Flupyradifurone induces transgenerational hormesis effects in the cowpea aphid, Aphis craccivora

With low-dose stimulation and high-dose inhibition, insecticide-induced hormesis, a biphasic phenomenon, can contribute to pest resurgence. The cowpea aphid, Aphis craccivora (Koch) (Homoptera: Aphididae), is a vital insect that infests legume crops. Its hormesis of flupyradifurone has not been previously established. Age-stage two-sex life analysis is used to investigate the sublethal and transgenerational effects of flupyradifurone on two successive generations of A. craccivora. A leaf-dip bioassay method revealed high toxicity of flupyradifurone against A. craccivora, with lethal concentration 50% value (LC50) of 1.82 mg L-1 after 48 h exposure. Treatment of parent generation (F-0) with LC10 and LC25 of flupyradifurone significantly increased the longevity and fecundity of the directly exposed adults. The results of transgenerational effects showed that the treatment of (F-0) with LC25 induced significant hormetic effects in progeny generation (F-1). Furthermore, flupyradifurone at LC25 significantly enhanced the biological traits, such as intrinsic rate of increase (r), finite rate of increase (lambda), and net reproductive rate (R-0) compared with the control. Similarly, both LC10 and LC25 induced a significant increase in the mean generation time T (d). Conversely, both treatments caused a significant decrease in the doubling time (DT). Data in the present study demonstrate that the exposure of (F-0) to flupyradifurone at LC10 and LC25 enhanced longevity and fecundity in the directly exposed adults of A. craccivora, and induced transgenerational hormesis across the subsequent (F-1) generation. These results should be taken into consideration when using flupyradifurone for controlling cowpea aphid.