The brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), is a serious pest of rice. At present, the application of chemical insecticides is the main control option for this pest. BPH has evolved resistance to various classes of insecticides. Cycloxaprid, a new oxabridged cis-configuration neonicotinoid insecticide, is a (nitromethylene) imidazole analog of imidacloprid. This study focused on the baseline susceptibility to cycloxaprid of 18 field samples of N. lugens collected from nine geographical locations in China, as well as possible cross-resistances between cycloxaprid and other important neonicotinoids in one laboratory-selected resistant strain of N. lugens to imidacloprid. The median lethal concentration (LC50) of cycloxaprid for the 18 samples ranged from 1.26 to 14.90 mg/liter. Furthermore, the cross-resistance studies showed that the imidacloprid-resistant strain exhibited a 27.63-fold resistance to imidacloprid and lower levels of cross-resistance to acetamiprid (16.64-fold), thiacloprid (12.64-fold), and nitenpyram (16.90-fold); however, there was no cross-resistance to cycloxaprid (1.92-fold). These results indicate that cycloxaprid could be an effective alternative insecticide for the management of N. lugens, which is urgently needed to prevent or delay further increases in insecticide resistance in N. lugens.

In order to explore the impact of biochar and green manure on the micro-ecological environment of citrus soil, a field experiment was used to set CK (conventional fertilization), T1 (5.0 kg/biochar) and T2 (5.0 kg/biochar + 10% nitrogen fertilizer reduction + green manure), for measuring the 3 kinds of fertilization affectness to the fungal diversity and community structure of citrus rhizosphere soil. The results showed that, compared with CK, the pH, alkali-hydrolyzable nitrogen, available phosphorus and available potassium content of T1 and T2 treatments were significantly increased, and soil bulk density was significantly reduced. Application of only biochar increased the diversity of soil fungi, but reduced the richness of fungi. Combined application of biochar and green manure significantly increased the diversity and richness of fungi. Application of biochar increased the relative abundance of Basidiomycota, Schizoplasmodiida, and Talaromyces in soil, and decreased relative abundance of Ascomycota, Mucoromycota, Chaetomium and Fusarium. The study shows that the combined application of biochar and green manure can significantly increase the soil fungal diversity, reconstruct community structure of soil fungi, reduce the abundance of pathogenic bacteria, and promote micro-ecological balance in soil for citrus and soil health。