Effect of imidacloprid application on Asian citrus psyllid (Diaphorina citri Kuwayama) (Hemiptera: Psyllidae) feeding behavior and successful transmission of the bacterial pathogen Candidatus Liberibacter asiaticus

The Asian citrus psyllid, Diaphorina citri (Kuwayama) is one of the most important pests of citrus since it vectors Candidatus Liberibacter asiaticus, the bacteria associated with citrus greening disease. The use of insecticides for vector control is the primary method of managing the spread of this pathogen. Imidacloprid is an insecticide commonly applied to the root zone of young citrus trees to provide systemic protection from pests. The effects of imidacloprid on feeding behavior of D. citri have not been studied in much detail. Thus, the purpose of this study is to determine the effects of imidacloprid application on feeding behavior of D. citri, and to determine whether use of this systemic insecticide will have any direct effect on pathogen transmission by D. citri. Detailed examination of psyllid feeding behavior was conducted using an electrical penetration graph (EPG) system to monitor and record feeding behaviors of pathogen containing psyllids on imidacloprid treated and untreated citrus plants. Feeding waveforms were recorded for 12h but psyllids remained on the plants for 24h to allow an adequate innoculation access period. The experiment was replicated 20 times, and each plant received a single psyllid. Waveforms recorded were identified based on recent EPG studies where the biological significance of the waveforms were correlated with D. citri feeding behavior. Results of this study completed to date will be presented.