Dinotefuran

All chemical agents tested were of analytical standard grade. Chlorogenic acid (Chemical Abstracts Service [CAS] #327-97-9), abamectin (CAS #71751-41-2), flupyradifurone (CAS #951659-40-8), cyantraniliprole (CAS #736994-63-1), imidacloprid (CAS #138261-41-3), thiamethoxam (CAS #153719-23-4), flonicamid (CAS #158062-67-0), acetamiprid (CAS #160430-64-8), clothianidin (CAS #210880-92-5), nitenpyram (CAS #150824-47-8), and dinotefuran (CAS #165252-70-0) were purchased from Sigma Aldrich (Shanghai, China). Afidopyropen (CAS #915972-17-7) and sulfoxaflor (CAS #946578-00-3) were purchased from Dr. Ehrenstorfer (Augsburg, Germany).

Standards and chemicals of dinotefuran, thiacloprid, and imidaclothiz were purchased from Sigma-Aldrich (United States). The chemical structures of the three NEOs are displayed in Table 1. Methanol (HPLC grade) was purchased from Merck (Germany). The remaining reagents, which were at least of analytical grade, were purchased from Aladdin Reagent (China).
Common duckweed (L. aequinoctialis DKLe0261)¹ was obtained from the China Culture Collection of Aquatic Plants (Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China). L. aequinoctialis was surface-sterilized by soaking in 75% ethanol for 3 min followed by treatment with 0.5% sodium hypochlorite for 5 min. Plant sterility was ascertained by incubating the plant tissues on Luria Bertani (LB) agar (yeast extract, 5 g L⁻¹; tryptone, 10 g L⁻¹; NaCl, 10 g L⁻¹) at 30°C for 48 h and checking for the absence of bacterial contamination. The sterilized plants were successively cultured in flasks containing sterile Hoagland medium in a growth chamber (8,000 lux; 16:8 h light–dark cycle) at 24°C. Hoagland medium contained 293 mg L⁻¹ K₂SO₄, 36.1 mg L⁻¹ KNO₃, 103 mg L⁻¹ MgSO₄·7H₂O, 147 mg L⁻¹ CaCl₂·2 H₂O, 5.03 mg L⁻¹ NaH₂PO₄·2H₂O, 0.95 mg L⁻¹ H₃BO₃, 3.33 mg L⁻¹ FeSO₄·7H₂O, 0.08 mg L⁻¹ ZnSO₄·7 H₂O, 0.39 mg L⁻¹ MnCl₂·4H₂O, 0.03 mg L⁻¹ CuSO₄·5H₂O, 0.39 mg L⁻¹ MnCl₂·4 H₂O, and 0.23 mg L⁻¹ H₂MoO₄.