Lethal and sub-lethal effects of Clothianidin and summer oil on the life table parameters and population trend of the cabbage aphid, Brevicoryne brassicae (Hem.: Aphididae)

Cabbage aphid, Brevicoryne brassicae L., is one of the most important pests of cruciferous crops worldwide. In the present study, the lethal (LC50) and sublethal (LC25) effects of Clothianidin and summer oil were investigated on biological properties and population growth rate parameters of cabbage aphid under greenhouse conditions. The leaf dipping method containing aphid adults was used for bioassays. The life table data were analyzed based on the age-stage, two-sex life table theory. Results indicated that Clothianidin affected the population growth rate of aphids by prolongation of the pre-adult stages, decreasing survival rate, adult longevity, and reproduction in comparison to summer oil. The lowest fecundity rate (14.14 nymphs per female) was recorded in Clothianidin treatment. The lowest and highest intrinsic rate of increase (r) was observed in Clothianidin (0.2123 day-1) and control (0.3636 day-1), respectively. The results also demonstrated that population growth of the cabbage aphid in different treatments was exactly in consistent with the estimated population growth parameters. For example, aphids treated with Clothianidin, had slower growth rate and, thereby prolonged mean generation time (T). The overall results demonstrated that Clothianidin could be considered as an effective insecticide in the management of cabbage aphid.