Efficacy of sulfoxaflor against Asian citrus psyllid (Diaphorina citri ) under laboratory and field conditions

The Asian citrus citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae) transmits a gram negative, phloem limited bacterium that causes huanglongbing, otherwise known as citrus greening disease. Frequent and repeated use of neurotoxic insecticides against D. citri has resulted in development of insecticide resistance. To break the development of insecticide resistance, there is a need for insecticides of newer modes of action for incorporation into psyllid management programs. Sulfoxaflor is the first sulfoximine compound, with a newer mode of action developed for the control of sap-sucking insects.  In the present study, we evaluated the toxicity of, sulfoxaflor to D. citri in laboratory and field conditions. In addition, we also investigated the development, feeding behavior and settling preference of D. citri on the surfaces treated with sulfoxaflor. Sulfoxaflor exhibited toxicity similar as imidacloprid to D.citri in leaf dip bioassay. The LD₅₀ and LD₉₀ values calculated for sulfoxaflor were 5.7 and 90.0 µg AI ml^-1. The egg production, first-fifth instar development and adult emergence was reduced on plants treated with 0.6-48.2 µg AI ml^-1 of sulfoxaflor as compared with untreated plants. The D. citri adults fed less on the surface treated with sulfoxaflor, with concentration as low as 0.3 µg AI ml^-1 causing reduced feeding  as compared to control.  There was no effect on the settling behavior of D. citri on the treated surfaces with sulfoxaflor. Under field conditions, the foliar sprays of sulfoxaflor significantly reduced the number of D. citri adults and nymphs as compared with control treatments. The results suggest that sulfoxaflor is a valuable tool that can be included in to D.citri management program.