied at different ratios of host stages (mixture of third and fourth instars) and the number of host parasitized increased with increasing the contribution of that stage in host stage ratio. These results could be useful to develop a mass-rearing program of A. platensis.