Effects on Asian citrus psyllid (Diaphorina citri Kuwayama) feeding behavior of fenpropathrin and chlorpyrifos within 24 hours of application

Huanglongbing (HLB), also known as citrus greening disease, is one of the most destructive diseases affecting citrus production. The phloem-limited bacterium that causes HLB is transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). One component of HLB management is the use of insecticides to slow the rate of pathogen spread by reducing vector populations. However, the efficacy of pesticide applications in preventing inoculation of health plants with HLB pathogen via disruption of psyllid feeding behaviors is undetermined. In this study, the effect of two foliar insecticides on D. citri feeding behavior was examined using an Electrical Penetration Graph (EPG) monitor. The first insecticide evaluated was a pyrethroid (Danitol 2.4 EC), and the second was an organophosphate (Lorsban-4E). Psyllids were recorded on young leaves. Untreated sweet orange plants were used as controls in both experiments. The psyllid feeding access period was 6 h on pyrethroid-treated plants, and 12 h on the organophosphate-treated plants. Non-sequential feeding parameters were analyzed by ANOVA (PROC GLIMMIX, SAS Institute 2001). The results of this study will be discussed with regards to the ability of these insecticides to protect citrus from HLB infection.