Cotton aphid (Aphis gossypii Glover) is a harmful pest that affects cotton crops in Xinjiang, China. Afidopyropen is a new type of insecticide that exerts a strong control effect on piercing-sucking pests. In this work, Highperformance liquid chromatography (HPLC) was used to assess afidopyropen residues on different cotton parts following foliar spraying and root application. The effects of agent retention on physiological indices of cotton aphids and preventive effects were investigated. The results showed that different application methods had a strong influence on afidopyropen residues, most of which were in cotton roots, with fewer in stems and leaves. Enzyme activity analysis showed that the carboxylesterase activity of A. gossypii was significantly increased under different application methods. Foliar spraying and root application (hydroponics) of afidopyropen had rapid, potent effects against A. gossypii, while root application (soil cultivation) did not have a significant effect, but had a positive effect by day 14. Elucidation of the effects of the two application methods to the physiological indices and control of A. gossypii provide a theoretical basis for the development and promotion of integrated water-pharmaceutical technologies for afidopyropen spraying and drip irrigation in cotton fields in Xinjiang and elsewhere.
Afidopyropen has high activity against pests. However, it poses potential risks to the soil ecology after entering the environment. The toxicity of afidopyropen to earthworms ( Eisenia fetida ) was studied for the first time in this study. The results showed that afidopyropen had low level of acute toxicity to E. fetida . Under the stimulation of chronic toxicity, the increase of reactive oxygen species (ROS) level activated the antioxidant and detoxification system, which led to the increase of superoxide dismutase (SOD) and glutathione S-transferase (GST) activities. Lipid peroxidation and DNA damage were characterized by the increase of malondialdehyde (MDA) and 8-hydroxy-2 ' -deoxyguanosine (8-OHdG) contents. Meanwhile, the functional genes SOD , CAT , GST , heat shock protein 70 ( HSP70 ), transcriptionally controlled tumor protein ( TCTP ), and annetocin ( ANN ) played a synergistic role in antioxidant defense. However, the comprehensive toxicity of high concentration still increased on the 28th day. In addition, strong histopathological damage in the body wall and intestine was observed, accompanied by weight loss, which indicated that afidopyropen inhibited the growth of E. fetida . The molecular docking revealed that afidopyrene combined with the surface structure of SOD and GST proteins, which made SOD and GST become sensitive biomarkers reflecting the toxicity of afidopyropen to E. fetida . Summing up, afidopyropen destroys the homeostasis of E. fetida through chronic toxic. These results provide theoretical data for evaluating the environmental risk of afidopyropen to soil ecosystem.