ARS | Publication request: Gender differences and effect of photophase on Asian citrus psyllid (Diaphorina citri Kuwayama) feeding behavior

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 16, 2011
Publication Date: July 11, 2011
Citation: Serikaw, R.H., Okuma, D.M., Backus, E.A., Rogers, M. 2011. Gender differences and effect of photophase on Asian citrus psyllid (Diaphorina citri Kuwayama) feeding behavior. Meeting Abstract. Available: http://www.infobibos.com/Hemipteran/CD/authors.html.

Technical Abstract: Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), thought to be primarily a phloem-feeding insect, transmits the presumptive pathogen for Huanglongbing, ‘Candidatus Liberibacter asiaticus’. Because this bacterium is restricted to the phloem and bacterial transmission is the result of psyllid feeding, investigation of the basic feeding behavior of D. citri is needed. In this study, an electrical penetration graph (EPG) monitor was used to: 1) determine whether gender-based differences in feeding behavior exist for D. citri and 2) examine the effects of photophase on D. citri feeding activities. In the first experiment, investigating gender-based differences in D. citri feeding behavior, overall, the number of male D. citri reaching the phloem was 20% higher compared to females. However, the mean duration of phloem ingestion (waveform E2) per insect was significantly higher for female D. citri compared to males. Analysis within treatments (gender) showed that, despite being considered a phloem feeder, the duration of xylem ingestion (waveform G) and phloem ingestion (waveform E2) were not significantly different. Prominent xylem ingestion was probably not caused by desiccation due to trauma, because insects were not anesthetized, starved or damaged during wiring. In the second experiment, examining the effects of photophase on D. citri feeding, within-treatment analysis showed that non-probing activities (waveform z and np), phloem penetration and salivation (waveform D and E1, respectively), and xylem ingestion (waveform G) were generally longer in duration per insect during the light photophase. In contrast, stylet pathway activities (waveform C) and phloem ingestion (waveform E2) were longer in duration during the dark photophase. Thus, results suggest that gender and photophase have an influence on D. citri feeding behavior, and are variables that could affect the outcome of experiments investigating transmission of ‘C. Liberibacter asiaticus’ by D. citri.