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

Abstract

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 (F0) 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 (F0) with LC25 induced significant hormetic effects in progeny generation (F1). Furthermore, flupyradifurone at LC25 significantly enhanced the biological traits, such as intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R0) 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 (F0) 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 (F1) generation. These results should be taken into consideration when using flupyradifurone for controlling cowpea aphid.