Submitted to: Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 9/30/2010
Publication Date: 11/1/2010
Citation: Serikawa, R.H., Okuma, D.M., Backus, E.A., Rogers, M.E. 2010. Effects of the residual activity of foliar-applied insecticides on Asian citrus psyllid (Diaphorina citri) feeding behavior. Entomological Society of America Annual Meeting, Dec 12-15, 2010, San Diego, CA Available:http://esa.confex.com/esa/2010/webprogram/Paper50064.html. Interpretive Summary:
Technical Abstract: Citrus greening disease, also known as Huanglongbing (HLB), is associated with a phloem-limited bacterium that is transmitted by Asian citrus psyllid, Diaphorina citri Kuwayama. Application of insecticides to reduce psyllid populations is one of the primary methods used for HLB management. However, efficacy of insecticides to disrupt psyllid feeding behaviors associated with pathogen acquisition and inoculation has not been previously determined. In this research, Electrical Penetration Graph (EPG) technology was used to correlate feeding behaviors of D. citri with successful pathogen acquisition and inoculation on citrus plants treated with one of five different insecticides: chlorpyrifos (Lorsban 4E), fenpropathrin (Danitol 2.4EC), imidacloprid (Provado 1.6F), spinetoram (Delegate WG) and spirotetramat (Movento 240SC). All five insecticide treatments were tested simultaneously and untreated sour orange plants were used as controls. To replicate field conditions, treated plants were weathered outdoors during summer for 1 day, 1, 2, 3, or 4 weeks prior to EPG recording of psyllids on mature leaves. Non-sequential feeding parameters for each treatment were compared using ANOVA. Results to date show that after 2 – 3 weeks of weathering, foliar-applied fenpropathrin prevents all but a few brief, non-phloem probes and kills psyllids within 6 h. In contrast, chlorpyrifos application weathered for 2 – 3 weeks does not kill insects and feeding is similar to controls. Therefore, insecticides have strong effects on insect feeding, which can be quickly and easily assessed with EPG.