Demography and parasitic effectiveness of Aphelinus asychis reared from Sitobion avenae as a biological control agent of Myzus persicae reared on chili pepper and cabbage

Abstract

To develop a bank plant system for the biological control of vegetable aphids, we used wheat, Triticum aestivum L., as a host plant to rear the English grain aphid, Sitobion avenae Fabricius, as an alternative host for rearing the parasitoid Aphelinus asychis Walker. A. asychis reared from S. avenae were allowed to parasitize second instar Myzus persicae nymphs feeding on chili pepper and cabbage plants. We compared the life history and life table parameters of A. asychis, including development time, pupal mortality, sex ratio, longevity, fecundity and host-feeding of the F1 generation. The data were analyzed using the age-stage, two-sex life table method. We found that the parasitoids reared from S. avenae could successfully parasitize and host-feed M. persicae on chili pepper and cabbage, but they performed differently when the aphids on the two host plants were offered. The parasitoids had a shorter developmental duration, higher proportion of female progeny, longer longevity, higher fecundity and feeding rate when parasitizing the aphids on chili pepper than on cabbage. Based on the life table parameters, the including intrinsic rate of increase (r), net reproductive rate (R0) and net aphid killing rate (Z0), A. asychis reared from S. avenae performed better as a biological control agent of M. persicae on chili pepper than on cabbage.